1. Europa Clipper

2. Kuiper Belt, Dwarf Planets & the Oort Cloud

3. Kuiper Belt Discovered in 1992 Named for Dutch Astronomer Gerard Kuiper, who had PREDICTED its existence in 1951. Region beyond Neptune; 30 to over 50AU At least 70 000 small, icy, slow- moving, objects

4. Dwarf Planets And TNOs

5. The Problem of Pluto Pluto was discovered in 1930. Named after the god of the dead. Its position was predicted by perturbations in Neptune’s orbit From the beginning it was unlike any other planet. Its orbit is on a far different plane than the other planets, at a 17° angle from them and… is so elliptical (30 – 49 AU) that it crosses Neptune’s orbit.

6. Pluto and Charon Its size is very small, less than half Mercury’s radius and its mass is even less at only.002 of Earth Its Composition was at first thought to be a terrestrial planet, though isolated beyond the Gas Giants, later its composition was discovered to be icy, more like a comet than Earth. Its moon, Charon is unusually large, at half Pluto’s radius and orbits very close at 19,600 km. All this made Pluto very unique until…

7. Eris, and a new type of planet In 2005 another ‘planet’, called Eris after the Greek goddess of discord, was discovered It was very much like Pluto, a little larger with similar composition, a tilted (44°) and elliptical (39 – 97 AU) orbit, and a large moon. Recently more, (6+) other similar objects have been found. In August 2006 they and Pluto were called a new category of celestial objects, “Dwarf Planets” A Dwarf Planet: Orbits the Sun Has enough mass so that gravity makes them roughly spherical But have not cleared their orbit of other objects

8. Ceres One Dwarf planet does have a composition similar to Earth…Ceres Located in the asteroid belt It was once considered an asteroid it orbits in the asteroid belt between Mars and Jupiter at 2.77 AU It is between 909 & 975 km in diameter.

9. Dawn Mission

10. Trans-Neptune Objects (TNO’s) and other dwarf planets Pluto, Eris, Sedna and Orcus are all icy dwarf planets that cross Neptune’s orbit or come close to it At their greatest distance they pass into the Kuiper belt where comets orbit, They are known as ”TNO’s” About 10 such objects are known. There are probably many more dwarf planets orbiting far beyond Neptune. Possibly 100,000+ over 100 km in diameter.

11. Plutoids Plutoids are icy dwarf planets similar to Pluto. They orbit in the Kuiper Belt and in composition resemble comets. (Although exactly what gas the ice is varies) They Include: Pluto, Eris, Makemake and Haumea Some such as Sedna, Quaoar, Orcus and Varuna await a further observation before determination

12. Pluto’s Transient Atmosphere Nitrogen is especially common on Pluto It has an atmosphere of mostly nitrogen that only exists when its closer to the Sun. It freezes when Pluto reaches aphelion and vaporizes again as it approaches perihelion

13. Pluto and Charon are a “binary planet” because: 1.Charon has a radius (635km) more than half that of Pluto. 2.They orbit each other and are tidally locked so that both always face the same side to each other Two true moons Nix and Hydra orbit the pair.

14. Eris Eris, with a radius of 1200 km, is the largest of the Plutoids. It takes over 500 years to complete its 68 AU average orbit. It has one small Moon: Dysonomia

15. Makemake And Haumea At a radius of 950 km Makemake is the third largest plutoid. Debate raged over the status of Haumea Its elongated shape is the result of it fast spin. At a period of 4 hours, the fastest known So now it qualifies It has two small moons, Hi’iaka and Namaka

17. Oort Cloud

18. Hypothetical spherical cloud. No direct observations. Proposed by Ernst Opik (1932), Jan Henrik Oort (1950) 50 000AU; defines gravitational boundary of solar system Source of long-period Comets

19. Oort Cloud Objects composed of ices (water, methane, and ammonia) 2 regions: outer sphere, inner disc Comets can not have formed on their current orbit Must be held in an outer reservoir Debris are redirected (as comets) by disturbances, such as passing stars, collisions, etc.

20. Sources http://www.lpl.arizona.edu/faculty/malhotra_preprints/ISP_Nov04/Kuipe rBelt.jpg http://www.lpl.arizona.edu/faculty/malhotra_preprints/ISP_Nov04/Kuipe rBelt.jpg http://www.cnes.fr/automne_modules_files/standard/public/p1135_ed7 7069b38b89947b9f6e5678e9af2adkuiper_pluton.jpg http://www.cnes.fr/automne_modules_files/standard/public/p1135_ed7 7069b38b89947b9f6e5678e9af2adkuiper_pluton.jpg http://discovermagazine.com/2004/nov/cover/outer-oort.jpg http://www.myastrologybook.com/OortCloud10q8x7.jpg http://en.wikipedia.org/wiki/Oort_cloud http://en.wikipedia.org/wiki/Ceres_(dwarf_planet) http://www.astro.ubc.ca/~lallen/kbo/general.html http://www.enchantedlearning.com/subjects/astronomy/solarsystem/kui per.shtml http://www.enchantedlearning.com/subjects/astronomy/solarsystem/kui per.shtml Universe: The Definitive Visual Guide