The Co-Accretion theory claims that the Earth and Moon formed together from the same clump of material in the solar nebula. The Capture theory claims that the Moon was a wandering planetesimal that was captured into orbit around Earth. Even if Mars did have plate tectonics, we would expect the mountains on Mars to be generally larger than the mountains on Earth. Assuming the impact erosion theory is correct, suppose we are looking at a section of Mars and of Earth's Moon, each with roughly the same crater density. One of Jupiter's four major satellites, Ganymede, has a surface divided between lighter and darker colored regions.
Titan is the only one of the three bodies with a significant atmosphere.
Upstairs in the lobby of the Sid W. Richardson building, you can find several extremely dense and massive meteorites made of pure iron. An asteroid about 1 kilometer in size is thought to have caused a catastrophic explosion off the coast of Chile about 13 million years ago, according to a paper presented at last week's meeting of the American Geophysical Society. Suppose an asteroid were spotted heading toward Earth with a diameter of about 2 kilometers. Assume both asteroids have the same density and both strike the Earth with the same velocity. Show your work.