Chapter 10 - Terrestrial Planets Flashcards
Inferior planet
An inferior planet is a planet that orbits closer to the Sun than Earth does. The two inferior planets in our solar system are Mercury and Venus.
Does Mercury have an axial tilt?
No it does not. So it has no seasons
Does Mercury have an atmosphere? And what does it mean if it does or doesn’t? hint - what does it and does it not have protection from ? What about erosion? Temp regulation?
No, Mercury does not have an atmosphere.
- No protection from radiation
- No protection from impacts
- Slow erosion (only erodes from impacts)
- No atmospheric pressure
- No temperature regulation
What is the Caloris basin?
- One of the largest impact craters in the solar system
- Formed by a massive asteroid impact
- Surrounded by mountains and ridges
- The opposite side of Mercury has “weird” terrain caused by shockwaves from the impact
What is Mercury’s near-space environment like?
- Mercury has a weak magnetic field
- Mercury has no moons
Does Venus have an axial tilt?
Yes, Venus has an axial tilt of 180 degrees.
- Venus spins slow and backward (retrograde)
- A Venus day (sunrise to sunrise) is shorter than its year
—- 243 Earth days to rotate once
—- 225 Earth days to orbit the sun
—- Because of the backward spin, a solar day on Venus is 117 Earth days.
Does Venus have volcanic structures?
Yes, many. Including large bulges called coronae
Venus’ Runaway Greenhouse Effect
- A thick CO2 atmosphere traps heat
- Sunlight enters and heat can’t escape
- It’s surface temperature is ~ 900F
- This extreme heat caused oceans (if there were any) to evaporate. –> more water vapor –> more heating
- It’s an extreme example of the greenhouse effect gone wild
What is Venus’ near-space environment like?
It has no moons and no magnetic field - probably due to its slow rotation
Does Mars have an axial tilt?
Yes. Mars has an axial tilt of 24 degrees. Mars has seasons
What are some details about Mars’ hemispheres?
- The northern hemispheres is lower and smoother
- The southern hemisphere is higher and heavily cratered
What is Olympus Mons?
- It’s the largest volcano in the solar system.
- It’s 2.5x the height of Mount Everest
- 370 miles wide
- It’s a shield volcano with gentle slopes
-** It likely formed from long lasting lava flows** - It’s located in Mars’ Tharsis region
Describe the Valles Marineris. What is it? How big is it? And how was it formed? Where is it located?
- It’s a massive canyon system on Mars
- It’s over 2,500 miles long - spans the US
- It was formed by tectonic stretching, not water
- One of the largest canyons in the solar system
- Near the Tharsis volcanic region
Describe splash craters on Mars
- Craters with ejecta that look like mud splashes
- Caused by impacts into icy or water- rich ground
- Ejected materials flows outward into lobes
- Suggests subsurface water or ice
- Common on Mars, rare on dry bodies like the Moon
What are seasonal flows on Mars?
- Dark streaks that appear and grow in warm seasons
- Found on steep slopes near the equator
- Might involve briny/salty water
- It’s still debated whether it’s water, dry flows or dust movement
- It suggests Mars may still have some liquid activity
Describe the polar ice caps on Mars
- Mars has two ice caps North (water ice) and South (water and CO2 ice)
- CO2 freezes in winter, thickening the caps, and sublimates in summer, which shrinks them
- They provide clues about Mars’ climate history and water resources
Describe the ice plates near Mar’s equator
- There are layers of water ice near Mars’ equator, found beneath the surface
- These ice plates are buried under dust and soil
- They are believed to be remnants of ancient ice deposits and some may be accessible for future exploration
What is Mars’ near space environment like?
It has a weak magnetic field and has two moons - Phobos and Deimos
Does Mars have weather?
Yes dust storms + dust devils.
