Transcript dec5

Final Exam
Wednesday December 18at 9:30 AM
Covers Chapters 11 & 12
Allowed one sheet of notes writing on one side
HST Image
The end of Planet X
Pluto is much too small to be planet X.
Voyager flyby of Uranus and Neptune
provided much more accurate masses of
those planets. With the better masses,
planet X was no longer required.
Trans-Neptune Objects
Kuiper belt lies between 30 AU (the distance to
Neptune) and about 50 AU. It contains a large
number of small, icy bodies that orbit the Sun
beyond Neptune.
Since the first one was discovered in 1992, over
1200 more have been identified.
Plutinos, the little Plutos
Approximately 1/4th of the TNO’s discovered to
date are in a 3-2 resonance with Neptune the
same as Pluto.
10th Planet?
Eris, goddess of warfare and strife, is 2400 km
in diameter, 27% more massive than Pluto
and has a satellite Dysnomia, daughter of Eris
and the demon spirit of lawlessness.
Discussion
Should Eris be considered a planet?
Orbit of Eris
Same as Pluto?
Planets & Dwarf planets
Dwarf planet: any object that orbits the Sun,
not another planet, with enough mass to
make it round.
Planet: any dwarf planet that has enough
gravitational influence to clear its orbit of
other objects.
Ceres
Dawn
Vesta
Ida
Mathilde
Discussion
What do you think causes the gaps in the
asteroid belt?
Kleopatra
Comets
3 types of Comets
Short period – those with orbital periods less
than 20 years.
Intermediate period – those with orbital
periods between 20 and 200 years.
Long period – those with orbital periods
greater than 200 years.
Comet HaleBopp
Comet
Hale-Bopp
Blue ion tail
White dust
tail
Comet tail always
point away from
the sun
Comet McNaught 2007
Comet Encke
Tempel 1