Astrobio115 Ch3 Part2

Chunks of rock and metal that orbit the Sun but are much smaller than the planets are referred to as

• comets

• dwarf planets

• meteors

• asteroids

Pluto, Eris and Ceres are all examples of

• Kuiper belt objects

• dwarf planets

• asteroids

• planets

One of the unusual features of the Earth's moon is that it is

• very large

• very small

• made mostly of rock

• keeps one side facing the Earth

According to the nebular theory for the formation of the solar system,

• planets should be rotating in the same direction as they orbit the Sun

• planets can be rotating in any random direction compared to the direction they orbit the Sun

• planets should be rotating in the opposite direction to the direction they orbit the Sun

• no prediction is made as to the directions of rotations of the planets

Planetary systems discovered around other stars

• all have exactly the same layout as the planets in our own solar system

• all have completely different layouts as the planets in our own solar system

• exhibit a range of different layouts, some being very similar to our solar system while others being very different

• all have very similar but not identical layout to our solar system

Which of the following materials present in the solar system had the highest condensation temperatures?

• metals

• rocks

• hydrogen and helium gases

• hydrogen compounds like water, methane, and ammonia

In the outer regions of the solar nebula where temperatures were low,

• only rock and iron could condense

• only hydrogen compounds could condense as ices

• hydrogen and helium gases were able to condense

• in addition to rock and iron, hydrogen compounds also condensed as ices

The most abundant materials in the solar nebula were

• hydrogen compounds like water, methane, and ammonia

• hydrogen and helium gases

• metals

• rocks

Inward migration is a hypothesis used to explain why

• Jupiter-sized planets are seen orbiting close to some stars

• some stars do not have Jupiter-sized planets

• some stars do not have planets at all

• Terrestrial-sized planets are seen orbiting far from some stars

Which of the following properties of the planets in our solar system is NOT explained by condensation theory?

• direction of revolution

• rotation rates

• chemical compositions

• orbital shapes