Exam 4: Space and Time

The Sun is the center of our solar system.

Our solar system formed from a large cloud of gas and dust called a __________.

If Pluto is not a planet (but rather a dwarf planet), then where do astronomers believe its point of origin?

Nuclear fusion occurs in the __________ of the Sun.

Because of Earth's relatively small mass, our planet's atmosphere is composed

Mercury, Venus, Earth, and Mars are called the __________ planets.

The outermost planets in the solar system (Jupiter, Saturn, Uranus, and Neptune) are small, dense, and rocky.

A carbonaceous chondrite is a type of

__________ has been used to determine the age of Earth and other objects in the solar system.

For the principle of __________ , the present is the key to the past.