Space Facts for Kids

Laika, a stray dog from Moscow, became the first animal to orbit Earth in 1957.

Valles Marineris on Mars is the largest canyon in the solar system — it's as long as the entire United States.

A year on Mercury is only 88 Earth days because it orbits so close to the Sun.

Space officially begins at the Kármán line, only about 62 miles above Earth's surface.

A white dwarf star is so dense that a teaspoon of it would weigh about 5.5 tons.

Jupiter's moon Io is the most volcanically active body in the solar system, with over 400 active volcanoes.

The observable universe is about 93 billion light-years across, but it's still expanding.

There is a star called Lucy (BPM 37093) that is essentially a diamond the size of Earth.

Venus is the hottest planet in our solar system at around 900°F, even though Mercury is closer to the Sun.

Comets actually have two tails — one made of dust and one made of gas, pointing in slightly different directions.