AY 101 Lecture Notes - Lecture 10: Kuiper Belt, Comet Nucleus, Oort Cloud
Document Summary
Planetesimals are small objects out as tiny particles that grew over time through condensation. Generally small, only a few miles or less in size. Often non-spherical in shape owing to their low mass and gravity. Found in large numbers in specific regions of the solar system. Believed to be the building blocks of larger worlds. The ones we see today are (cid:862)lefto(cid:448)ers(cid:863) fro(cid:373) the for(cid:373)atio(cid:374) of the pla(cid:374)ets. Near the sun, planetesimals are made mostly of rock and metal. Asteroids congregate in the inner solar system. Most asteroids orbit between mars and jupiter. Far from the sun, ices became an additional major constituent of planetesimals, due to lower temperatures. We call an icy planetesimals a comet nucleus like asteroids, most comet nuclei are only a few miles to tens of miles across and too small to be spherical. Because the amount of heat received from the sun decreases inversely with the square of the distance from the sun.
