solar system

The inner four planets of our solar system are called the ___ planets and the next four are called the ___ planets.

• terrestrial, gas giants

• rocky, gas like

• hard, soft

• gas giants, terrestrial

The objects that eventually formed planets by colliding and merging are called ____.

• stars

• asteroids

• planetesimals

• solar nebula

Galileo's discovery of Jupiter's moons proved that not all celestial bodies orbit Earth, therefore, Earth is not necessarily the center of the solar system.

• True

• False

Mercury has the largest day-night temperature difference of all the planets in our solar system.

• true

• false

What causes Uranus' blue appearance?

• the vast oceans

• sulfuric acid in its atmosphere

• the ammonia ice droplets

• the methane in its atmosphere

Where are most asteroids located?

• orbiting all planets

• between Mars and Jupiter

• outside of Pluto's orbit

• between Earth and Venus

Pluto's orbit is so eccentric that at times, Pluto is closer to the sun than Neptune is

• True

• False

The dense concentration of gas at the center of the solar nebula eventually became the sun

• true

• false

The ____ of a planet is its apparent backwards movement as seen from Earth's sky.

• epicycle

• retrograde motion

• perihelion

• eccentricity

What characteristics do the gas giants have in common?

• ring systems and moons

• composed of lightweight elements such as hydrogen and helium

• are very large, 15 to 300 times the mass of Earth

• all the answers are correct