Assignment 4: The Changing Pluto

The Changing Pluto 

How the surface of Pluto appears to be in a closer view

History & Properties of Pluto

Pluto is now classified as a dwarf planet in the solar system.  It is also known to be a member of a group of objects that orbit in a disc-like zone beyond the orbit of the planet Neptune called the Kuiper Belt. This distant realm is occupied with thousands of miniature icy worlds, which formed early in our solar system history. These icy, rocky bodies are referred to as Kuiper Belt objects or transneptunian objects.  Pluto is approximately two-thirds the diameter of Earth's moon and probably has a rocky core surrounded by a mantle of water ice. Other forms of ice such as methane and nitrogen frost coat its surface. Pluto's mass is about one-sixth of the size of Earth’s moon!  Pluto is more massive than Ceres (the dwarf planet that resides in the asteroid belt in between Mars and Jupiter) by a factor of 20.

The view of Pluto in the solar system 

Clyde Tombaugh discovered Pluto in 1930.  Within the years 1977-199, Pluto’s lopsided orbit brings it slightly closer to the sun than of Neptune.  It is predicted that it will take at least 230 years before Pluto moved inward of Neptune’s orbit for 20 years.  In 1978, the American astronmers Hames Christy and Robert Harrington discovered Pluto's unusually large moon in which was later named Charon.  It was later discovered in 1988 that Pluto indeed did have an atmosphere, and in 2005 the scientists discovered that there are two additional moons in Pluto as well.  The two moons were named Nix and Hydra.  In 2006, NASA’s New Horizons mission launches on a path in order to explore Pluto and the Jupiter Belt region, and the spacecraft is scheduled to reach Pluto in 2015 (this year!).  Throughout the years Pluto was distinguished as it’s own planet, however in 2006 The International Astronomical Union classifies Pluto as a dwarf planet, along with recognizing that there are similar worlds just like Pluto beyond the orbit of Neptune distinguished as “plutoids”.  In 2011, the astronomers discovered a fourth moon in Pluto named Kerberos, orbiting the icy dwarf planet, and they discovered tis existence using the Hubble Space Telescope.  Finally in 2012, the most recent discovery involving Pluto was that there is indeed a fifth moon as well, named Styx, which was discovered during the search of potential hazards to the New Horizon mission. 

Clyde Tombaugh

Photograph of Clyde Tombaugh

Clyde Tombaugh was born in 1906 a farm family, and as a boy he developed an interest in stargazing.  Both his father and his uncle encouraged stargazing. The first telescope Clyde ever looked through actually belonged to his uncle, and eventually the first telescope he ever owned was bought from Sears. By 1925, Clyde was not satisfied with his store bought telescope and decided to build one for himself. The telescope that was built by Clyde in 1925 was only the first of more than thirty telescopes he was to build over his lifetime.  In 1928, Clyde completed the construction of a very accurate 23 cm reflector, and it was this telescope that Clyde made the observations that led him to a job offer from the Lowell Observatory. Clyde made very detailed drawings of his telescopic observations of Jupiter and Mars.  His observations led him to an offer to work as a junior astronomer in Lowell. Clyde gladly accepted the job and joined the search for Percival Lowell's "Planet X", which was a planet beyond Neptune. After ten months of very hard work, Clyde Tombaugh discovered an object in which he then named Pluto. For many years, Pluto was considered to be the ninth planet in our solar system, but eventually the astronomers learned more about the planets and discovered a new group of objects known as the Kuiper Belt Objects.  It then became clear that Pluto was more like the objects in that belt than the other eight planets. In August 2006, Pluto was re-classified as a dwarf planet, a couple years after Clyde Tombaugh death at the age of ninety on January 17, 1997.

Plutinos

diagram illustrating large plutinos

Plutinos were named after the dwarf planet Pluto, in which was the first discovered object with this resonance.  Plutinos form and occupy the inner part of the Kuiper Belt and represent about 1/4 of the known Kuiper Belt objects in which is also known as the KBOs. Plutinos are the largest class of the resonant trans-Neqtunian objects, which are the bodies in orbital resonances with Neptune.  After Pluto was discovered, the first official plutino to be discovered was named (385185) 1993 RO, and was discovered on September 16, 1993.  Although the majority of plutinos have low orbital inclinations, a great number of them follow orbits similar to that of the dwarf planet Pluto, with inclinations in the 10–25° range and eccentricities around 0.2–0.25, reaching in perihelia inside, or even close to the orbit of Neptune and aphelia close to the main Kuiper Belt’s outer.  The general orbital periods of plutinos cluster approximately 247.3 years (1.5 × Neptune's orbital period).  The plutino that follows the most highly inclined orbit (34.5°) is named 2005 TV.

References

http://solarsystem.nasa.gov/planets/profile.cfm?   Object=Pluto&Display=OverviewLong

http://starchild.gsfc.nasa.gov/docs/StarChild/whos_who_level2/tombaugh.html

http://www.planetariodorio.com.br/bloguinho/media/k2/items/cache/4effff5398b13b476604d4d8       450bedfd_XL.jpg

http://en.wikipedia.org/wiki/Plutino

http://upload.wikimedia.org/wikipedia/commons/4/4f/ESO-L._Cal%C3%A7ada_-_Pluto_(by).jpg

http://www.planetsforkids.org/upload/-Pluto-a.jpg

http://upload.wikimedia.org/wikipedia/commons/thumb/4/47/TheKuiperBelt_60AU_LargePlutin       os.svg/250px-TheKuiperBelt_60AU_LargePlutinos.svg.png