Astro 3 HW 5

About how far from the sun is the Kuiper belt?

About how far from the sun is the Kuiper belt?

40-70 AU

About how large are most meteors that hit the Earth's atmosphere?

Smaller than a grain of sand

All the planets, without exception,

revolve about the sun in the same direction.

Approximately how far from the sun is the main asteroid belt?

2-3 AU

How do we measure the masses of planets? By —

studying the orbits of their moons.

Is the present solar system in general spinning more rapidly or less rapidly than the original large gas cloud from which it formed?

more rapidly

Statistically speaking, how often might we expect an event the size of the Chelyabinsk meteor, or Tunguska, based on these events?

once per century

The Red Spot of Jupiter is

• a weather feature

• larger than the Earth in size

• variable in size

• long-lived (since the 1600s)

The atmospheres of the Jovian planets consist mostly of

hydrogen (H2)

The average surface temperature of Venus is higher than that of Mercury. Why?

Venus' atmosphere traps energy (heat) from the sun.

The contraction of an interstellar cloud to become a star is caused by — force

gravitational

The inner planets of our solar system are mostly composed of rocky material because

because of the nearness of the sun, the lighter elements had vaporized before they formed.

True (A) or False (B): Most comets are periodic.

False

What compound may play the same role on Titan as water does on Earth (existing simultaneously as gas, liquid, & solid phases)?

methane

What factors determine how long it takes a planet to orbit the sun?

distance from the sun only

What features are most abundant on Callisto and almost completely absent on Europa and Io?

Impact craters

What informs us about the distribution of sizes of the bodies orbiting in Saturn's rings?

how the rings scatter sunlight at different wavelengths gives the size distribution

What is the most distant planet from the sun?

Neptune

What is the name of Pluto’s largest moon?

Charon

What is the name of the first known asteroid-moon pair?

Ida & Dactyl

Which is the least likely type of planetary body to have an atmosphere?

low mass, high temperature

Which of the following are more typical of the jovian planets?

• hydrogen/helium atmospheres

• mean density around 1-2 g/cc

• icy rings

• outer solar system

Which of the following best describes the composition of a cometary nucleus?

"dirty" ices

Which of the following is a transneptunian object?

Eris

Which of the following processes of erosion occurs today on Mercury?

 meteoritic impacts