Space Review

The Big Bang

Orbits

The Planets

Scale

Stars

100

This event, which occurred about 13.8 billion years ago, is believed to have marked the beginning of the universe.

What is the Big Bang?

100

This force, which attracts objects towards each other, is responsible for keeping planets in orbit around the sun.

What is Gravity?

100

This planet is the closest to the sun and has a surface temperature that can reach over 800°F.

What is Mercury?

100

These two planets are the closest in size to each other.

What are Venus and Earth?

100

Our star is this color and size.

Yellow, small/medium.

200

Edwin Hubble first proposed that galaxies are _, supporting the theory of the Big Bang.

What is "moving away from each other"?

200

The path a planet takes around the sun is known as this.

What is an orbit?

200

This planet is closest in size to Earth.

What is Venus?

200

This is the smallest planet.

What is Mercury?

200

When our star reaches the end of its main sequence, it will become this.

What is a red giant?

300

The Big Bang Theory suggests the universe began as this.

What is a single point?

300

According to this scientist’s law, the force of gravity decreases as the distance between two objects increases.

Who is Newton?

300

These four planets are rocky and closest to the Sun.

What are Mercury, Venus, Earth, and Mars?

300

This is the largest planet.

What is Jupiter?

300

Very large stars, at the end of their main sequence, may explode into this.

What is a supernova?

400

This is how long it took for the first light to shine in the universe.

What is 300,000 years?

400

According to Einstein, orbits are circular because heavy objects do what to space?

What is stretch or warp it?

400

These four, Jovian, planets are largest and farthest from the Sun.

What are Jupiter, Saturn, Uranus, and Neptune?

400

List the planets in order from closest to farthest from the Sun.

Mercury

Venus

Earth

Mars

Jupiter

Saturn

Uranus

Neptune

400

If a star is large enough, it will eventually create this, a space so dense even light can't escape it.

What is a black hole?

500

This element, making up about 75% of the observable universe, was one of the first to form after the Big Bang.

What is hydrogen?

500

This is something that will eventually happen to a planet in orbit if its momentum isn't perfectly balanced with the force of gravity.

What is...

1. It will collide with the Sun.

2. It will escape from the Sun's gravity.

500

These two planets are the true "gas giants", since they are the largest and mostly made of hydrogen gas.

What are Jupiter and Saturn?

500

List the planets in size order, from largest to smallest.