AST 205 EXAM WITH CORRECT
ANSWERS ONLY
● The ellipticity of Mars' orbit makes seasons more extreme in its southern hemisphere.
Axial tilt ranges from 0° to
60°-CORRECT ANSWERS✔✔What makes Mars' seasons more severe?
- Its atmosphere must have once been
much thicker for its greenhouse effect to
allow liquid water on the surface.
- Somehow Mars lost most of its
atmosphere, perhaps because of its
declining magnetic field.-CORRECT ANSWERS✔✔Why did Mars change?
- Mars is cold, dry, and frozen.
- Strong seasonal changes cause CO2 to
move from pole to pole, leading to dust
storms.-CORRECT ANSWERS✔✔What is Mars like today?
very thick CO2 atmosphere w/ surface pressure 90 x
of Earth (like 1km
,depth under water on
Earth).
● produces an
EXTREME green-house
effect (Delta T = 500C!)
● Slow rotation produces a
very weak Coriolis effect
and little weather-CORRECT ANSWERS✔✔Atmosphere of Venus:
Carbon is in rocks and the oceans on Earth-CORRECT ANSWERS✔✔Venus and Earth should be similar.
Why don't we
have an equally thick CO2
atmosphere?
- Runaway greenhouse effect made Venus too
hot for liquid oceans.
- All carbon dioxide remains in atmosphere,
leading to an extreme greenhouse effect-CORRECT ANSWERS✔✔How did Venus get so hot?
- Temperatures are just right for oceans of
water.
- Oceans keep most CO2 out of atmosphere.
- Nitrogen remains in the atmosphere.
- Life releases oxygen into atmosphere.-CORRECT ANSWERS✔✔How did Earth's atmosphere end up so
different?
, - Carbon dioxide cycle acts as a thermostat.-CORRECT ANSWERS✔✔Why does Earth's climate stay
relatively
stable?
1. Every mass attracts every other mass.
2. Attraction is directly proportional to the product of
their masses.
3. Attraction is inversely proportional to the square of the distance between their centers.-CORRECT
ANSWERS✔✔universal law of gravitation:
- 1. The orbit of each planet is an ellipse with the Sun at
one focus.
- 2. As a planet moves around its orbit it sweeps out equal
areas in equal times.
- 3. More distant planets orbit the Sun at slower average
speeds: p2 [yrs] = a3 [AUs]-CORRECT ANSWERS✔✔Kepler's Law of Planetary Motion
the relationship between the orbital period and average orbital
distance of a system tells us the total mass of the system.-CORRECT ANSWERS✔✔Newton's laws of
gravity and motion showed that:
- Change in total energy is needed to change orbit
- Add enough energy (escape velocity) and
object leaves-CORRECT ANSWERS✔✔How do gravity and energy together allow us
to understand orbits?
ANSWERS ONLY
● The ellipticity of Mars' orbit makes seasons more extreme in its southern hemisphere.
Axial tilt ranges from 0° to
60°-CORRECT ANSWERS✔✔What makes Mars' seasons more severe?
- Its atmosphere must have once been
much thicker for its greenhouse effect to
allow liquid water on the surface.
- Somehow Mars lost most of its
atmosphere, perhaps because of its
declining magnetic field.-CORRECT ANSWERS✔✔Why did Mars change?
- Mars is cold, dry, and frozen.
- Strong seasonal changes cause CO2 to
move from pole to pole, leading to dust
storms.-CORRECT ANSWERS✔✔What is Mars like today?
very thick CO2 atmosphere w/ surface pressure 90 x
of Earth (like 1km
,depth under water on
Earth).
● produces an
EXTREME green-house
effect (Delta T = 500C!)
● Slow rotation produces a
very weak Coriolis effect
and little weather-CORRECT ANSWERS✔✔Atmosphere of Venus:
Carbon is in rocks and the oceans on Earth-CORRECT ANSWERS✔✔Venus and Earth should be similar.
Why don't we
have an equally thick CO2
atmosphere?
- Runaway greenhouse effect made Venus too
hot for liquid oceans.
- All carbon dioxide remains in atmosphere,
leading to an extreme greenhouse effect-CORRECT ANSWERS✔✔How did Venus get so hot?
- Temperatures are just right for oceans of
water.
- Oceans keep most CO2 out of atmosphere.
- Nitrogen remains in the atmosphere.
- Life releases oxygen into atmosphere.-CORRECT ANSWERS✔✔How did Earth's atmosphere end up so
different?
, - Carbon dioxide cycle acts as a thermostat.-CORRECT ANSWERS✔✔Why does Earth's climate stay
relatively
stable?
1. Every mass attracts every other mass.
2. Attraction is directly proportional to the product of
their masses.
3. Attraction is inversely proportional to the square of the distance between their centers.-CORRECT
ANSWERS✔✔universal law of gravitation:
- 1. The orbit of each planet is an ellipse with the Sun at
one focus.
- 2. As a planet moves around its orbit it sweeps out equal
areas in equal times.
- 3. More distant planets orbit the Sun at slower average
speeds: p2 [yrs] = a3 [AUs]-CORRECT ANSWERS✔✔Kepler's Law of Planetary Motion
the relationship between the orbital period and average orbital
distance of a system tells us the total mass of the system.-CORRECT ANSWERS✔✔Newton's laws of
gravity and motion showed that:
- Change in total energy is needed to change orbit
- Add enough energy (escape velocity) and
object leaves-CORRECT ANSWERS✔✔How do gravity and energy together allow us
to understand orbits?
