Monday, August 29, 2016

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?
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-----------------------------1903  -  Juno’s mission arriving at Jupiter
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-  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.
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-  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.
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-  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 ).
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-  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.
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-  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.
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-  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 ).
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-  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.
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-  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.
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-  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.
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-  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.
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-  The magnetic field generates powerful auroras at the cloud tops that is 1,000 times stronger than Earth’s auroras.
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-  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.
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-  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.
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-  Other reviews available on this subject:
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-  #1880  -  More about the Juno mission
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-  Lists 4 other reviews about Jupiter’s moons and rings.
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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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Friday, August 26, 2016

The Moon and Angular Momentum.

-  1902  -  How the Moon uses the Conservation of Angular Momentum.  The math involved.
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-----------------------------1902  -  The Moon and Angular Momentum.
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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.   Our Moon is drifting away at 1 ½ inches per year.
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-  The orbital angular momentum of the Moon is 29 *10^33        kg^2 / second.
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-  The rotational angular momentum of the Earth is 7.1 * 10^33       kg^2 / second .
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-  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.
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-----------------------  Momentum  =  mass  *  velocity  =  mass  * distance / time
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---------------------  Angular Momentum  =  mass  * radius ^2  * angular velocity.
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-  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.
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-  To calculate the Angular Momentum of the spinning Earth:
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-----------------------  Mass  =  6 * 10^24 kilograms
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----------------------  Radius^2  =  (  6.4*10^6 meters )^2
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----------------------  Angular Velocity  =  2*pi radians  /  24 hours
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----------------  Angular Velocity  =  2*pi radians  /  86,400 seconds  =  7.3 *10^-5 radians per second
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-  The rotational inertia of a uniform sphere is:
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-----------------------  Inertia  -  2/5 mass * radius^2
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------------------------  I  =  2/5 m*r^2
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-  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:




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------------  Angular Momentum =  0.4 * (6 * 10^24) * ( 6.4*10^6)^2 * ( 7.3*10^-5)
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------------  Angular Momentum =  7.3 * 10^33     kilograms * meters^2 / second.
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-  The more accurate calculation for the Earth’s rotational angular momentum is reduced by 20%:
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-------------  Angular Momentum =  7.1 * 10^33       kilograms * meters^2 / second.
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-  We now make the same calculation for the Moon’s rotational angular momentum;
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---------------------  Momentum  =    2/5 *  m *  r^2  * w
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----------------------  Mass of the Moon  =  m  =    7.35*10^22    kilograms
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---------------------  Radius  =  r  =  1.74*10^6  meters
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--------------------- Angular Velocity  =  w  =  2*pi  /  27 days
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--------------------- Angular Velocity  =  w  =  6.24  radians  /  2,332,800  seconds
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--------------------  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.
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---------------------  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”  -----------
-  https://plus.google.com/u/0/  -- www.facebook.com  -- www.twitter.com
 -----   707-536-3272    ----------------   Friday, August 26, 2016  -----
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Wednesday, August 24, 2016

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”  -----------
-  https://plus.google.com/u/0/  -- www.facebook.com  -- www.twitter.com
 -----   707-536-3272    ----------------   Wednesday, August 24, 2016  -----
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Tuesday, August 23, 2016

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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Monday, August 15, 2016

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.
-  --------------------------------------------------------------------------------------
----  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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Wednesday, August 10, 2016

A century of astronomy:

-  1898  -  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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---------------------1898  -  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 Ia 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 orbit’s 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 Ia 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 Galaxy.  Pioneer 11 does Jupiter fly-by.
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Soviet Venera 9 lands on Venus.  1976 - Viking I and II land on -  1975 - 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 Ia 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, and 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.
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-  #1458  -  Astronomy helps society.  Other inventions that came from astronomy work.
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-  #641  -  To be a good writer you need to be more like an astronomer and less like a physicist.
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Saturday, August 6, 2016

The mysterious Neutron Stars, Pulsars, and Quasars

-  1897  - The mysterious Neutron Stars, Pulsars, and Quasars create radio bursts of energy that astronomers are still trying to explain.
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---------------------1897  - The mysterious Neutron Stars, Pulsars, and Quasars
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-  There are mysterious radio bursts coming to us from far away galaxies.  Since 2007 some 20 pulses have been recorded.  The pulses only last for a few milliseconds, but, they release the energy equal to a million suns.
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-  These 20 events were viewed in telescopes that can observe only a small patch of sky at any one time.  If astronomers could view the entire sky at one time they estimate that there are 10,000 radio bursts occurring every day.
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-  Astronomers have no explanation as to the source of this enormous energy.  Some ideas include colliding Neutron Stars, exploding Blackholes, snapping Cosmic Strings of space-time.
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-  This radio energy passes through the expanses of space encountering magnetic fields, plasma clouds of charged particles, and other Cosmic stuff.  If we really understood these radio bursts and could measure them precisely they could be a whole new “ telescope” to see the composition and structure of the Universe.
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-  Astronomers are studying “ Pulsars” which are rapidly spinning Neutron Stars. ( See Footnote (1))  These are collapsed stars that are only a few kilometers in diameter, but, extremely dense, atom nuclei collapsed into neutrons at the core.
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-  As the Pulsars rotate they swing a beam of radiation across our line-of- sight.  These radio signals appear as pulsating blips.  However, ever so often a radio signal will blip with so much energy it will saturate the electronics destroying the measurement signal.  These bursts of energy only last up to 5 milliseconds.
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-  After several of these occurrences over several years astronomers are convinced the bursts are originating in far away galaxies.  By measuring the signal “ dispersion” of higher frequency signals versus lower frequency signals astronomers can infer these great distances.  Higher frequencies arrive faster after traveling through intergalactic plasma, ie: charged electrons.  Lower frequencies are slowed by this same medium.  By measuring this delay astronomers can calculate how much intergalactic space the signal has traveled.
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-  Radio bursts from Quasars are quite common. ( See Footnote (2)).   But, these signals are much weaker.  The fast radio bursts referred to above are 1,000,000 times brighter than Quasars.  The theories on what causes this are also extreme.  
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-  Cosmic Strings are superconductors of electric currents that snap in space-time creating a burst of electromagnetic radiation.
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-  Or, Blackholes exploding in a burst of radio waves.  Maybe these are “tiny” Blackholes that formed in the first few seconds of the Big Bang.
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-  Or, the massive collision of two Neutron Stars.  It is all still a mystery.
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-  In March of this year, 2016, astronomers uncovered a burst that reoccurred 11 times in 16 days.  This recurring signal dispels theories of a single event like exploding Blackholes, or colliding Neutron Stars.  This event has a process that could regenerate itself.
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-  It could be that the rapid rotation of a Neutron Star could generate an enormously powerful magnetic field.  Called a “Magnetar“.  Somewhat similar to Solar Flares on our Sun’s surface, a magnetic field could “ snap” releasing a torrent of energy, accelerating charged particles , that in turn could emit radio bursts.
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-  Regardless of the source these signals they could act as Cosmic lasers that could more accurately describe the structure of the Universe.  The astronomy world has a new focus of concentration.   There is a lot more to learn here.  An announcement will be made shortly, stay tuned.
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-  (1)  Pulsars  -  The first discovery of a Neutron Star occurred in 1967 when a graduate student discovered a strong source of radio waves.   The pulses of radio waves were arriving at exactly 1.337301 second intervals.
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-  Now known as “ Pulsars” they are Neutron Stars left behind by supernova explosions.  The stars spin as the result of the Conservation of Angular Momentum as the star collapses in size.   The spinning star creates a magnetic field that is a trillion times as strong as the Sun’s.  At the magnetic poles beams of radiation escape.  When the magnetic poles don’t align with the rotation axis a sweeping beam rotates rapidly.
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-  Pulsars have been discovered that are rotating 625 times per second.  Only a Neutron Star could spin that fast without tearing a part.
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-  (2)  Quasars are powerful radio emissions coming from distant galaxies.  The galaxy centers are Blackholes with rapid rotating disks of inflowing material.  The friction, centripetal force, angular momentum , and gravitational energies all compete to produce intense radiation, more than from 1,000 galaxies the size of the Milky Way.
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-  The rapidly rotating disk drives two jets of escaping plasma in opposite directions out the poles.  When the jets hit intergalactic gas they produce hot spots with radio lobes.  The jets are formed inside twisted magnetic fields that contain and guide the charge particles.
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-  By measuring the orbital radius  ( r ) and the orbital velocity ( v ) of the gas clouds orbiting the Blackhole at the center of the galaxy we can calculate the mass inside the radius.
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-----------------------------  Mass  =  r * v^2  /  G

-------------------  G  =  Gravitational Constant  =  6.67*10^-11  m^3/( kg*sec^2)
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------------------  Velocity  =  v  =  800 kilometers per second
------------------  Velocity  =  1,790,000 miles per hour.
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------------------  Radius  =  r  =  60 lightyears
------------------  Radius  =  5.6 * 10^17 meters
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-----------------  Mass  =  ( 5.6*10^17) * (8.0 * 10^5)^2  /  6.67*10^-11
-----------------  Mass  =  5.4*10^39 kilograms
-----------------  Solar Mass =  2.0*10^30 kilograms
-----------------  Mass  =  2.7 * 10^9  Solar Mass
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-  The mass in the Blackhole , the central region of the galaxy, is equivalent to 2.7 billion Suns.
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-  (3)  Other Reviews available:
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-  #1327  -  Neutron Stars  -  The surface is solid and harder that a diamond, 50 trillion times denser than solid lead.  Its magnetic field is a trillion times more intense than that of our Sun.
-  #  1273  -  Neutron Star mergers.
 -  #1192  -  The new zoo of Pulsars.
-  # 642  -  Neutron Stars, Pulsars, and Magnetars.
-  #  861  -  Cannon Ball Stars
-  #625  -  Neutron Stars.
-  #21  -  Stars grow old.
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-  (4)  Different names for Neutron Stars:  Magnetars, Gamma Ray Bursters, Binary Neutron Stars, Gamma Ray Flares.
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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
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Thursday, August 4, 2016

Dark Energy and the expansion of the Universe

 -  1896  -  Astronomers are trying different methods to measure the accelerating expansion of the Universe.  The hope is for new discoveries to point to the source of “Dark Energy” that is creating this repulsive force.
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---------------------1896   -  Dark Energy and the expansion of the Universe.
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-  Astronomers are convinced the Universe is expanding.  And, it is expanding at an accelerating rate.  In the last few decades technology has advanced so fast, astronomers are able to create a 3-D map of this expansion and the form it takes.  It appears more like a spider web with filaments connecting nodes separated by voids but growing bigger.
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-  Three primary measurement methods are being used:
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-  (1)  The Hubble Telescope observing Type 1a supernovae explosions.
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-   (2)  The Planck Satellite measurements on the Cosmic Microwave Background radiation.
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-  (3)  The Baryon Oscillation Spectroscopic Survey measuring pressure waves in the spacing of nodes and voids between galaxy clusters.
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-  All three methods peg the expansion rate at about 150,000 miles per hour per mega parsec.  A mega parsec is 3.3 million lightyears distance.  This equates to 45,500 miles per hour per million light years.  All three methods have results within 8% of each other.  But, 8% leaves room for new discoveries.  What can explain these differences?
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-  Here are the results of each method of measurement:
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-  (1)  Type 1a supernovae are explosions of a White Dwarf Star that accumulates mass to reach 1.4 Solar Mass.  This limit of gravitational pressure collapses electrons into their nuclei creating the recoil in a “ standard candle”  supernova explosion.
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-  These measurements get the expansion rate at  49,485 miles per hour per million lightyears distance.  The measurement error is calculated to be + - 2.4%
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-  (2)   The Planck Satellite measurements get the expansion rate at 45,417 miles per our per million lightyears.  This measurement error is +- 1%.
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-  (3)  The BOSS measurements reported the same result as Planck’s except the measurement error a +-1/5%.  The expansion rate of 45,417 miles per hour per million lightyears.  BOSS got this studying the patterns in clustering of 1,200,000 galaxies.
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-  The difference is 4,068 miles per hour.
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-  An 8% difference in different measurements of the same acceleration rate.
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-  Each method is trying to refine the measurements and calculations to reduce measurement error.
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-  (1)  The Hubble Telescope is measuring objects of “ known” brightness, called Intrinsic Brightness.  They calculate distances by measuring dimness and by measuring the shift in frequency , the spread of wavelength, traveling through expanding space.  Besides Type 1a supernovae, Cepheid Variable Stars are also used because their pulsation rates can be correlated to their Intrinsic Brightness.
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-  The Hubble Telescope measurements are working to refine their results by measuring  two other types of stars, RR Lyrae Variable Stars  and Red Giant Stars.
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-  These particular type stars are identified in a galaxy where the distance is accurately known through other methods.  Then, calculate the Intrinsic Brightness.  “r “ is the distance.
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----------------------  Measured Brightness   =  Intrinsic Brightness  /  (4 * pi * r^2)
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-  (4 * pi * r^2) is the surface area of a sphere of the expanding light radiation bubble.
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-  When the same type of stars are identified in the most distant galaxy the Intrinsic Brightness is used to calculate the distance.  The goal is to reduce the measurement errors to less than 1%.
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-  The Hubble Telescope is also beginning to use Gravitational Lensing to image galaxies that were previously too dim to see.  A cluster of galaxies, 100 times more massive than our Milky Way Galaxy can bend the light beams from the much more distant galaxies behind them.  The focused beams act as a “magnifying glass“.
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-  (2)  The Planck measurements were made of the slightest temperature variations of the Cosmic Microwave Background radiation.  They are extending these measurements beyond just temperature to the ‘polarization” of this radiation of the ancient light that originated 380,000 years after the Big Bang.
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-  (3)  Baryonic Acoustic Oscillations are sound waves that have stretched into today’s distribution of galaxies and voids.  The Cosmic Microwave Background contains the same pressure waves that originated at that same time after the Big Bang.  The pressure wave changes that have occurred over the last 13.4 billion years is a measure of how Normal / Dark Matter and Dark Energy have competed in governing the rate of expansion.
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-  In the early Universe the mass was concentrated and gravity could actually slow down the rate of expansion.  This lasted for the first 7 billion years.  By then the mass had spread out so much gravity’s influence dissipated.  The repulsive force of Dark Energy took over dominance and the Universe has been accelerating its rate of expansion ever since.
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-  Astronomers are trying to learn what causes the vacuum of space to have a repulsive force?  Is this force every where the save?  Does this repulsive force change over time?  Called a mysterious Dark Energy , it could be an evolving energy field and not just a constant pressure?
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-  8% is not a big difference in measurement results, but, astronomers are convinced it points to something missing.
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-  Theories have proposed a  new type of particle, a new type of neutrino that may be affecting these measurements.
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-  Put together these measurements are creating a 3-D map or the Observable Universe.  The picture is one of galaxy strings like filaments connecting galaxy cluster, called nodes. The spaces between are giant voids, nearly empty space containing only a few atoms per cubic meter and no galaxies.
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-  This spider web tapestry is very similar to the neurons and nodes in the human brain.  These astronomy reviews are designed to stretch your brain.  Once stretched it will not return to its previous size.  Enjoy!
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---   Some reviews are at:  --------------     http://jdetrick.blogspot.com -----
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