Astro chapter 1

A star is 230 light years away. The light we see tonight from that star left it

230 years ago

When the authors of our textbook say that astronomers are like police detectives

Both astronomers and detectives need to test their hypothesis against any evidence that they gather.

For scientists, an element (like gold) is defined by

The Number of protons

Of these which is the closest to us?

The moon

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

do experiments and observations about the predictions of the hypothesis.

By the term universe, astronomers mean

everything we can observe

The location of the Earth in the Milky Way Galaxy is

little less than 30,000 light year from the center.

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 the Milky Way.

You are on a camping trip, far away from city lights. You look up into the dark night sky, and see lots of stars, some brighter, some dimmer. All the stars you see with your unaided eye are

In the milky way

A large body in space that consistently makes its own light (instead of merely reflecting another body's light) is called

It's called a star

The laws of nature (as determined by scientists)

Stated regularity in the relations or order of phenomena in the world that holds, under a stipulated set of conditions, either universally or in a stated proportion of instances.

The natural object (not one that humans built) in space that's closest to Earth is

The Moon, at 384,400 km

The Astronomical Unit (AU) as defined by astronomers is

The average distance between earth and the sun

A light year is

The distance that light travels in a year.

Light travels 3 x 105 meters every second. That number in standard notation is

Three hundred and fifteen

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?

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

The smallest piece of an element (like gold or lead) that still has all the properties of that element is called

Atom

Of these, which is the largest?

Universe

The star that provides energy for life on Earth is

The sun