Space Facts for Kids
Out-of-this-world facts about the universe
The Milky Way and the Andromeda galaxy are on a collision course and will merge in about 4.5 billion years, but the stars are so far apart that very few will actually collide.
Neutron stars are so dense that a teaspoon of neutron-star material would weigh about one billion tonnes — as much as all the humans on Earth combined.
The first woman in space was Soviet cosmonaut Valentina Tereshkova, who orbited Earth 48 times in June 1963 — nearly two years before the first American spacewalk.
Jupiter's moon Io is the most volcanically active world in the solar system, with hundreds of active volcanoes — some shooting sulphur plumes 500 kilometres high.
Jupiter's moon Europa has a vast saltwater ocean beneath its icy surface, estimated to contain twice as much water as all of Earth's oceans combined.
Jupiter has the shortest day of any planet in the solar system — it rotates so fast that a day on Jupiter lasts only about 10 hours.
In about 5 billion years, the Sun will expand into a red giant large enough to swallow Mercury, Venus, and possibly Earth, before shrinking into a white dwarf.
NASA's Voyager 1 spacecraft, launched in 1977, left our solar system in 2012 and is now the most distant human-made object ever, travelling through interstellar space.
The asteroid Kleopatra is shaped like a dog bone and is about 270 kilometres long. It orbits the Sun between Mars and Jupiter and even has its own two tiny moons.
Saturn has the most moons of any planet in our solar system, with over 140 confirmed moons — including Titan, which has lakes of liquid methane.