ASTR 1101 : Midterm Notes
Document Summary
Rocky composition: mercury, venus, earth, mars, meteors, the biggest asteroid (ceres) Icy composition: pluto, rings around planets, titan, eris. Asteroids and comets 0. 4-1. 5 gm/cm3 [rocky but with voids, like a rubble pile] Reason for seasons: during summer, the sun does not climb so high in the sky as in winter, so the heating of the ground is from slanted angles and makes the ground warmer. It is not the variations in the earth-sun distance. The tilt of the earth on its axis is a factor, without the tilt there literally would not be any seasons. 3. 9 extra hours of sunlight make the summer hotter than winter. The kuiper belt- objects are like pluto, made up of ices (appropriate for the out solar system) with a rocky core. Every hard surface in our solar system has craters, so pluto does too. The only exception to that is when the surface has been "recently" reprocessed, for example by the volcanoes on.
