Titan is the only moon in the solar system with a dense atmosphere, which is mostly nitrogen like Earth's.

Venus is sometimes called Earth's sister planet.

Fact #309 · Space

A day on Mercury lasts longer than a year on Mercury.

Fact #102 · Space

Neutron stars are so dense that a single teaspoon would weigh billions of tons on Earth.

Fact #1848 · Space

Cosmic microwave background radiation is evidence of the early universe.

Fact #1608 · Space

The International Space Station orbits Earth every 90 minutes.

Fact #1539 · Space

The Moon's surface is covered in craters.

Fact #97 · Space

There are rogue planets drifting through space with no star at all.

Fact #1823 · Space

There are stars older than the Milky Way.

Fact #1697 · Space