Astronomy Notes: Sunspots, Nebular Hypothesis, and Planets

What are sunspots?

What do models allow scientists to do?

List the inner planets (terrestrial planets).

• Mercury, Venus, Earth, Mars

• Jupiter, Saturn, Uranus, Neptune

• Earth, Mars, Jupiter, Saturn

• Venus, Mars, Jupiter, Neptune

List the outer planets.

• Jupiter, Saturn, Uranus, Neptune

• Mercury, Venus, Earth, Mars

• Earth, Mars, Jupiter, Saturn

• Venus, Earth, Neptune, Pluto

What are the three criteria that define a planet?

Asteroids, meteoroids, and comets are:

• Planets

• Leftover debris that did not form into larger planets or moons

• Stars

• Clouds of gas

The outer planets have thick atmospheres made of hydrogen and helium.

• True

• False

What is a protostar?

• A protostar forms at the center of the nebula, surrounded by gaseous and rocky debris.

• A protostar is a fully formed star that has begun nuclear fusion.

• A protostar is a type of black hole found in the center of galaxies.

• A protostar is a planet that orbits very close to its star.