Lecture 7 Flashcards
Which planet in our solar system has the highest surface temperatures?
Venus
Mars is sometimes perceived as a second Earth. Why is this incorrect?
Mars has a much smaller mass and it is also much smaller than Earth
Why does the atmosphere of Venus contain so much more CO2 than Earth’s?
On Earth most of the CO2 is locked away in sea sediments (carbonate rocks)
The planet Mercury is generally not regarded a suitable place for extraterrestrial life. Which one of the following statements is not a reason why we think that?
the planet has a thick CO2 atmosphere
What is the primary component in Venus’s atmosphere?
Carbon Dioxide
Which mechanism controls the surface temperature on Venus?
the Greenhouse effect
Which one of the following statements about Mars is incorrect?
Today’s Mars has a strong magnetic field because of the large amount of iron on the surface
We think there is still plenty of water on Mars, but where is it?
It sits in subsurface ice, in a large permafrost layer
Which one of the following statements about the large volcano Olympus Mons on Mars is incorrect?
It was created by the same plate tectonic motion that created the Valles Marineris
What kind of evidence did we find for past liquid water on Mars?
We see structures like dried out rivers and flood plains on the surface
How and why - do we think - did Mars lose most of its atmosphere?
Because Mars cooled quicker than the Earth and lost its protective magnetic field, which allowed the solar wind to erode the atmosphere
Why is Mercury not the best planet for astrobiology?
Mercury’s mass is too small to hold on to any type of atmosphere
Why is Mars the best planet for astrobiology?
Because we have compelling evidence that Mars once had liquid surface water
Mars’ atmosphere
95% CO2, 3% Nitrogen, argon, traces of oxygen and very thin
