Introductory Astronomy and Cosmology (PHYS 202) - Chapters 13 & 14 Review

One of the key reasons that professional astronomers (as opposed to the public) are interested in comets is that they

are icy pieces left over from the time that our solar system formed that can give us clues about that early time.

Why were asteroids not discovered until the 19th century?

asteroids are generally small compared to planets are require a good telescope and patient searching to spot them.

Chunks of solid material that survive passing through the Earth's atmosphere and are found on the Earth's surface are called

meteorites.

The large reservoir of comet nuclei far beyond Pluto, from which we believe new long-period comets come into the inner solar system, is called

the Oort Cloud.

The atmosphere of Venus is mostly carbon dioxide, and the atmosphere of the Earth has water vapor. Why are these two gases absent in the atmosphere of the satellite around Saturn called Titan?

Titan is so cold that carbon dioxide and water vapor freeze out.

If there are at least a million asteroids, how did spacecraft like Galileo survive their trip through the asteroid belt?

although there are many asteroids, they are widely spaced (there are lots of space between them).

One of the most perplexing issues raised by the discovery of thousands of exoplanets is the existence of "hot Jupiters" - planets with the masses and compositions of Jupiter, but orbiting closer to their stars than Mercury does in our solar system. What is our best idea currently about how such "hot Jupiters" came to be?

hot Jupiters formed further out in their star system, and then migrated inward somehow.

The first technique that allowed astronomers to find exoplanets involved

measuring changes in the radial velocity (Doppler shift) of the star caused by the pull of orbiting planets.

Comets change as they approach the Sun in their orbits. Which of the following statements about a comet approaching the Sun is FALSE?

the gravity of the comet nucleus holds on to the evaporated material, and it all eventually freezes back into the nucleus.

Among solid worlds, which type of world is most likely to have significant geological activity?

those that are the largest (and retain heat the best).