Titan is an interesting moon because:
A) beneath its clouds, Titan may be Earth-like, with liquid water.
B) the Huygens rover has sent back images of sedimentary rocks there.
C) it has a rich atmosphere that may resemble that of the early Earth.
D) it is known to have ice volcanism on its surface.
E) All of the above.
Question 2
Why would galaxies colliding in a small cluster tend to stick together, while galaxies in a large cluster tend to pass through each other?
What will be an ideal response?