AST101H1 Chapter Notes - Chapter 7: Earth Mass, Planetary Science, System 7

• School: UTSG
• Department: Astronomy & Astrophysics
• Course: AST101H1
• Professor: Bryan Gaensler

Document Summary

Gaileleo"s telescopic observations began a new era in astronomy in which the sun, moon and planets could be studied for the first time as worlds rather than as mere lights in the sky. Comparative planetology: the study that compares the worlds to one another, seeking to understand their similarities and differences. Astronomers use the term planetology broadly to include moons, asteroids and comets as well as planets. Composition (by mass): 98% hydrogen and helium, 2% other elements. The largest and brightest star in our solar system: contains more than 99. 8% of the solar system"s total mass. It is a roiling sea of hot hydrogen and helium gas (5500 c) Surface is speckled with sunspots that appear darker in photos because they are slightly cooler than their surroundings. Sun is gaseous throughout and the temperature and pressure both increase with depth.