75 years of astronomy in review.

-  1909  -  My lifetime in astronomy in review.  Since 1941 I have been seeing stars in the night sky.  Fortunately I happen to have  been entering interesting times in astronomy.  Here are seven decades in review for your reflection.
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-----------------------------  1909  -  My lifetime in astronomy in review.
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-  My 75 years of astronomy and today I have a bookcase that is 12 foot long with astronomy reviews.  The goal is to get to 2,000 reviews.  This one is #1909.  It is a summary of events to look back on.
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-  When I started in 1941 the world was focused on “ Was Mars inhabited?”   Telescopes could see the canals.  Radio telescopes were brand new and there was certainty the signals had been detected that came from aliens in another world.  They turned out to be “Quasars”.
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-  In 1937 the radio telescope was a 31 foot parabolic dish working at 160 megahertz.  The rest of astronomy was “ visible light” only until this radio signal came along.  Then infrared and ultraviolet exploration soon followed.
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-  The biggest development in 1948 was the 200 inch Hale telescope on Palomar Mountain.  The Mount Wilson telescope from 1919 was 100 inch.
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-  World War II and the German V2 rockets launched the space age.  In 1957 the Soviet Union launched the first artificial satellite, the 23 inch Sputnik I on the nose of a rocket.
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-  In 1958 the U.S. launched Explorer I and detected the Van Allen radiation belts surrounding Earth.  The U.S. also launched NASA that year.
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-  In 1963 we first realized that Quasar spectra were emission lines of hydrogen absorption extremely redshifted due to their light travel over great distance.
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-  July 20, 1969, Apollo 11 landed Neil Armstrong and Buzz Aldrin on the Moon.  Arno Penzias and Robert Wilson accidentally discovered the Cosmic Microwave Background (CMB) radiation left over from the Big Bang.  The Drake Equation was published for calculating the probability of finding extraterrestrial life and the SETI experiment started to attempt to make contact with them.
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-  X-ray astronomy was born.  Neutrinos were detected coming from the core of the Sun.  Quasars were discovered with redshifts of fantastic distances.  Pulsars were discovered.  But, nothing could compare with the CMB that was redshifted by a factor of 1,100 into the microwave wavelengths.  This tipped the consensus that the Big Bang explained the origin of the Universe.
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-  In 1970’s Mariner did a flyby of Mars, Mariner 10 reached Mercury, Voyager 1 and 2 reached Jupiter, Saturn, Uranus and Neptune.  Vikings 1 and 2 were Mars landers in 1976.
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-  1971 found rapid X-ray variability in Cygnus X-1 which was the first sign of a Blackhole.  It was not just the mathematics in Einstein’s equations.  Quasars were deemed the result of galactic Blackholes.
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-  Cosmic Gamma-ray bursts were detected while we were watching for nuclear weapons tests.
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-  A binary pulsar losing orbital energy proved the existence of gravity waves.
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-  1981 the Space Shuttle Columbia was launched.  Supernova 1987A exploded in the Large Magellanic Cloud, our neighboring dwarf galaxy.  1986 Halley’s comet did a fly-by.
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-  1990 the Hubble Space Telescope was launched.  3 years later a corrective lens was added by spacewalking astronauts.  1994 Comet Shoemaker-Levy 9 dove into Jupiter.  1995 an exoplanet was discovered in 51 Pegasi.  This launched a new field of astronomy and today 3,493 exoplanets have been identified.  Our conclusion:  “ Most stars have planets.”  1996 Comet Hyakutake whizzed by. 1997 Comet Hale-Bopp was in the western sky.
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-  2000’s saw Mars orbiters and rovers, Comet Tempel 1 visit, Messenger visits Mercury, Cassini visits Saturn.  Huygens descends on to Titan.  Pictures come back of water-powered geysers erupting off the surface of Enceladus.
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-  Kuiper Belt objects were discovered to be larger than the planet Pluto.  2006 Pluto and Ceres became “ Dwarf Planets”.  ( See Review #1910 for the story on Ceres).  2009 Kepler Space Telescope began the count for thousands of exoplanets based on the transits across the face of stars.  Discoveries started with detection using the radial-velocity wobbles of stars.
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-  WMAP plotted the afterglow of the Big Bang setting the age of the Universe at 13.8 billion years.  Then the ingredients of the Universe were calculated to be 4.9 % Normal Matter, 23% Dark Matter, and 69% Dark Energy.  The last two ingredients are still mysteries to be explained in this expanding Universe that is also expanding our knowledge of being here.
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-  The new decade of 2010 has a satellite Messenger orbiting Mercury, Dawn orbiting Vesta and Ceres, Curiosity rover crawling the slopes of Mars, Juno nearing Jupiter and Voyager 1 leaving the Solar System behind traveling past twice the distance of Pluto.
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-  2014, BECEP-2 provided precise patterns for the Cosmic Microwave Background.  New Horizon flew by Pluto.
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-  2016, LIGO detected gravitational waves from the merger of two Blackholes.
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-  2017, looking forward to what new discoveries astronomy has to offer. “ May you live in interesting times” has certainly not disappointed.  But, these are but pebbles on the beach with a whole sea of knowledge stretching out before us.
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-  I have individual Reviews on many of these events if you want to learn more about a particular one.  Available upon request.
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----  Comments appreciated and Pass it on to whomever is interested. ----
---   Some reviews are at:  --------------     http://jdetrick.blogspot.com -----
--  email feedback, corrections, request for copies or Index of all reviews
-  to:   -------    jamesdetrick@comcast.net  ------  “Jim Detrick”  -----------
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 -----   707-536-3272    ----------------   Tuesday, December 20, 2016  -----
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Small steps in astronomy

-  1907  -  Small steps in astronomy.  Each year small changes occur that are astronomical given time.  Here are a few small steps you may not have noticed.
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-----------------------------1907  -  Small steps in astronomy
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-  There are a lot of things happening in the Universe that you may not be noticing.  These are slow changes and our human senses are just to crude to measure.
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-  This past year the rotation of the Earth slowed down.  This slowing is caused by the friction of the tides and the constant tug of the orbiting Moon.  The time of a single rotation ( one day ) , has increased 14 nanoseconds this past year , 2016.  That might not sound like much ( 0.0000000014 seconds ), but in 4 million years from now we will loose our leap years.  By then the year will be exactly 365 days.
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-    This slowing of the Earth’s rotation has another effect in the Earth-Moon system.  There is the law of “ the Conservation of Angular Momentum”.  The Earth and the Moon both spin on their axis as the Moon revolves around the Earth.  To make Angular Momentum constant as the Earth spin slows down the Earth-Moon distance is increasing.  The Moon is leaving us by about 2 centimeters per year ( one inch ).
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-  Also, this past year the Sun got hotter.  This average temperature increase is not enough to cause ‘global warming’.  It amounts to an increased luminosity of 5 billionths of a percent each year ( 0.000,000,005% )  That doesn’t sound like  much either, but, that would mean the Sun has increased temperature and luminosity by 25% over the past 4 billion years.
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-  What is causing this is that the Sun is fusing fuel faster as it gets hotter.  Today it is loosing 10^17 kilograms of mass per year ( 100,000,000,000,000,000 kilograms according to E=mc^2).  In another 2 billion years the Sun will be hot enough to boil off  the Earth’s oceans.
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-  2 billion years after this happens the Sun will expand into a planetary nebula leaving a white dwarf cinder behind at the core.  Bigger stars will explode in to supernovae.  There is  1% to 2% chance that a supernova will go off in our Milky Way Galaxy this next year.  We can expect 2 to 7 supernova to be occurring in our Galaxy per century.  Most we can’t see, but, two have been seen with the naked eye,  Tycho’s Supernova in 1572  and Kepler’s Supernova in 1604.
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-  This past year stars have not only exploded and died, some new stars have formed.  In our region of the Orion Nebula a new star slightly smaller than our Sun is born each year  Star formation in our Galaxy is estimated to be 0.68 Solar Mass per year.  But, that is an average per year.  It could vary from 100 Solar Mass per century to 5 very low-mass stars per year.  Star formation is a gradual process taking millions of years.
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-  While all this is happening the overall Universe is expanding and cooling down.  Today the temperature is 2.725 Kelvin above absolute zero.  Absolute zero is the coldest temperature possible where all molecular activity ceases.
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-  This temperature is now measured in the Cosmic Microwave Background radiation after 13.8 billion years of cooling.  This background radiation continues to cool with continuing expansion separating the galaxies.  This year it went 200 picoKelvin cooler (2*10^-10 Kelvin ).  You probably didn’t notice.
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-  Another  thing happened with the expanding Universe.  We lost another 20,000 stars that expanded so far away their light will never reach us.  At that some 15 billion lightyears distance the galaxies are receding faster than the speed of light.  In fact, all the galaxies that are the Observable Universe today are only the remaining 3%.  The other 97% are so far distant their light will never get here.  Each year another 20,000 become unobservable in this way.
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-  These are small steps each year that become astronomical.  Tiny steps repeated can make a big difference in the long run.  A quote to live by.
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----  Comments appreciated and Pass it on to whomever is interested. ----
---   Some reviews are at:  --------------     http://jdetrick.blogspot.com -----
--  email feedback, corrections, request for copies or Index of all reviews
-  to:   -------    jamesdetrick@comcast.net  ------  “Jim Detrick”  -----------
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 -----   707-536-3272    ----------------   Saturday, December 17, 2016  -----
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From stars to Blackholes.

-  1908  -  Stars to Blackholes.  How stars form?  How they die and disappear?  How some become Neutron Stars and some become Blackholes?  How Blackholes merge to become the center of rotating galaxies?  How can all this happen?
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-----------------------------1908  -  Stars to Blackholes
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-  Looking up at the sky on a starry night we perceive we are looking at great distances to the stars.  We are.  But, we are also looking backwards in time.  That shining star might not be there today.  It may have gone supernova and now only reside as a dark cinder.
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-  Information and perception travel at the speed of light, 671,000,000 miles per hour.  Even our star, our Sun, is viewed 8 minutes backward in time.  And, so is gravity that is traveling at the same speed as light.  The more distant star in the night sky could be 10 lightyears away from us.  It takes 10 years for its light to reach us.  To us it is alive, but, that star could be a “ stellar ghost” today.  There is such a star at the center of the Crab Nebula, 6,523 lightyears away

-  Our largest stars die as Neutron Stars or,  as  Blackholes.  A star’s life is balanced by radioactive fusion and its own gravitational contraction, which depends on its size.  It lives in equilibrium surviving by the balancing act between these two forces.  The star is born fusing hydrogen into helium.  When the hydrogen at the core is used up helium begins to condense at the core.  The star shrinks, its core density increases, its core temperature rises.  The star the size of our Sun fuses elements heavier than helium, up to the element carbon.  Gravity created by the Sun-size stars is not strong enough to fuse elements heavier than carbon.  Fusion stops.  The star’s radiation dies.  It  becomes a stellar ghost.
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-  However,  for stars 7 times larger than our Sun the fusion to  heavier elements continues under the stronger pressure of gravity.    Past carbon and oxygen, past silicon, past heavier elements until fusion reaches the element iron.  Iron absorbs compression energy.  It does not release energy radiation to reach the next heavier element like the lighter elements do.  Without excess radiation energy to hold it up the star it collapses under gravity.  The inward free fall of layers of elements meet at the center and rebound outward as an exploding supernova.
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-  The outward explosion is so intense in temperature that the elements heavier than iron are created fusing all the way to the heaviest, Uranium.  All these new elements are blasted into the Cosmos as gas and dust to become seeds for new star formation.
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-  What happens next all depends on how much mass is left at the core of the supernova.  If it ends up as a  ball of  degenerative neutrons it becomes a Neutron Star, so dense a teaspoon would weight 10 million tons.  So concentrated in gravity pull the escape velocity required would be 40 % the speed of light.  If it is spinning at incredible velocities it is called a : Pulsar” with beams of radiation emitting from its poles.
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-  The spinning Neutron star generates an enormous magnetic field.  Electrons are accelerated into the magnetic poles.  These accelerating electric charges generate radio waves, X-rays, Gamma Rays.  If the magnetic pole is offset from the rotational pole the rotating beam of escaping charged particles becomes a light house sweeping around many times per second.  What astronomers see as a beam sweeping by our region of the sky, it is a “pulsar”.
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-  If the star’s core has a still greater  mass it does not stop at a Neutron Star; it continues to be crushed into a Blackhole where the escape velocity becomes over 100% the speed of light.  Light can not escape.  Its gravity warps space-time back onto itself.  It condenses to a point of infinite density.
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-  These massive stars are larger than 18 times Solar Mass.  Inside the Event Horizon that surrounds the Blackhole no information escapes.  It is even beyond the laws of physics.  We really don’t know what happens beyond the Event Horizon inside the Blackhole.
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-  The supernova that blasted elements away from the core forms molecular clouds in space to become stellar nurseries to form new stars, new planetary formations.  The accretion disks of rotating dust and gas around a newly formed star coalesce into planets, asteroids, and comets.
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-  The debris of the exploding star is what our world, our life, is made of.  The “ stellar ghosts” are our ancestors.  They exist within us.  Thoughts to ponder when staring into the starry night sky.
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-  But, what happens to the Blackholes?  We are learning that there are massive Blackholes at the center of most every large galaxy.  There is a  massive Blackhole at the center of our Milky Way Galaxy.  We obviously can not see it, but, we can see stars  that are orbiting some large center of mass.  A particular star orbiting with a period of 15.2 years, 11.18 billion miles radius, about a center mass must be held by a mass of 4.1 million Solar Mass, 9.04 * 10^33 tons.  The radius of the center mass must be less than 120 Astronomical Units (AU) in diameter, otherwise this star would crash into it.
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-  Similar massive Blackholes have been calculated to be at the centers of the Andromeda Galaxy ( M31), the elliptical galaxy ( M32), the spiral galaxy ( NGC4395).  Likely these super massive Blackholes are at the heart of all the large galaxies?
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-  Could these massive gravity pits be the result of merging smaller, stellar Blackholes?  Or, could these massive objects have formed in the primordial Big Bang era?  Or, are these giants remnants of several massive stars exploding and concentrating as accretion  matter at galactic centers?  We don’t know.
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-  Besides rotating stars about galactic centers  there are accretion disks of gas and dust gradually  feeding these center gravity pits.  The compression, collision, and speed of rotating, in falling, material reaches temperatures of millions of degrees Kelvin, generating bright radiation in electromagnetic energy.  These dynamos create powerful magnetic jets above and below the Blackhole reaching relativistic speeds extending out hundreds of thousands of lightyears.  These are called “ Quasars”.
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-  Super massive Blackholes have lower average density because their volume is directly proportional to the cube of their radius:
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-------------------------------  V  =  4/3 pi  r^3
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-  And, the minimum density is inversely proportional to the square of the mass:
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---------------------------  Density  =  mass  /  Volume
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-  The result being the tidal forces in the vicinity of the Event Horizon are significantly weaker for massive Blackholes.
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-  The diameter, or rather the radius, of the Event Horizon is 3 times the mass of the Blackhole:
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----------------------------  Radius  =  3 * mass
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-  Gamma Ray bursts have been detected leaving the Event Horizon.  One such burst was detected March 28, 2011, at the center of a galaxy 3.8 billion lightyears away.  X-ray detections followed.  The duration of the X-ray flares gave an indication of the size , or diameter, of the Blackhole accretion disk.
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-  Three X-ray flares had an average duration of 8 hours.  The flares traveling at the speed of light would travel a distance of 8.6 billion kilometers.
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--------------------------   Distance  =  speed  * time
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---------------------------  Distance  =  ( 300,000 kilometers / sec)  *  (8 hours)  *  ( 3,600 seconds / hour)
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---------------------------  Distance  =  8.6 billion kilometers
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-  The radius of the Blackhole is estimated to be 100 times smaller due to the measured “ beaming effect” of the flares.  So, the Blackhole radius is 43 million kilometers.
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---------------------------  Radius  =  3 * mass
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--------------------------  Mass of the Blackhole =  14 million Solar Mass
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-  This is about 3 times larger than the Blackhole measured at the center of the Milky Way Galaxy, which is 4.1 million Solar Mass.
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-  I have several other reviews on “ Blackholes”  if you want to learn more.
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----  Comments appreciated and Pass it on to whomever is interested. ----
---   Some reviews are at:  --------------     http://jdetrick.blogspot.com -----
--  email feedback, corrections, request for copies or Index of all reviews
-  to:   -------    jamesdetrick@comcast.net  ------  “Jim Detrick”  -----------
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 -----   707-536-3272    ----------------   Tuesday, December 13, 2016  -----
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A century of astronomy:

-  1906  -  A century of astronomy, hundreds of small steps for man, several giant leaps for mankind.  Albert Einstein started it at beginning of the century.  The space program follows for 100 years:
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---------------------1906  -  A Century of Astronomy.
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-  A century of astronomy.  It begins with Albert Einstein and physics in 1905 when Einstein introduced the idea of light being “ photons”, little bundles of energy.  He used this idea to describe the “ photoelectric effect”.  Later that year he outlined the ideas behind “ Special Relativity”.
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-  In 1906 Clyde Tombaugh discovered the planet Pluto.  It was not until 1909 that Karl Boblin first proposed that the Sun was NOT the center of the Milky Way Galaxy.
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-  1910, April 20, Halley’s comet had its closest approach at 14 million miles.  It will return July 28, 2061.  I’ll miss it.  In 1916 Karl Schwarzschild uses General Relativity to derive the size of the “Event Horizon” of a non-rotating Blackhole.
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-  November, 1915, Einstein adds gravity to his equations for General Relativity, as the curvature of space-time.    1923 - Edwin Hubble discovers a variable star and calculates the distance to discover the Andromeda Galaxy.
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-  In 1927  Georges Lemaitre proposes the expanding Universe from a single- point.  In 1948 the idea became known as the Big Bang.  In 1925 a doctoral thesis proposes that stars are made of hydrogen and helium.  In 1926  Goddard launches the 1st liquid fuel rocket.  In 1929  Hubble uses “ Redshifts” to explain an expanding Universe.  The more distant the galaxy the faster it is receding due to the expanding space.  Today the Hubble Constant of Expansion is calculated to be 70 kilometers per second per mega parsec., or 47,000 miles per hour per million lightyears distance.
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-  In 1931 the electron microscope is invented.  In 1933 Karl Jansky uses his home-made radio telescope to conclude that radio signals were originating at the center of the Milky Way Galaxy.
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-  In 1932 the neutron is discovered.  And, deuterium is discovered to contain one proton and one neutron  And, Carl Anderson discovers the “ positron”, an electron anti-matter.  Carbon Dioxide is discovered in Venus’ atmosphere.  Methane is discovered in Jupiter’s atmosphere.  In 1933 Fritz Zwicky proposes Dark Matter is holding galaxies together.  In 1934 he proposes a supernova would leave behind a Neutron Star.
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-  In 1935 the first radar experiments.  In 1936  33,342 stars were catalogued with their characteristics.  In 1938  Hans Bethe demonstrates how stars generate energy through nuclear fusion.  1939 - Bill Hewlett and Dave Packard start their company.  In 1941 from 14 supernovae observations Type I and Type II are defined.   Later Type 1a becomes the “standard candle” for distance measurements.  In 1942  Enrico Fermi achieves the first sustained nuclear reaction.
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-  In 1944 discovery of atmosphere on Saturn’s largest moon, Titan.  1946 - bounces radio signals off the Moon.  The ENIAC electronic computer operational.  The first radio interferometer is built.
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-  1947 - Bell X-1 plane breaks the sound barrier.  Bell labs invents the transistor.  1948 - the Cosmic Microwave Background radiation (CMB) is discovered.  1949 - Cape Canaveral, Florida is built for rocket testing.  Big Bang nucleosynthesis proposed as how elements were created.
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-  1950 - The Oort Cloud thought to contain a trillion comets between 20,000 AU and 100,000 AU away.  Comets are proposed to be “ dirty snowballs”.  In 1986 they are proposed to also have rocky cores.  In 1951 the Kuiper Belt of comets are found between 30 AU and 55 AU.
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-  1952 - Cepheid Variable stars proposed as another “ standard candle “ to measure astronomical distances.  Hydrogen bomb is detonated.  The sub-atomic neutrino is detected.  1953 - measuring radioactive decay of meteorite deduces the age of the Earth to be 4.55 billion years.   1954 - Metric System established.  1955 - the anti-proton discovered.  Atomic clock invented using Cesium - 133 atoms.  Electron synchrotron radiation discovered.  1956 - anti-neutrino discovered.
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-  1957 - nucleosynthesis in the stars proposed on how the 97 elements heavier than hydrogen and helium and lithium were created.  1957 - Fortran used in computers for scientific computing.  Sputnik 2 launches a dog into space.  1958 - NASA is created.  Explorer satellite defines the Van Allen Radiation Belts circling Earth.
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-  1959 - U.S. launches the first weather satellite.  And, puts rhesus monkey into sub-orbit returning safely to Earth.  1961 - Yuri Gagarin becomes 1st human in sub-orbit.  Alan Shepard next in a 15 minute sub-orbit.
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-  1962 - Mariner2 in Venus fly-by.  Muons detected measured to have time-dilation according to equations in Special Relativity.  1963 - Quasar redshift finds galaxy moving away at 16% the speed of light.
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-  1964 - Discovery of the Cosmic Microwave Background radiation.  Sub-atomic quarks were discovered as components of protons and neutrons.  Ranger 7 takes 4,300 close-up pictures of the Moon.  Density waves explain Milky Way’s spiral arms.  Higgs Boson proposed to explain how particles obtain mass.  Gemini 3 astronauts circle the Earth.  Mariner 4 does Mars fly-by.
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-  1966 - Soviet Union lands Luna 9 probe on the Moon.  Their Venera 3 crashes into Venus.  Leonid comets shower at 150,000 meteors per hour.  Soviet’s Luna 10 orbits the Moon.  NASA Surveyor 1 lands on the Moon.  1967 - Gamma Ray Bursts first discovered.
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-  1967 - Electroweak Force proposed to combine electromagnetic and weak nuclear forces.  Soviet Union Venera 4 descends through Venus’ atmosphere.  1968  Apollo 8 orbit’s the Moon.  1969 to 1972 twelve American astronauts walk on the Moon.  The Murchison meteorite that falls on Australia contains organic compounds and amino acids originating in space.
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-  1971 - Soviet Mars 3 makes a soft-landing.  Mariner 9 orbits Mars.  1972 - Pioneer 10 launched for Jupiter.  1973 Skylab orbits Earth.  Type 1a supernovae defined as “Standard Candles”.  1973 - Pioneer 10 fly-by of Jupiter.
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-  1974 -  “Quasar” discovered to be 900 million lightyears from Earth.  The first “Pulsar” is discovered.  Sagittarius A* measured to be a Blackhole of 4.3 million Solar Mass at center of our Galaxy.  Pioneer 11 does Jupiter fly-by.
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1975 - Soviet Venera 9 lands on Venus.  1976 - Viking I and II land on Mars.  1977 - rings discovered orbiting Uranus.  1978 - Pluto’s moon Charon discovered.  Pioneer 11 reaches Saturn.  1979 - gravitational lensing of Quasars confirms Einstein’s calculation in theory of General of Relativity.
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-  1980 - Asteroid suggested to be cause of extinction of dinosaurs.  Voyager I reaches Saturn.  Alan Guth ‘s  Inflation Theory solves “ Horizon Problem” and “ Flatness Problem” in cosmology of the Universe.
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-  1983 - Sally Ride 1st American women in space.  1986 - Voyager 2 passes Uranus.  1988 the Einstein Ring observed due to gravitational lensing.  Deuterium discovered on Mars.  Extra-solar planet evidence found around star, Alrai.  But, data is poor quality.  MIR Russian Space Station in orbit.  Supernova 1987a exploded 168,000 years ago.  Its light just reaches Earth.  Voyager 2 reaches Neptune.
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-  1989 - COBE satellite measures Cosmic Microwave Background radiation.  Voyager 2 passes Neptune.  1990 - Hubble Telescope in orbit.  1993 - Endeavour astronauts correct Hubble telescope’s vision problem.    1990 - Magellan spacecraft orbits Venus.  CERN introduces the first Web page.  1991 - Yucatan impact crater identified as asteroid impact.  First exoplanets discovered outside our Solar System.
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-  1992 - seeds of galaxies discovered in Cosmic Microwave Background radiation.  First Kuiper Belt object beyond Pluto discovered.  1994 - Comet Shoemaker-Levy smashes into Jupiter.  Dwarf galaxy discovered just 50,000 lightyears away.  First Brown Dwarf object discovered bigger than a planet but too small to be a star.
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-  1995 - Closest exoplanet discovered orbiting 51 Pegasi.  Galileo spacecraft orbits Jupiter.  Science creates element number 112, called Copernicium.  10 meter telescope on Mauna Kea, Hawaii.  GPS becomes operational using 32 satellites.  Today’s accuracy to within 14 nanoseconds.
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-  1997 - Mars Pathfinder lands.  Contact not lost until 2006.  Blackhole discovered in galaxy M84.  1998 - water- ice discovered at the poles on the Moon.  Neutrinos have mass.  Liquid water lies under the ice of Jupiter’s moon Europa.  Quantum teleportation demonstrated.
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-  1998  -  First components of International Space Station in orbit.  Since 2000 the home for over 200 astronauts.  1999 - Chandra X-ray Observatory deployed.  Type 1a supernovae in distant galaxies peg the Universe expansion rate acceleration.  Dark Energy accounts for 69% of composition of the Universe.  Dark Matter 29%.
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-  2000 - 11 new moons discovered around Saturn.  10 new moons discovered around Jupiter.  2001 -  11 more moons discovered around Jupiter.  NESAR spacecraft lands on asteroid.  WMAP analysis of CMB pegs Universe at 13.77 billion years old expanding at 69.3 kilometers per second per mega parsec, that is 47,000 miles per hour per million lightyears.
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-   2003 - Hubble Ultra Deep Field image of 10,000 distant galaxies back to 400 million years after Big Bang.  Dwarf Planet Sedna discovered.  Voyager I sends data back from edge of Sun’s heliosheath.  Twin Rovers explore Mars, discover recent water flows and frost.
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-  2004 - Cassini- Huygens spacecraft orbits Saturn.  2005 - Deep Impact spacecraft smashes into comet.  Finds density of comet to be like talcum powder.  Dwarf Planet Haumea discovered in the Kuiper Belt.  Mars Reconnaissance orbits Mars.  Huygens probe lands on Saturn’s moon Titan.  Sends data for 90 minutes.  Dwarf Planets Eris and Makemake discovered.  Nix and Hydra moons discovered orbiting Pluto.
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-  2006 - Pluto demoted to a Dwarf Planet.  2007 - Phoenix Mars lander.  1999 mission returns “ Stardust” from comet to Utah desert with samples.  Amino acid and glycine found in samples.  2009 - Kepler Space Telescope hunts for exoplanets.  Over 2,200 planets discovered with an additional 4,500 candidates still under investigation.
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-  2011 - Messenger spacecraft orbits Mercury.  Dawn spacecraft orbits asteroid Vesta.
2013 - Planck satellite provides data on CMB.  2014  - Rosetta spacecraft arrives at comet.  New Horizon passes Pluto.  Dawn orbits Dwarf Planet Ceres.  2016 - gravitational waves detected.  Planet 9 may have been discovered?  Higgs Boson discovery probably pre-mature.  Need more data.  Stay tuned, an announcement will be made shortly.
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-  (1)  From Astronomy magazine September, 2016 issue.
-  (2)  Other reviews available on this subject:
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-  #1742  -   #1743  -  #1744  -  # 1745  Astronomy facts.  Hundreds of interesting facts about astronomy.
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-  #936  -  “What the heck is goin on round here?”  Examples of some of the strangest astronomy.
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-  #902  -  Astronomical directions.  How measurements are made in astronomy.
-
-  #1458  -  Astronomy helps society.  Other inventions that came from astronomy work.
-
-  #641  -  To be a good writer you need to be more like an astronomer and less like a physicist.
-
-  --------------------------------------------------------------------------------------
----  Comments appreciated and Pass it on to whomever is interested. ----
---   Some reviews are at:  --------------     http://jdetrick.blogspot.com -----
--  email feedback, corrections, request for copies or Index of all reviews
-  to:   -------    jamesdetrick@comcast.net  ------  “Jim Detrick”  -----------
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 -----   707-536-3272    ----------------   Monday, December 12, 2016  -----
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Asteroids that hit the Earth

-  1825  -  Asteroids responsible for evolution on Earth?  How many times has Earth been hit by a large asteroid?  What is the likelihood of another hit?  What is Congress and NASA doing about this potential danger?  The math to calculate the energy of an impact.
-
-

-
-----------------  1825  -  Asteroids responsible for evolution on Earth?
-
-  School kids study dinosaurs with wide-eyed fascination.  They really did live here.  Theme parks and museums show off the bones of the extinct giants.  Kids learn that the dinosaurs were killed off by an asteroid impact.  The 6-mile wide asteroid impact created the end of the Cretaceous Period 65 million years ago in the evolution of life on our planet.  See footnote (1) for the energy calculation.
-
-  There was another period, the Permian-Triassic Period, 250 million years ago that may have suffered the same asteroid fate.
-
-  Life on Earth began 3,500 million years ago.  There must have been many more asteroid impacts during our evolution.  There is evidence that 15 enormous asteroid strikes have occurred between 1,700 and 3,500 million years ago.  4 have occurred at the end of the Achaean Period, 2,500 million years ago.
-
-  The first living microbes appeared on Earth 3,500 million years ago.  Coincident with that period was a buildup of oxygen in the atmosphere and the beginning of multi-cellular organisms.
-
-  Most of Earth was covered with ocean during the Achaean Period.  Asteroid scars would reside on the ocean floor which would have been recycled into the Earth’s interior.
-
-  The oldest rock we can find are the Barbeton Greenstones in South Africa from the Achaean crust and the Pilbara Region in Western Australia.
-
-  Giant impacts melt rocks and create distinctive glass spherules ( little beads that look like caviar).  Finding the element Iridium along side of the spherules allows radioactive dating.
-
-  Compiled evidence suggests the Earth was pelted by asteroids 30 miles wide.  The impacts would have boiled the oceans, cooked the little dry land, and created a dust cloud locking the Sun for years.  Some of these impacts would have fractured the Earth’s crust and changed the plate tectonics.
-
-  Now the real mystery:
-
-  Did these ancient extinctions create the rise of photosynthesis?
-
-   Did they result in the emergence of eukaryotic cells, or predatory microbes?
-
-  See Review #1823  for a possible explanation of why Earth gets pelted wit asteroids every 33 million years, as we pass through the disk of the Milky Way Galaxy.
-
-  In 2010 NASA got the congressional order to identify 90% of the Near Earth Orbiting  NEO asteroids with a diameter of 1 kilometer ( 0.62miles)  or larger.
-
-  In 2013 an 8 meter ( 59 feet) rock exploded in the atmosphere over Chelyabinsk, Russia injuring 1,600 people , mostly those looking out glass windows when they first saw the flash.  The shock wave that followed the flash caused over $30 million  in damage.
-
-  See Footnote (1) to learn the damage level of the asteroid Chicxulub that struck the Yucatan creating a crater 62 miles in diameter.
-
-  There are 1 million asteroids larger than 1 kilometer (0.62 miles), mostly orbiting between Mars and Jupiter.  8,000 are cataloged.  Asteroids only reflect light.  Using a spectrometer astronomers can determine the composition of the asteroid from this reflected light.
-
---------------------  There are 3 classifications:
-
--------------------  (1)  carbonaceous
-
--------------------  (2)  silicate  ( olivine)
-
--------------------  (3)  metallic
-
-  Comets are icy because they formed in the outer Solar System.
-
-  Asteroids are rocky because they formed in the inner Solar System, or are comets that migrated into the inner Solar System and the Sun evaporated their ice.
-
-  There are 500 Earth-Crossing Asteroids (NEOs).  All will impact over the next 25,000,000 years.  On average this calculates to an impact every 50,000 years.
-
-  The Congress ordered NEO search is currently using 3 telescopes , all ground based,   and a single satellite with wide-field infrared survey explorer.  This satellite detects the thermal glow as objects get heated by the Sun.  NASA’s funding to do this
NEO search is $40 million this year.
-
-  That would be a cheap price tag if NASA could predict an asteroid impact in time for space jockeys to go out there and do something about it.  ( This idea would make a great movie).
-
-  A 2017 launch of $500 million would send NEOCAM spacecraft on the mission to characterize the orbits, shapes, composition and spin rates of NEO’s.  This new data would help science trace out the history of the Solar System as well as select targets for robotic deep-space missions to intercept asteroids and redirect them.
-
-  Lets hope such a mission to redirect an asteroid is not too late or under funded to miss our chance.  The dinosaurs had no astronauts.
-
---------------------------------------------------------------------------------------
-
-  (1)  The Chicxulub crater in Yucatan, Mexico is 100 kilometers across ( 62 miles0.  The asteroid impact was 17,500 miles across.
-
-  The density of the asteroid rock was 2,700 kilograms / meter^3.  (The density of water is 1,000 kg/m^3).
-
-  The volume of the asteroid is 2.81*10^12 m^3.
-
------------------------  Mass  =  Density  *  Volume
-
------------------------  m  =  2.81*10^12   *  2.7*10^3 kg
-
------------------------  m  =  7.6*10^15  kg
-
----------------------  Kinetic Energy  =  ½  Mass *  ( velocity)^2
-
----------------------  velocity  =  45,000 miles / hour,  (  20,000 meters / second)
-
----------------------  K E  =  ½  * 7.6*10^15  *  4*10^8  m^2/sec^2
-
----------------------  K E  =  15.2 *10^23  kg m^2 /sec^2
-
---------------------  One ton of TNT  =  4.2 *10^9  Joules of energy
-
---------------------  Impact  =  36,000,000,000,000  tons of TNT
-
---------------------  Magnitude 7 Earthquake  =  10^15 joules
-
---------------------  Impact  =  1,520,000,000 Earthquakes at one time.
-
----------------------Hiroshima atomic bomb  =  8.4 *10^13
-
----------------------Russia’s1961 atomic bomb  =  1.8 * 10*10
-
--------------------  Impact  =  1,500,000 atomic bombs all at once.

-  (2)  Request these Reviews to learn more:
-
-  #1769  -  The mass of all known asteroids is less than the mass of the Moon.  Nearly 500 NEO asteroids have been discovered.
-
-  #1580  -  Asteroids - the bricks that build Solar Systems.  Most asteroids are not spherical because they are not massive enough for the necessary gravity.
-
-  #1554  -  Asteroids and meteorites are fossils with stories.
-
-  #1429  -  There is an asteroid heading right towards us.
-
-  #1375  -  There is an asteroid following us around the Sun.
-
-  #1309  -  Vesta and Ceres asteroids get a spacecraft visitor.
-
-  #1296  -  When as asteroid hit Manson, Iowa.
-
-  and more……….
-
-  --------------------------------------------------------------------------------------
-----------------  RSVP, Pass it on to whomever is interested. ----------------
---   Some reviews are at:  --------------     http://jdetrick.blogspot.com -----
--  email comments, corrections, request for copies or Index of all reviews
-  to:   -------    jamesdetrick@comcast.net  ------  “Jim Detrick”  -----------
-  https://plus.google.com/u/0/  -- www.facebook.com  -- www.twitter.com
 -----   707-536-3272    ----------------------   Tuesday, December 6, 2016  -----
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Mars Explorations

-  1905  -  Mars Explorations.  Over 40 missions have been sent to Mars.  20 were successful in studying the Red Planet.  This year the missions will get closer to the answer” “ Is there evidence of life on Mars? “
-
-

-
-----------------------------1905  -  Mars Explorations
-
-  “ExoMars is a satellite orbiting Mars since last month, October 2016.  Much of the press has been about the lander, Schiaparelli, that had an altitude indicator malfunction and crashed on the surface.  However, the satellite in orbit is still working fine.
-
-  The satellite is currently taking pictures in 3D and color from as low as 146 miles elevation.  The resolution at this altitude is down to 20 meters across.  The orbit is elliptical extending out to 62,000 miles completing its orbit every 4.2 days.  The plan is to take 12 to 20 images of selected targets each day.
-
-  In addition to photos, the orbiting satellite carries 4 scientific instruments to measure methane, carbon dioxide, and evidence of water.
-
-  Detecting methane may provide evidence of some biological activity although it could also mean geological activity such as hydrothermal vents that can also produce methane.
-
-  One of the twenty successful missions to Mars has been the “Curiosity Rover”  that has been exploring the surface of Mars for the last 4 years.  Its most impressive discovery was uncovering evidence of warm, flowing water on the surface of Mars.  The Rover must avoid these areas to prevent contamination.  The areas are dark streaks that appear, fade, and re-appear.  A total of 452 of these areas have been observed appearing in the warmest times of the year.
-
-  The water source is believed to be salt water that is frozen about a meter below the surface.
-
-  Curiosity Rover will avoid these areas as it climbs a mountainside to study sedimentary deposits.  The goal is to learn from sediments how Mar’s environment has changed over the last 3 billion years.  The geology of Mount Sharp has already shown evidence of a series of lakes along its basin.
-
-  The whole study must remain cautious because the Rover was only partially sterilized before launch and we do not  know how long Earth microbes could survive in Mar’s atmosphere , or how far they could spread.
-
-  The next mission to Mars will be aimed at discovering Mar’s microbial  life.  It is imperative that these earlier missions do not contaminate this investigation.
-
-  There are currently 7 active missions studying Mars.  The most recent arrival ExoMars 2016 will test for traces of methane in the atmosphere.  The hope is to determine if the methane is from geological, chemical, or biological processes?  ( See Footnote 1).  This mission will also test for subsurface ice deposits.
-
-  May 2018 “ Insight Lander” is designed to study the density and structure of the core, mantle ,and crust of Mars.
-
-  In 2020 another Rover mission will collect and analyze soil for chemical signs of past life.  It will use a plutonium-fueled nuclear radioactive thermal generator as a power source for an arm, camera, and seven other scientific instruments.
-
-  Several more missions from several nations are in the planning stage as well.  This includes Elon Musk’s plans for a planned manned mission in 2025.
-
-  The mission would require a lot of material sent in advance of the crew.  On year two the crew would launch taking 210 days to reach Mars.  Spend 496 days on the planet and return taking another 210 days.  The whole mission duration would take 6 years.  It would cost more than $450 billion dollars, according to plan.
-
----------------------------------------------------------------------------------------
-  Footnote (1)  -  Methane as a gas gets broken down within 400 years by the effects of ultraviolet light.  It must be replenished which could come from microbes which would be our first indication of life on Mars.  But, a hot water reaction to the mineral olivine could be a source of methane.  Also, the Sun’s ultraviolet rays breaking up micro-meteoroids on the dusty surface could produce methane.  To tell the differences the ratios of carbon-13 and carbon-12 will be used.
-
-  Footnote (2)  -  Mars has 2 moons, Phobos, and Deimos.  Deimos is 7.8 miles in diameter ( town size ).  Phobos is 13.8 miles in diameter ( city size ).  Deimos orbits at 14,580 miles elevation.  Phobos orbits at a mere 5,827 miles above the surface taking only 7 hours and 39.2 minutes to complete each orbit.
-
-  The tidal forces and rotational stresses are pulling Phobos apart.  Its self-gravity and tensile strength are holding it together.  Its orbit is descending 2 centimeters per year.  This inward spiral although small will lead to its destruction in 25 million years from now.
-
-  Phobos’ composition is porous , like a rubble pile.  Its density is only 1.9 grams per cubic centimeter ( our Moon is 3.3 gm/cc).  Like most meteorites its composition is carbonaceous chrondites, magnetite, olivine crystals, silicates and complex organic molecules, such as amino acids.
-
-  When Phobos reaches 3,400 miles above the surface it will completely disintegrate spreading into a ring circling Mars.
-
-  There several other reviews on Mars available upon request.
-
-  --------------------------------------------------------------------------------------
----  Comments appreciated and Pass it on to whomever is interested. ----
---   Some reviews are at:  --------------     http://jdetrick.blogspot.com -----
--  email feedback, corrections, request for copies or Index of all reviews
-  to:   -------    jamesdetrick@comcast.net  ------  “Jim Detrick”  -----------
-  https://plus.google.com/u/0/  -- www.facebook.com  -- www.twitter.com
 -----   707-536-3272    ----------------   Saturday, December 3, 2016  -----
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Studying the speed of light.

-  1904  -  Studying the speed of light has lead to many new discoveries along the way.  And, even to some new mysteries yet to be discovered, like Dark Energy and Dark Matter.  It all started in the 1600’s with Ole Romer’s ingenious calculation.
-
-

-
-----------------------------1904  -  Studying the speed of light.
-
-  Ole Romer in 1676 used the moon, Io, of Jupiter whose orbit worked like a clock.  One orbit took 1.769 days, or 42,456 hours, or 2,547,36 minutes.
-
-  Then, he used the orbit of the Earth about the Sun.  The distance from the Earth to the Sun is 93,000,000 miles.  Therefore, the diameter of a complete orbit is 186,000,000 miles.
-
-  Using the closest orbit to start the clock, then waiting six months to arrive at the most distant orbit, Ole found that Io crossed the crest of Jupiter 22 minutes later, every year.  This meant it took light 22 minutes for light to cross the 186,000,000 mile additional distance.
-
---------------------  distance  =  rate  * time
-
---------------------  rate  =  speed of light  =  distance  / time
-
--------------------  speed of light  =  186 * 10^6  /  22  /  60
-
---------------------  speed of light =  507,272,272  miles per hour.
-
-  Ole’s very first calculation in 1676 was 76% of the best answer we have today.
-
---------------------  Speed of light =  676,616,692     mph
-
-  Christian Huygens  and Isaac Newton got their own calculations to come up with:
-
----------------------  speed of light = 492,126,000 miles per hour.
-
-  In the 1850’s scientists arrived at :
-
---------------------  speed of light =  704,635,000   mph
-
-  It was  about the time that physics was measuring electromagnetic charges and electrostatic charges , realized they traveled at the same speed, and that light must also be an electromagnetic wave.
-
-  In Einstein’s 1905 paper he proposed that the speed of light in a vacuum, measured by a non-accelerating observer, is the same, independent of the motion of the source or the observer.  He delivered a lecture using 3 symbols for mass, energy and the speed of light and later proved that mass and energy were the same thing.  Mass is simply concentrated energy according to :
-
--------------------------  E = mc^2
-
-------------------------- c =  being the speed of light in a vacuum.
-
-  The speed of light travels at different speeds due to the medium in which it is traveling.  It travels between atoms at its constant speed, but it is being absorbed and re-emitted by atoms as it moves through the medium making a “net” slower speed.
-
-  For example:  a light beam traveling through a glass of water:
-
------------------------  The speed in air is------------  186,222  miles per second
-
------------------------  The speed through glass  ---  124,275  mps
-
------------------------  The speed through water  ---  140,430  mps
-
-----------------------  Through glass -----------------  124.275  mps
-
------------------------  Through air  ------------------  186,222 mps
-
-  Einstein’s claim that the speed of light from a moving source is counterintuitive.  He maintained that the speed of light is always the same regardless of the initial reference frame.  In other words light speed does not get added to its  motion of a source in a medium.  Further, a moving body approaching the speed of light would appear to slow down from the frame of the observer.  The distance would shrink and the time would slow to keep the speed, the ratio,  a constant.
-
-  It was not until the 20th century  that measurements using laser interferometers and cavity resonators would more accurately measure the speed of light.  In 1972 the value became:
-
---------------------------  c  =  299,792,458   meters per second.
-
---------------------------  c  =  670,616,692   miles per hour.
-
-  The other consequence of the speed of light being a “ constant” is the unification of “space-time”.  In order for that to happen space and time become variables.
-
-  In the 1920’s  the speed of light was used to determine that the Universe was expanding.  And, the further away the galaxy was from us the faster it was receding.
-
-  This receding calculation was 68 kilometers per second per mega parsec distance away.  Put in other units:
-
------------------------  47,000 miles per hour per million lightyears distance.
-
-  In the 1990’s this acceleration was measured to even be increasing over the past 5 billion years.  That would mean the most distant galaxies are receding faster than the speed of light.
-
-  This does not mean that the galaxies are traveling that fast.  It simply says the volume of space between us is expanding that fast.  This realization has lead us to what is causing the accelerating expansion?  We don’t know?  We call it “ Dark Energy”.  It remains a “Dark Mystery”.  A driving force that we just can not explain.
-
-  In the meantime, we still think the speed of light is a constant:
-
------------------------  c  =  670,616,692   miles per hour
-
------------------------  c  = 186,282  miles per second,  in the vacuum of space.
-
----------------------------------------------------------------------------------------
-
-  Other reviews available on this subject:
-
-   #1845  Why is the sky blue?  It took 100 years to get the correct answer.
-
-  #1795  -  Just seeing light uses half your brain. This review lists #940, #934, #726, #648, #550, #36 and a dozen other reviews about light.
-
-  Light does not know time.
-
- The light that can be viewed through a telescope is 12,000,000, 000 years old and still ticking.
-
-  --------------------------------------------------------------------------------------
----  Comments appreciated and Pass it on to whomever is interested. ----
---   Some reviews are at:  --------------     http://jdetrick.blogspot.com -----
--  email feedback, corrections, request for copies or Index of all reviews
-  to:   -------    jamesdetrick@comcast.net  ------  “Jim Detrick”  -----------
-  https://plus.google.com/u/0/  -- www.facebook.com  -- www.twitter.com
 -----   707-536-3272    ----------------   Tuesday, October 4, 2016  -----
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Chemistry to biology

 Nanotechnology from Chemistry to Biology.  The computer technology is advancing into smaller and smaller architectures.  Where is the limit?  What are new alternatives that can extend past the limit?  Request Review 1846 if interested.

Juno’s mission arriving at Jupiter.

-  1903  -  Juno’s mission arriving at Jupiter.  The spacecraft has only 20 months to send data from 9 instruments before the intense radiation destroys the electronics.  What will we learn about the biggest planet and the evolution of our Solar System?
-
-

-
-----------------------------1903  -  Juno’s mission arriving at Jupiter
-
-  The spacecraft “ Juno” made its closest approach August 29, 2016 in the first fly-by of the planet Jupiter.  It was only 2,600 miles above the surface.  It will be days before all the data being collected will begin to be analyzed and months before science can comprehend the new things to be learned.
-
-  The measurements are being made on the gravitational and magnetic fields, on the deep winds on the surface, and on the planet’s composition.  The robotic probe is expected to continue its mission orbiting until February, 2018.  Juno was launched August 5, 2011.  Five years later it enters its orbit around this enormous gaseous planet after traveling 1.74 billion miles.
-
-  In order to get a boast of speed Juno had looped around Earth in a fly-by August 9, 2013.  Stealing angular momentum from Earth’s gravity it gained another 8,800 miles per hour, reaching the Jupiter system traveling 165,000 miles per hour.  ( See Review #1902 regarding the calculations using the Conservation of Angular Momentum ).
-
-  Juno becomes the fastest man-made object until it fires its engines for 30 minutes to put it into a 53.5 day orbit around Jupiter.  The orbit is highly elliptical between 3,100 miles and 1,170,000 miles from the surface.  A new orbit will eventually be reduced to 14 days allowing a total 37 orbits in its 20 month mission.
-
-  Juno carries nine instruments to explore the interior of the atmosphere.  To map the gravity and magnetic fields.  To track water in the atmosphere.  To take pictures of the swirling clouds, the polar region, and the auroras at the poles.
-
-  The data collected takes 48 minutes, 19 seconds to return to Earth, if all goes well.  Juno will be immersed in a strong and variable magnetic field and hazardous radiation.  To shield the instruments they are surrounded by a 400 pound titanium vault.  Titanium is radiation resistant.  It will need it.  The spacecraft must endure the equivalent of 100 million X-rays.  The camera will have image resolution at 1.8 miles per pixel at its closest approach.  (  Visit  www.missionjuno.swri.edu/junocam ).
-
-  Juno is powered by a trio of 29 feet solar arrays that output 500 watts.  These solar arrays will receive only 4% as much sunlight as they would orbiting Earth.
-
-  The instruments will map the deep winds that reach speeds of 384 miles per hour.  The atmosphere consists of mostly hydrogen and helium, about the same ratios as our Sun.  The instruments hope to measure the global water and ammonia that are in the  atmosphere.
-
-  The magnetic field to be  mapped is 1,000 times stronger that Earth’s.    This map is created orbiting over the poles.  It is designed to help science learn the origin of Jupiter’s magnetism and the nature of the planet’s core.  Juno’s microwave radiometer will profile temperatures to a dept of 220 miles where pressures are 200 times Earth’s atmospheric pressure.  This radiometer is only expected to survive for 11 orbits.
-
-  Measurements will be made of the ratio of oxygen to hydrogen and of the amount of water that exists in the atmosphere.  Deep in the atmosphere the gravity is so intense that electrons are stripped form the hydrogen atoms and plasma becomes electrically conductive liquid metallic hydrogen.  Science thinks this shell of metallic hydrogen might be the source of Jupiter’s magnetic field.
-
-  The magnetic field generates powerful auroras at the cloud tops that is 1,000 times stronger than Earth’s auroras.
-
-  Juno’s orbit crosses the paths of moons, Europa, Ganymede, and Callisto making it imperative that there is never an impact to cause pollution.  Therefore in 2018 Juno will be sent into Jupiter’s atmosphere to disappear for good.
-
-  The end of Juno’s mission, February, 2018.  But, the data will be analyzed for years to follow.  Stay tuned, an announcement will be made shortly.
-
----------------------------------------------------------------------------------------
-
-  Other reviews available on this subject:
-
-  #1880  -  More about the Juno mission
-
-  Lists 4 other reviews about Jupiter’s moons and rings.
-
-  --------------------------------------------------------------------------------------
----  Comments appreciated and Pass it on to whomever is interested. ----
---   Some reviews are at:  --------------     http://jdetrick.blogspot.com -----
--  email feedback, corrections, request for copies or Index of all reviews
-  to:   -------    jamesdetrick@comcast.net  ------  “Jim Detrick”  -----------
-  https://plus.google.com/u/0/  -- www.facebook.com  -- www.twitter.com
 -----   707-536-3272    ----------------   Monday, August 29, 2016  -----
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The Moon and Angular Momentum.

-  1902  -  How the Moon uses the Conservation of Angular Momentum.  The math involved.
-
-

-
-----------------------------1902  -  The Moon and Angular Momentum.
-
-  If the moon’s orbit takes longer than a day the planet’s rotation slows down and the moon drifts further away to compensate due to the Conservation of Angular Momentum.   Our Moon is drifting away at 1 ½ inches per year.
-
-  The orbital angular momentum of the Moon is 29 *10^33        kg^2 / second.
-
-  The rotational angular momentum of the Earth is 7.1 * 10^33       kg^2 / second .
-
-  The Moon’s orbit has 4 times the momentum as Earth’s rotation momentum decreasing the Earth’s rotation rate by 23 micro-seconds per year.  This effect results in the Earth-Moon distance expanding by 1 ½ inches per year in order to restore the Conservation of Energy, the Conservation of Angular Momentum.
-
-----------------------  Momentum  =  mass  *  velocity  =  mass  * distance / time
-
---------------------  Angular Momentum  =  mass  * radius ^2  * angular velocity.
-
-  This formula requires that we define the composition of the distance, or radius of the rotation.  In this case we define it as a  “uniform sphere”.   Angular Velocity is in radians / second , or degrees of rotation per second.
-
-  To calculate the Angular Momentum of the spinning Earth:
-
-----------------------  Mass  =  6 * 10^24 kilograms
-
----------------------  Radius^2  =  (  6.4*10^6 meters )^2
-
----------------------  Angular Velocity  =  2*pi radians  /  24 hours
-
----------------  Angular Velocity  =  2*pi radians  /  86,400 seconds  =  7.3 *10^-5 radians per second
-
-  The rotational inertia of a uniform sphere is:
-
-----------------------  Inertia  -  2/5 mass * radius^2
-
------------------------  I  =  2/5 m*r^2
-
-  Of course, the Earth is not a uniform sphere so this calculation is only an approximation.  Our calculated value will be 20% too high.  But here it is:




-
------------  Angular Momentum =  0.4 * (6 * 10^24) * ( 6.4*10^6)^2 * ( 7.3*10^-5)
-
------------  Angular Momentum =  7.3 * 10^33     kilograms * meters^2 / second.
-
-  The more accurate calculation for the Earth’s rotational angular momentum is reduced by 20%:
-
-------------  Angular Momentum =  7.1 * 10^33       kilograms * meters^2 / second.
-
-  We now make the same calculation for the Moon’s rotational angular momentum;
-
---------------------  Momentum  =    2/5 *  m *  r^2  * w
-
----------------------  Mass of the Moon  =  m  =    7.35*10^22    kilograms
-
---------------------  Radius  =  r  =  1.74*10^6  meters
-
--------------------- Angular Velocity  =  w  =  2*pi  /  27 days
-
--------------------- Angular Velocity  =  w  =  6.24  radians  /  2,332,800  seconds
-
--------------------  w  =  2.7*10^-6  radians per second
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-------------------  Momentum  =  0.4 * ( 7.35*10^22 ) * (1.74*10^6 )^2  *  ( 2.7*10^-6 )
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--------------------  Rotational Momentum  =  2.4 *10^29    kg * m^2 /sec
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-  Earth - Moon rotational momentum ratio  =  7.1 *10^33  /  2.4 * 10^29  =  30,000.  So, the Moon’s rotational momentum is not much of a factor for the Earth-Moon system, 1/30,000th is very small.  Let’s try calculating the Moon’s orbital momentum.
-
---------------------  Orbital Momentum  =  m * r^2 * w
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---------------------  m  =  7.35 * 10^22     kilograms
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---------------------  r  =  385,000 kilometers    =    3.85 *10^8 meters
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----------------------  w  =  2.7*10^-6  radians per second.  It is the same because the Moon makes only one rotation with each orbit around the Earth.
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-----------  Orbital Momentum  =  ( 7.35 * 10^22 ) * ( 3.85 *10^8 )^2  *  (  2.7*10^-6 )
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-----------  Orbital Momentum  =  29.4 *10^33   kg*m^2/sec
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-  The Moon’s orbital angular momentum is 4 times greater than the Earth’s rotational momentum.  The Earth’s rotation momentum is decreasing , loosing 23 micro-seconds (23*10^-6  sec)  per year.  The Moon’s orbital angular momentum is increasing to compensate and maintaining the Conservation of Angular Momentum a constant.  The Earth-Moon distance is increasing 1 ½ inches per year.
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-  The tidal friction increases the length of a day by only 1 second in 50,000 years.  This effect is small compared to the effects of earthquakes and slight changes in the Earth’s internal mass distribution.  These mass distribution changes can change Earth’s rotation by as much as one second per year.  Thus the introduction of the “leap second” in our time standards.
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-  Other reviews available on this subject:
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-  #1899,  #1900,  #1901 about moons in our Solar System.
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----  Comments appreciated and Pass it on to whomever is interested. ----
---   Some reviews are at:  --------------     http://jdetrick.blogspot.com -----
--  email feedback, corrections, request for copies or Index of all reviews
-  to:   -------    jamesdetrick@comcast.net  ------  “Jim Detrick”  -----------
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 -----   707-536-3272    ----------------   Friday, August 26, 2016  -----
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The moons in our Solar System.

-  1901  -  The moons in our Solar System.  This Review is a summary of the moons around each of the eight planets and new Dwarf Planets.  182 moons discovered so far.
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-----------------------------1901 -  Moons around the planets.
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-  Review #1900 discussed the moons in our Solar System and the forces that keep them in orbit.  This Review #1901 discusses each of the planets with their respective moons that are all outside the Roche Limit.
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-  There are only 3 natural moons orbiting the 4 inner planets.  Earth has one and Mars has two.  Our Moon was created by an enormous collision that the Earth had with a Mars-size object some 4.6 billion years ago.  Mars on the other hand captured its two moons as orbiting asteroids, Phobos and Deimos.
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-  Like our moon, Phobos and Deimos are tidally locked to Mars, always showing the same face as they orbit.  These two captured asteroids were once part of the Asteroid Belt.  Phobos is only 14 miles in diameter and Deimos only 7.8 miles in diameter.  Phobos’ orbit is at 5,287 miles.  Deimos farther out at 14,577 miles taking 30.35 hours to complete a single orbit.
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-  These are the inner Rocky Planet moons.  Beyond the Asteroid Belt things get much different for the four gaseous planets:
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-  Jupiter has 67 known moons, but, if you count smaller “ moonlets” the count is over 200 satellites.  The 4 largest moons can be seen with binoculars under good conditions.  They were first discovered in 1610 by Galileo using his first telescope.
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-----------------  Io is the most volcanically active.
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-----------------  Europa likely has a massive subsurface ocean.
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-----------------  Ganymede is the largest moon in our Solar System.  Even larger than the planet Mercury.
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-----------------  Callisto is also thought to have a subsurface ocean.
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-  Jupiter’s inner smaller moons have diameters less than 124 miles.  These orbit within 124,000 miles of the surface.  The outer moons are irregular satellites with more eccentric orbits captured by Jupiter’s intense gravity.
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-  Saturn has at least 150 moons and moonlets.  53 or Saturn’s moons have names.  34 of these are less than 6.2 miles in diameter.  The inner large moons are Mimas, Enceladus, Tethys, and Dions.  These moons have rocky cores but are composed of mostly water ice.
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-  Titan is Saturn’s largest moon at 3,200 miles diameter.  Titan is large enough to have its own atmosphere, which is primarily nitrogen.  There are recordings of hydrocarbons and methane ice crystals in this nitrogen atmosphere.  There are liquid methane-ethane lakes at the poles.
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-  Uranus has 27 known moons.  Titania is the largest at 981 miles diameter.  Miranda at 293 miles. Miranda is primarily ammonia and carbon dioxide ice.
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-  Neptune has 14 known moons,  Triton is the larges at 1,678 miles diameter.  It orbits 220,427 miles form Neptune, about the same distance our Moon orbits Earth.
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-  Past Neptune are the Dwarf Planets, Pluto’s orbit and beyond.  Pluto has the large moon Charon first discovered in 1978.  The two smaller moons Nix and Hydra discovered in 2005.  The 5th moon Styx discovered in 2012.
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-  Charon is so large that Pluto and Charon orbit each other, and are tidally locked together.  Ammonia hydrates and water crystals on the surface of Charon suggest active cryo-geysers.  Pluto may have a subsurface  ocean as well.
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-  Other Dwarf Planets include Eris, Haumea, Makemake, and Sedna.  Haumea has 2 known moons.  Eris has one known moon.
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-  More satellites will surely be found in the future.  Ganymede is by far the largest, even larger than the planet Mercury.  On the smaller size satellites have been found orbiting Jupiter that are only 0.6 miles diameter.
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-  Other reviews available upon request on this subject:
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-  Review # 1899 -  Moon  - far-side and rainbows.  Also lists 8 more reviews about the moon
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-  --------------------------------------------------------------------------------------
----  Comments appreciated and Pass it on to whomever is interested. ----
---   Some reviews are at:  --------------     http://jdetrick.blogspot.com -----
--  email feedback, corrections, request for copies or Index of all reviews
-  to:   -------    jamesdetrick@comcast.net  ------  “Jim Detrick”  -----------
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 -----   707-536-3272    ----------------   Wednesday, August 24, 2016  -----
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Moons in our Solar System.

-  1900 -  How many moons are in our Solar System?  What causes a moon to fall out of orbit?  How can moons drift away or crash into their planet?  What is the Roche Limit?
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-----------------------------1900 -  Moons in our Solar System
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-  The Earth has only one Moon.  Mars has two, Phobos and Diemos.  Mercury and Venus, our two inner planets, have none.  So, there are only 3 moons orbiting the four rocky planets.
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-  It is a whole different story for the 4 outer gaseous planets and beyond:
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----------------------------  Jupiter  --  67 known moons.

----------------------------  Saturn  --  53 known moons.

----------------------------  Uranus  --  27 known moons.

----------------------------  Neptune  -- 14 known moons.
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----------------------------  TOTAL  --  161
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-  Pluto has 5 moons.
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-  So the definition of an orbiting moon needs more refinement.  A definition adopted in 2006 has the count for the Solar System:
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-----------------------------  TOTAL  --  173 know  moons
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-  If you include the Dwarf Planets, Pluto and beyond the count is:
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----------------------------  TOTAL  --  182 known moons.
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-  It does not stop there:
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--------------------------   76 known satellites around the asteroids in the Asteroid Belt.
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-------------------------      4  Trojan satellites sharing Jupiter’s orbit.
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--------------------------  39  near -Earth objects with 2 satellites each.
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--------------------------  14  Mars crossers
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-------------------------  84  Neptune crossers
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------------------------  150 small moonlets in Saturn’s rings.
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-  You count up all the known satellites orbiting other objects in the Solar System and the count becomes:
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---------------------------  545  known satellites.
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-  There are only 3 natural satellites in the Inner Solar System around the Rocky Planets.  Theory has it that Mercury and Venus had moons in the past but they have long ago impacted on the surface.
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-------------------------  Our Moon is 3,474 miles in diameter
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-------------------------  27.3% the size of the Earth.  That is over one forth the size.
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------------------------  1.23% the mass of the Earth.  The Moon is monthly Earth’s crust.
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-  What determines whether a moon will eventually crash into the planet or escape into free space?  It is called the “ Roche Limit”.
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-  If the moon’s orbit takes longer than a day the planet’s rotation slows down and the moon drifts further away to compensate due to the Conservation of Angular Momentum of the system.
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-    If the moon’s orbit is faster than the planet’s rotation then the opposite occurs.  The moon makes the planet rotate more quickly and the moon drifts closer to compensate.  It will eventually impact the surface of the planet.
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-  Our Moon has the first scenario.  It is slowly drifting away from Earth at a rate of ½ inch per year.
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-  Shortly after the Moon’s formation, 4.3 billion years ago, it was much closer and the Earth was spinning much faster.  A day on the Earth was only 6 hours. And, the Moon’s orbit took only 17 days.
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-   The Earth’s constant gravity pull eventually stopped the Moon’s rotation.  Now, only one face always faces the Earth.  And, the Moon’s constant gravity pull has been slowing the Earth’s rotation.  To maintain the total angular momentum of the system the Moon has been slowly drifting away to compensate.
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-  Today the Moon’s average distance is 238,855 miles.  It is in a slightly elliptical orbit with its closest at 225,309 miles and its farthest at 251,904 miles.  It takes a little over one second for reflected moonlight to reach the Earth.  ( That is also the delay in radio communications).
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-  If the Moon’s orbit actually gets close enough to reach the “ Roche Limit” the planet’s gravity will tear the body apart.  It all depends on several factors: mass, size, density, composition.  Our Earth - Moon limit is calculated to be 59,000 miles.  So, we are safe from a Moon impact.
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-  At 59,000 mile orbit the Earth’s gravity overwhelmingly over powers the gravity holding the Moon together near-side to far-side.  At that point the Moon would turn into a ring of material orbiting the Earth.  ( Like the rings of Saturn ).  Eventually that orbiting material  would crash into the Earth’s atmosphere and some to the surface.  That would be one enormous meteor shower, and meteorites peppering the Earth’s surface.
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-  For the average comet the Roche Limit is 11,185 miles orbiting Earth.  That comet if orbiting the Sun would be torn apart at 808,000 miles.
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-  Mars will experience the first moon landing with its moon Phobos.  Phobos is orbiting more quickly that a Martian day.  Phobos keeps drifting closer and closer to the planet.  In a few million years it will be torn into a ring and all the pieces will begin crashing in to the surface.
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-  Why don’t our own bonds of our body’s atoms get torn apart ?   We are certainly inside the Roche Limit.  What is holding us together?  It is the electromagnetic forces of the atoms that are much, much stronger that the force of gravity.
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-  Now, the same scenario would not work if out body approaches the gravity of a Blackhole.  The intense gravity there below the Roche Limit would pull our body apart like a string of spaghetti.
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-  All the moons in the Solar System are at least beyond the Roche Limit.  Otherwise, they would have already broken up on the surface of their planet.
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-  See Review #1901 to learn more about the many moons in our Solar System.
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-  --------------------------------------------------------------------------------------
----  Comments appreciated and Pass it on to whomever is interested. ----
---   Some reviews are at:  --------------     http://jdetrick.blogspot.com -----
--  email feedback, corrections, request for copies or Index of all reviews
-  to:   -------    jamesdetrick@comcast.net  ------  “Jim Detrick”  -----------
-  https://plus.google.com/u/0/  -- www.facebook.com  -- www.twitter.com
 -----   707-536-3272    ----------------   Tuesday, August 23, 2016  -----
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The far-side of the Moon and Rainbows

-  1899  -  The cow jumped over the far-side of the Moon.  The first sight of a new face for the world to see.  What did we learn?  That rainbows are only in your head.
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---------------------1899  -  The Far - Side of the Moon.
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-  The Moon orbit’s the Earth showing us only one face.  No one saw the far-side until 1959, but, the photo-quality was so poor.  The most that could be concluded is that it was very different than the near-side.  The large dark maria were not as numerous.  Maria is Latin for “ seas”.  Instead its surface was mostly bright, rugged highlands, crisscrossed with rays from large, fresh craters.
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-  The Moon was two distinct hemispheres of individual character.  The maria are ancient lava flows which erupted from the surface 3 billion years ago.  The eruptions were caused by the heat from decaying radioactive elements deep under the surface.  The heat melted the magnesium and iron-rich mantle producing liquid rock that covered the surface.
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-  The flowing magma formed giant impact features called “basins”.  Some are more than 620 miles in diameter.  The basins were caused by asteroids impacting the Moon some 4 billion years ago.  The basins created fractures that allowed magma to break through to the surface.
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-  Impact craters and basins cover the entire surface.  Not all basins are filled with lava.  Something must have caused the volcanic flooding of almost all the near- side basins but only a few of the far-side basins.
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-  The Moon’s crust consists of aluminum and calcium rich rocks.  The Moon must have been nearly totally molten covered by an ocean of magma in which these low density minerals floated to the surface.  The denser iron-rich minerals became the “ mantle”.  It was the mantle that slowly re-melted due to the heat from radioactive elements.  This magma erupted as maria basalts.
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-  The Moon’s crust is some 20 miles thick similar to parts of Earth’s crust.  The crust on the far-side is thicker than on the near-side.  Also, the Moon’s center of mass is offset a couple miles in the direction  of Earth.  This is what likely caused the Moon’s rotation to synchronize with its orbit of Earth.
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-  The half-life of the radioactive elements is 4.5 billion years where by it decays to lead.  The internal heat generated explains much of the surface, but, the rest is the result of a complex history of impacts, mare flooding, and other random geological events.  We  only partly understand why the near-side and far-side of the Moon are so different.  Maybe the cow knows.
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-  Another strangness is the “giant in the room”.  Compared with other rocky planets our Moon is so huge.  It’s crust is also similar the Earth’s rock having the same oxygen isotopes.  Minerals composed of sodium and calcium aluminum silicates are the same as Earth’s curst.
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-  The Moon’s formation occurred 4.6 billion years ago when two planets occupied the same orbit around the Sun collided in a grazing angle.  The ejected material formed Saturn-like rings around Earth.  Over thousands of years these rings accreted into a huge mass of orbiting particle eventually forming the Moon we have today.
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-  The Full Moonlight is 400,000 times dimmer than Sunlight.  This is not intuitive because our eyes protect us from huge brightness changes.  The 6th  magnitude stars mark the lower limits of human visual experience.  The upper limits is 9 trillion times brighter.
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-  We only see dimness in black and white.  With more light intensity we can see colors.  But, these colors only occur in our brains.  The photons are only electromagnetic pulses. They have neither luminosity or color.  Just as magnetism and electricity is not visible, neither are photons.  Instead photos deliver an electromagnetic force that excite the cells in the back of the eye.  The impulses for these cells produce the subjective perception of light and color.  That is why the rainbow of colors occurs strictly inside your head.
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-  Your brain’s 100 billion neurons are what creates the brightness and colors in our visual Universe.  It will be hard to convince you that the visual scene external to your eyes is only an illusion.
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-  The photons originated in the Sun.  The brightness of the Sun is 400 trillion, trillion watts.  What reaches us is only 1,000 watts per square meter.  The photons do not come from the Sun’s disk that we see.  Instead the inner most core , 1/200th of the volume , produces photons in the center compact fusion generator.  The outer edge is the photosphere where these photons are released.  This edge is only a few hundred miles thick.
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-  Eight minutes later the photons show up on Earth.  But, none turn in to colored light until your brain does its trick.  The energy of the photons depends on the frequency of the photon oscillations.  Higher frequencies carry more energy.  The frequency also controls the color the eyes detect and the brain registers.  The frequencies increase from red light to blue light.  The rainbows are only in you head.
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-
-  Other reviews available on this subject:
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-  #1704  -  There are two sides to get a Full Moon.  The size of the Moon is 27% the size of the Earth.  However, the Moon is only 1.2% the mass of the Earth.  To get a rocket to leave the Moon it needs to accelerate to only 5,400 miles per hour.
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-  #1681  -  Enceladus and Europa might support life?  We have 173 moons orbiting our 8 planets.  Over 150 asteroids also have orbiting satellites.
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-  #1678  -  Moon history from the beginning.  The Moon has almost  no atmosphere.  You can count cratering yourself on website “NASA Lunar Reconnaissance Orbiter”  www.moonzoo.org  The Moon is 250,000 miles away but these images are from only 400 miles away.
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-  #1450  -  Full Moon on Doug’s birthday.
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-  #1291  -  Two Moons over Miami.  The early Universe was a chaotic place.
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-  #1243  -  What is behind the Man in the Moon?  As the Moon cooled it preserved some water in the form of hydroxyl.  The Moon is spiraling away in its orbit 1.5 inches each year.
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-  #1651  -  Moon may be the best habitats for life.
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-  #64  -  written November 11, 2004.  What you did not know about our Moon.
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----  Comments appreciated and Pass it on to whomever is interested. ----
---   Some reviews are at:  --------------     http://jdetrick.blogspot.com -----
--  email feedback, corrections, request for copies or Index of all reviews
-  to:   -------    jamesdetrick@comcast.net  ------  “Jim Detrick”  -----------
-  https://plus.google.com/u/0/  -- www.facebook.com  -- www.twitter.com
 -----   707-536-3272    ----------------   Monday, August 15, 2016  -----
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