1. Minor Bodies of the Solar System
Solar System Debris:
Minor Bodies of the Solar System
Asteroids
Comets
Meteoroids

2. ~few hundred miles
How
big?
sand
grain

3. * Where are they? Everywhere! . . . But concentrated mainly in the:
Main Asteroid Belt
Kuiper Belt
Oort Cloud

4. Asteroids

5. * Debris left-over
from solar system
formation!
Average separation  4 million miles
p. 197

6. 35 mi
Ida & Dactyl

7. Asteroids
viewed
from
Earth
p. 198

8. Near-Earth Asteroids: Orbits pass near and/or cross
Earth’s orbit.
20 mi
Asteroid
433 Eros

11. Asteroid 1994 XM1
Missed Earth by
65,000 mi!

12. Comets

13. Kuiper Belt

14. Is Pluto just the largest KBO?
Kuiper Belt Object
(KBO) SC
Galaxy
4.6 hrs
* KBOs: mainly
icy in composition ?
Is Pluto just the largest KBO?

15. Oort
Cloud
some
comets
originate
here
100,000 AU
p. 203

16. Many comets orbit
well out of plane
of planets’ orbits.

17. Comet Hyakutake (1996)
~ 50o

18. Ion tail: ions energized by solar photons.
Comet Hale-Bopp
(1997)
Ion tail: ions energized
by solar photons.
Dust tail: dust particles
scatter (reflect) sunlight.
Nucleus: ice with
intermixed ‘gravel.’ .
p. 201

19. March 1, 2001:
Hale-Bopp
~13 AU from Sun

20. Comet tails always
point away from the sun.
Solar wind +
radiation pressure
p. 202

21. Nucleus of Comet Halley
“Dirty Snowball”

22. Comet Borrelly
5 mi

23. Periodic comets eventually evaporate . . . Some
break up near the sun . . .

24. . . . And some comets dive into the sun.

25. Meteoroids

26. * Stuff falls on Earth continuously –
most of it harmlessly.
Meteor – streak of
light caused by
heating of Meteoroid
as it passes through
Earth’s atmosphere.

27. Meteorite – piece
of meteoroid that
reaches the
ground.

28. chipped from asteroids
Large meteoroids:
chipped from asteroids
Small meteoroids:
comet debris
Meteor showers

29. Leonid Shower
(mid-November)

30. Leo
Radiant
November, 2001

31. Leonid Storm of
Nov 17, 1966

32. “Thirteen of us, mostly students, drove to observe and record the Leonids atop Kitt Peak on the night of Nov , We formed a circle of chairs and began to study our assigned areas of the sky for meteors. It started off slowly, about 30/hour. After 3 hours it picked up dramatically, and we observed a peak of about 40/second that lasted for 10 to 20 minutes. This was 24,000 in a ten minute period, a rate of 144,000/hour. We stood in awe as the sky seemed filled with meteors.”