ASTRO 101 MODUEL 1

The Astronomical Unit (AU) as defined by astronomers is

the average distance between the Earth and the Sun

Which celestial body is closest to us? Moon Mars Sun Milkyway

Moon

The star that provides energy for life on Earth is

The Sun

Of these, which is the largest? Earth The Solar System Jupiter The Milky Way Galaxy The Universe

The Universe

A large body in space that consistently makes its own light (instead of merely reflecting another body's light) is called a star a planet a moon a light year a satellite

a star

The way scientists know that a hypothesis in astronomy is a reasonable description of nature is to

do experiments and make observations about the predictions of the hypothesis

Even with the best and largest telescopes, we can't see all the stars in the Milky Way Galaxy, even though these same telescopes can show us other galaxies. Why is that?

dust in the space between stars builds up over large distances and blocks the light of stars behind the dustier parts of the Milky Way

By the term universe, astronomers mean

everything that we can observe

All molecules (like molecules of water or carbon dioxide) are made up of

two or more atoms

Which of the following is the Earth NOT located in? the solar system the Milky Way Galaxy the Local Group of galaxies The Virgo supercluster

you can't fool me, we are located in all of the above