ASTR 151 Study Guide - Contin, Hellas Planitia, Johann Gottfried Galle
Document Summary
Chapter 10: why is opposition the best time to see mars from earth, mars is largest and brightest in the night sky at opposition, when earth lies between mars and the sun. Mars is closest to earth during opposition: why are some martian oppositions better than others for viewing mars, because the planets do not move at constant speeds around their orbits. Oppositions near martian perihelion are less frequent, occurring once every 15 years: for a century, there was speculation that intelligent life had constructed irrigation canals on mars. What did the canals turn out to be: highly cratered and eroded areas around which surface dust occasionally blows, imagine that you will be visiting the southern hemisphere of mars during its summer. Describe the atmospheric conditions you might face: strong surface winds (without rain or snow) sweep up the dry dust, carry it high into the stratosphere, and eventually deposit it elsewhere on the planet.
