Earth Science, Observing Space, Galaxies, Big Bang Theory

Front

What is the universe?

Back

The universe includes all matter, space, energy, and time. It is everything that exists.

Front

How many galaxies are estimated to be in the universe?

Back

Astronomers estimate that the universe contains billions of galaxies.

Front

What event do cosmologists believe marked the beginning of the universe?

Back

The Big Bang.

Front

Approximately how long ago did the Big Bang occur?

Back

13 to 14 billion years ago.

Front

What is the correct order of cosmic structures from largest to smallest?

Back

Universe, Galaxy, Solar System, Sun, Earth.

Front

What is gravity?

Back

Gravity is the attractive force that exists between all objects, creating stars, planets, solar systems, and galaxies.

Front

What is a galaxy?

Back

A galaxy is a massive system that consists of stars, stellar remnants, interstellar gas, dust, and dark matter, bound together by gravity.

Front

What is the Milky Way?

Back

The Milky Way is the galaxy that contains our solar system.

Front

What is a solar system?

Back

A solar system is a collection of celestial bodies, including a star and the objects that orbit it, such as planets, moons, asteroids, and comets.

Front

What is a nebula?

Back

A nebula is a giant cloud of dust and gas in space, often the birthplace of stars.