I guessed on these three
6. The life zone is too close to the star
7. Have unstable orbits
10. Anthropic principle
The hardest question to me was finding the courage to take it? And, it was easier than it truly seemed at times.
That's great feedback: "finding the courage to take it". Why was it intimidating? How could it have been presented to be less intimidating? Thanks so much!
It is most likely an individualized notion of taking a test--just anxiety. In my experience the best way to be prepared is to over-prepare. I believe internet communication can become too passive--without skyping or speaking to a "live" person to facilitate the test/discussion/seminar/ or even being in the physical presence of the interaction. It gets too comfortable.
That is just my opinion.
Other than that --I would do it again. . . (sounds kind of funny?)
Best to you
Sanjoy and all
Totally agree on some of the comments on Q6 and Q7.
Just imagine this: a group of astrobiology students on a tidally locked M-dwarf planet or on a planet in a binary system make a quiz.
Q6/Q7: This planet called Earth with that moon called Moon around that G-star called Sun can not harbour intelligent life because:
a) The 24h day-night cycle will make all complex life impossible
b) they only have one sun
c) their moon will cause crazy tides, no way there's anything complex surviving it
These question are actual central and crucial questions that we are currently working on (and probably can only answer with the cross-disciplinary approach of Astrobiology).
I don't even like the "most likely" or "most probably" new version, because we just don't know.
No offense, but this is little bit as if an astronomer would say the origin of life most probably happened at hydrothermal vents.