Earth and its Solar System ims

Two of the inner planets are ____________.

• Venus and Saturn

• Mars and Venus

• Earth and Neptune

• Mercury and Jupiter

Small pieces of rock that enter Earth's atmosphere and burn up are called ________________.

• stars

• meteors

• meteorites

• asteroids

_______________ are pieces of rock that strike the surface of a moon or planet

• Meteoroids

• Comets

• Meteor showers

• Meteorites

_____________ for a planet to form in the asteroid belt.

• It was too cold

• Some of the asteroids were too large

• Jupiter's gravity may have been too great

• The asteroids moved too slowly

A comet develops a tail because of _________________.

• energy from the sun

• Earth's atmosphere

• the Oort Cloud

• Jupiter's gravitational pull

Evidence suggests that _______________ originate in the Oort Cloud located beyond the orbit of Pluto.

• comets

• asteroids

• meteoroids

• meteorites

What is the basic astronomical unit based on ?

• The distance Mercury, the closest planet, is from the Sun.

• The distance Earth, the planet the scientists live on, is from the Sun.

• The distance Neptune, the farthest planet, is from the Sun.

• 1,000,000,000 km

What causes planets and other space objects to revolve around the Sun rather than going off in a straight line?

• inertia-once an object is traveling in a circle it will keep traveling in a circle

• pressure-the air in space pushed the object toward the Sun

• gravity-the Sun is pulling the object toward it

• gravity-the object is pulling the Sun toward it

Which of the following is a common trait of the inner planets?

• They are the same size.

• The atmospheres are made up of the same gases.

• They all have water.

• They all have a solid outer layer.

The outer planets are mainly composed of which of the following?

• hydrogen and oxygen

• hydrogen and helium

• helium and oxygen

• nitrogen and helium