Star Systems
Galaxies
The Expanding Universe
The Future of the Universe
100
A group of two or more stars.

What is a star system?

100

A huge group of single stars, star systems, star clusters, dust and gas bound together by gravity.

What is a galaxy?

100

How long ago did the universe begin?

13.7 billion years ago

100

What is dark matter?

Matter that does not give off electromagnetic radiation

200

In a binary star, the smaller star is called ___

the dim star

200

Galaxies that appear to have a bulge in the middle with arms that spiral outward.

Spiral galaxies

200

What is the name of the galaxy we live in, and what is its type?

We live in the Milky Way galaxy, and it is a spiral galaxy

200

Name ONE of the possibilities that will happen to the universe in the future.

1. The universe will continue to expand, and all stars will burn out, resulting in a cold and dark universe.

2. The force of gravity will begin to pull the galaxies back together resulting in an enormous black hole.

300

A star system with three stars.

Triple Star

300

Galaxies that contain billions of stars but have little gas and dust between the stars.

Elliptical Galaxies

300

According to the __________, the universe formed in an instant, billions of years ago, in an enormous explosion.

Big Bang Theory

300

Who discovered dark matter?

Vera Rubin

400

As the companion star revolves around the brighter star, the companion star's gravity causes the bright star to ___

Wobble

400

Galaxies that do not have regular shapes

Irregular galaxies

400

According to ________, the farther away a galaxy is, the faster it is moving away from us.

Hubble's Law

400

Astronomers  infer that a mysterious new force, which they call ____, is causing the expansion of the universe to accelerate.

dark energy

500

A system in which one star blocks the light from another periodically.

What is an eclipsing binary

500

Active young galaxies with huge black holes at their centers.

Quasars

500

The leftover thermal energy from the big bang is called _____.

cosmic background radiation

500

Which of the two future universe possibilities is more likely to happen?

Astronomers conclude that the universe will likely expand forever

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