Lesson Quiz's AST 109

What is the typical spacing of 1-km sized asteroids in the belt

10,000,000 km

What is the closest temperature where you are sitting today

300 K

Why is Mars' atmosphere (2x) more dense in Spring/Fall than in Winter/Summer?

Carbon dioxide freezes into a polar cap in winter

Saturn radiates ~3 times energy received. What is the source of Saturn's excess heat?

Contraction (in the form of helium rain)

Which direction has the sun moved most on the sky (relative to the stars), since this time yesterday

East

Why are so few meteor craters on Earth

Erosion removes them rather quickly

Why is Saturn most oblate Planet

Fast spinning pushes the equator outward, low density

What could have parts of pluto reflect 98% of sunlight

Fresh snow

Why are much different fractions of types of meteorites found

Iron/stony-iron ones look unusual

Why is mars red

Its surface rocks were rusted by oxygen. (iron oxide)

The planet with more mass than the 7 other combined

Jupiter

Why is Mars so cold

Mars is 50% farther than Earth from the sun

Which is not a reason humans could live on mars

Mars' native plants could serve as food

Why are craters so sparse on Mercury?

Mercury cooled more slowly than Moon, and liquid/soft surface did not preserve craters

Standing on the moon, how often do you see 'earth-rise"?

Never

When do astronomical high tides happen

New Moon

Neptune emits 2.5 times the solar energy that comes in. WHy?

Radioactivity (fission) in the core

The moons of Jupiter are

Rocks

Why is Venus' albedo so high?

Sunlight is bouncing off light clouds

Why are the maria smooth compared to the highlands?

They formed long ago but after cratering was largely done

Why are craters so sparse on Venus

Thick atmosphere burned up many meteors

Why are Jupiter's inner Galilean moons more dense

Tides heat Io most, Callisto least

Which object has atmosphere most similar to Earths

Titan

What should you remember about Titania

Uranus' largest moon

Why are craters so rare on Io

Volcanoes paved over almost all craters

The moons of Saturn are largely

Water and ice