- 2782 - KUIPER BELT - Name the Tenth Planet? - There are some conflicting opinions whether the 10th planet should be called a “planet”. Maybe it should be called a large asteroid, or comet? All the objects found beyond the orbit of Neptune are called Kuiper Belt Objects, KBO‘s . Named after Peter Gerard Kuiper, 1905 - 1973.
-
-
-------------------------- 2782 - KUIPER BELT - Name the Tenth Planet?
-
- Most people can name the 9th planet. It’s Pluto. Ok, so Pluto got demoted to a “Dwarf Planet” But, It is still “my ninth planet“. Then there is a 10th planet that is even bigger than Pluto and has not yet been named. It does have a number, 2003UB313.
-
- Planet 10 was first discovered October 21, 2003 (Michael Allen Gallegos’ birthday), however, continued analysis and re-analysis of the data did not confirm it as a planet until January 8, 2005. (That is Nathan Scott Rush’s birthday. I think they should name the planet “Nathan”.)
-
- KBO’s were named after Peter Gerard Kuiper, 1905 - 1973. Born in the Netherlands he became a US citizen in 1937. He discovered the moon of Uranus, Miranda in 1948. He discovered the moon of Neptune, Nereid in 1949. He was the first to speculate the existence of a belt of comets beyond Neptune in 1950.
-
- The Kuiper Belt is the home to billions of these objects, mostly comets. The difference between an asteroid and a comet is that asteroids are composed of mostly rock and metal (iron, nickel). Comets are composed of mostly ice and dust. It all has to do with where the object first formed in the accretion disk during the birth of the Solar System.
-
- The Sun first formed some 10 billion years ago. The Sun was spinning and spinning with it was a large collection of dust and debris in what is called the accretion disk. Heavier debris particles tended to be closer to the Sun due to its massive gravity. Gases and lighter particles tended to be further out in the orbiting accretion disk.
-
- After some 5 billion years the planets formed as a collection of these particles bound together by their own gravitational attractions. The four inner planets, Mercury, Venus, Earth, and Mars, are terrestrial planets made up of mostly rock and metal. They retain an atmosphere of heavier gases such as carbon dioxide and oxygen.
-
- Asteroids are made of the same material and lie in orbit mostly between Mars and Jupiter. This “Asteroid Belt” would probably be another planet except Jupiter’s strong gravity keep pulling the asteroids apart and will not allow the pieces to coalesces into a planet
-
- Further out on the accretion disk the four giant, gaseous planets were formed, Jupiter, Saturn, Uranus and Neptune. These are mostly a mixture of the lighter gases, hydrogen and helium. Beyond the orbit of Neptune which is 30 times the Earth-Sun distance, astronomical units, or 30 AU’s, are the Kuiper Belt Objects (KBOs).
-
- An astronomical Unit AU, the Earth-Sun distance is 93,000,000 miles.
-
- Pluto is one of these Kuiper Belt Objects and was thought to be the biggest until now. Pluto has a more elongated orbit than the nearly circular orbits of the other planets. Its orbit extends from 30 AU to 50 AU over a 250 year period.
-
- It is too easy to put comets and asteroids in separate boxes. However, there are asteroids that behave like comets and comets that behave like asteroids. Comets are composed of dirty ice, or frozen mud around a rocky core. Comet tails are vaporized ice and dust. It is hard to tell a dead comet from an asteroid.
-
- In turn, an asteroid surrounded by gas and dust must be a comet. Pluto and Triton have the composition of comets and are believed to have formed by gravity crunching comets together. It is equally difficult to categorize them according to their orbits because many collisions and near-misses with giant planets have scattered individual orbits all over the solar system.
-
-The Kuiper Belt extends out to 500 AU and contains billions of comets. Most of these comets still lie somewhat in the accretion disk or the ecliptic plane with some inclinations above or below the plane.
-
- Still further out to the far reaches of the Sun’s gravity there are billions more comets. Between 500 AU and 100,000 AU is the “Oort Cloud” of objects that completely surround the Sun in a sphere of objects completing orbits in thousands of years.
-
- This is our Solar System. It was the astronomer, Nicolas Copernicus, who in 1543 moved the Earth and discovered our Solar System. It was his revolutionary theory that the Earth was not the stationary center of the Universe, but moved around the Sun.
-
- A Greek astronomer, Aristarchus of Samos, had the theory in 300 BC, but the theory was not accepted for 1000 years until Copernicus published the book, “ On the Revolutions of the Heavenly Spheres” in 1543, the same year he died. 95% of his book was dedicated to providing convincing evidence to a few key ideas: The planets orbit the Sun in the same direction.
-
- The Earth is one of them spinning on its axis once a day and orbiting the Sun once every year. In order of distance from the Sun, Mercury is the closest, followed by Venus, Earth and its Moon, Mars, Jupiter and Saturn(9.5 AU).
-
- Uranus was discovered in 1781 at 19 AU. Neptune was discovered in 1846 at 30 AU. Ceres was the first and biggest asteroid to be discovered in 1801, only 2.77 AU and having a 621 mile diameter. It too was thought to be a planet at the time of its discovery.
-
- Pluto was not discovered until 1930 at 40 AU, 1,429 mile diameter. Pluto has been defined as a planet, but equal argument is given to the 9th and 10th “planets” being KBO’s, asteroids or comets.
-
- How do astronomers discover planets, comets and asteroids, and how do they know how big they are?
-
- To see the 10th planet (on July 31,2005 ) SB313, focus your telescope to a point high in the morning sky a few hours before the Sun comes up in the Constellation Cetus. Cetus is a constellation of stars called the Sea Monster, or the Whale. The constellations that surround it are Orion, Taurus, Aries, Pegasus (The Great Square) and Capricorn. It lies between the variable star Mira and the galaxy NGC253.
-
- UB313 is found as a dim “starlight” that moves over time with respect to the background stars that appear stationary. UB313 is just a dot of light through the telescope.
-
- The telescope needs to look at the same spot for over 3 hours to see the dot of light move relative to the background stars. Tracking it longer over time can determine its velocity, direction, and its orbit. Once the orbit is defined the period can be calculated from the equation figured out by Johan Kepler in 1596:
-
------------------------------ period^2 = radius^3
-
----------------------------- 561 years^2 = 68 AU^3
-
- It takes SB313 561 years to complete a single orbit. SB313 average radius (actually its semi-major axis since its orbit is an ellipse not a circle) is 68 AU.
-
----------------------------- 68 AU^3 = period^2
-
----------------------------- 314,432 AU^3 = 561 years^2
-
----------------------------- Pluto’s radius is 39.53 AU and period is 248.54.
-
----------------------------- radius^3 = period^2
-
----------------------------- 61,772 AU^3 = 61,770 years^2
-
----------------------------- P^2 = r^3
-
----------------------------- 248.54^2 = 39.53^3
-
----------------------------- 61,772 = 61,770
-
------------------------------ Johan Kepler figured this out in 1596
-
- To determine the size we measure the amount of sunlight it reflects. The amount must be determined by its size and how reflective its surface is. UB313 is now 9 billion miles away, 97 AU. It takes over a day for sunlight to reach its surface and be reflected back to Earth.
-
- Sunlight travels 97 AU (9 billion miles) to reach SB313 bounces off and returns 96 AU to reach Earth. Light is traveling 186,287 miles per second, 499 seconds to travel 1 AU, or 8.32 minutes for light to travel from the Sun to Earth. To travel the 193 AU round trip to SB313 takes 96,351 seconds, or 26.76 hours.
-
- SB313 is the 3rd brightest object we have seen in the Kuiper Belt. So we do not know how big it is, but we do know how bright it is and brightness is due to two factors: how big it is and how reflective it is.
-
- If it were all white snow and 100% reflective (nothing is 100%) then it must be 1,373 miles in diameter. If it had the same reflectivity as Pluto (60%) then it must be 1,413 miles diameter. If it is like Pluto’s moon, Charon (38%), then it must be 2,206 miles diameter. Today’s best estimate is that it is one and one-half the size of Pluto, or about 2,000 miles diameter. It is definitely a larger planet than Pluto (1,413 miles diameter).
-
- The surface temperature is estimated to be -405 F degrees. Spitzer’s infrared telescope has tried to measure heat radiating from this surface. To the limits of their instruments they get no readings which sets an upper limit on SB313’s diameter. It must be less than 2,200 miles.
-
- The wavelength response in the 1 to 2.5 microns of the reflected infrared sunlight has exactly the same pattern as light reflected from Pluto. This pattern is the signature of solid frozen methane, CH4 (1 carbon, 4 helium, atoms). The interior of SB313 is likely frozen ice and rock but the surface is frozen gaseous methane.
-
- SB313 is a Kuiper Belt object that can be categorized as a large asteroid or comet. If we choose to call it a planet, so be it. Ceres is the largest “asteroid” that was discovered in 1801. It is 600 miles diameter, 50% the diameter of Pluto. It was called a planet when it was first discovered.
-
- We have defined orbits of about 175,753 objects in our Solar System as of 2005. (http://neo.jpl.nasa.gov/neo.html to see current orbiting data of these objects) 498 of these objects are considered potentially hazardous asteroids that approach Earth less than 4.6 million miles (.05AU, less than 5% of the distance between Earth and the Sun)
-
- 530 of these identified objects orbiting the Sun are beyond the orbit of Pluto. This is 530 out of a billion estimated to be in the Kuiper Belt. 100,000 of these comets are expected to be Pluto-like objects.
-
- The Kuiper Belt extends from 30 AU to 500AU. The 500AU is considered the end of the gravitational influence of our Sun. Beyond that, 500AU to 100,000 AU, is the Oort Cloud of comets that contains several billion comets in a spherical distribution entirely around the Sun. This cloud of comets extends to 20% of the way to the nearest star.
-
- Here are some of the 530 objects in the doughnut shaped Kuiper Belt so far identified after searching only 15% of the sky to date with our most modern telescopes as of 2005. Many more discoveries are expected, and many new objects will be as large as Pluto:
-
---------------------------- 2003UB313: 2000 mile diameter, 561 year orbit,
38 AU to 97 AU distance, 44 degree incline, 4th brightest object in the Kuiper Belt.
-
---------------------------- Pluto: 1413 miles diameter, 258.5 year orbit, 39AU distance, 17.17 degree incline, Brightest KBO.
-
---------------------------- Charon: 770 mile diameter, Pluto’s moon
-
---------------------------- 1998WW31: , has its own moon
-
---------------------------- 2001KX76: 750 miles diameter,
-
---------------------------- 2000WR106: 523 miles diameter,
-
---------------------------- Varina: 550 miles diameter,
-
---------------------------- Ceres: 600 miles diameter,
-
---------------------------- 2003EL61: 700 miles diameter, 285 year orbit,
35 to 52 AU distance, 28 degree incline, The 3rd brightest KBO in the Kuiper Belt.
-
---------------------------- 2003VB12, Sedna: 995 mile diameter, 11,500 year orbit, 76 AU to 950AU, The most distant object seen in our Solar System stretching from the beginning of the Kuiper Belt and extending into the Oort Cloud of comets.
-
---------------------------- 2002LM60, Quaoar: 800 mile diameter, 7.9 degree incline
-
---------------------------- 2003EL61: 932 mile diameter,
-
---------------------------- 2005FY9: 700 mile diameter, 307 year orbit,
39 AU to 52 AU distance, 29 degree incline, the 2nd brightest object in the Kuiper Belt.
-
- This Review was written August 14, 2005. Much more has been discovered in the last 15 years, but, this is a good starting point as astronomy reaches out beyond Pluto.
-
- See Review 1660 for a more current update of Kuiper Belt Objects, in 2014.
-
- See Review 2142 written in 2018. Planets beyond Pluto. - Planets beyond Pluto are in the Kuiper Belt of comets, asteroids and sub-planets. Our new Horizon spacecraft is exploring these objects and is due to reach them in January,2019. This same spacecraft passed Pluto in 2006
-
- July 30, 2020 543 2782
----------------------------------------------------------------------------------------
----- 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
--------------------- Thursday, July 30, 2020 -------------------------
-----------------------------------------------------------------------------------------
No comments:
Post a Comment