ASTR 1210 Lecture Notes - Lecture 13: Ballpoint Pen, Mariner 10, Dwarf Planet
Document Summary
Orbital shape: all planets orbit in same direction, 8 major planets with didn"t finish. Planetary scale: planets much smaller than sun. Separation: ***planets are tiny compared to the distances between them. Grapefruit analogy (shrink by factor of 10) Earth 100x smaller, size of ballpoint pen (1. 3 mm or . 13cm) Sun earth distance = 15 meters. Sun jupiter distances = about 75 meters. Planet sizes much much smaller than separations. Major features of objects in solar system: size, distance, mass, composition, other notable features. Radius: 6,400 km = 1 r(subscript) earth. Distance to sun: 150,000,000km = 1 au (10,000x dia. Average density: 5. 5 g/cm3 (heavier than water) Surface temp: 290 k or about 300k (liquid water) Important features: only place known to have life at present time, only place with surface liquid and oxygen in atmosphere in the solar system. Large amount of oxygen comparatively deteriorates quickly but life replenishes it: surprisingly large moon (relative to size)