Notes

Slide Show

Outline

1	Chapter 9 Remnants of Rock and Ice Asteroids, Comets, and Pluto Chapter Outline Remnants from Birth of Solar System Asteroids Meteorites Comets Pluto: Lone Dog or Part of a Pack? Cosmic Collisions: Small Bodies Versus the Planets
2	Asteroids move relative to “fixed” stars.
3	Orbital resonances with Jupiter disrupted the orbits of planetesimals, preventing them from accreting into a planet. Those that were not ejected from this region make up the asteroid belt today.
4	Locations of the asteroids.
5	Close-up views of asteroids studied by spacecraft.
6	How are meteorites related to asteroids?
7	Meteor showers
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9	Anatomy of a comet.
10	How do comets get their tails?
11	How do Comets get their tails?
12	Comets occasionally collide with the Sun.
13	Where do comets come from?
14	Pluto’s orbit
15	What is Pluto like?
16	Pluto: Planet or Kuiper Belt comet? Whether Pluto should be called a “planet” is a matter of opinion, but its properties suggest that it is a Kuiper belt comet. Its composition and orbital properties match those of other Kuiper belt comets and do not fit in with the other planets. It is the largest known Kuiper belt comet today, but there may be larger ones still awaiting discovery. Approximately 800 Kuiper belt comets are now known.
17	Cosmic collisions
18	Shoemaker-Levy 9
19	Shoemaker-Levy 9
20	Did an impact kill the dinosaurs? We are not certain whether an impact was the sole cause, but a major impact clearly coincided with the mass extinction in which the dinosaurs died out, about 65 million years ago. Sediments from the time show clear evidence of an impact, and an impact crater of the right age has been found near the coast of Mexico.
21	The impact 65 million years ago:
22	Sediments with clues: CSI Cretaceous
23	Is the impact threat a real danger, or just media hype?
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25	The Big Picture The smallest bodies in the solar system—asteroids and comets—are our best evidence of how the solar system formed. The small bodies are subjected to the gravitational whims of the planets, particularly the Jovian planets. The subtleties of resonances play a major role in sculpting the outer solar system. The interplay of large and small bodies brings us meteorites to teach us our origins, comets and meteor showers to light up the sky, and impacts that can alter or obliterate life as we know it. Pluto is called the ninth planet, but it bears much more similarity to the thousands of Kuiper-belt comets than to the other eight planets.