The ancient Greeks called our galaxy the Milky Way because they thought it was made from drops of milk from the breasts of the Greek goddess Hera.

Yuri Gagarin survived the first manned spaceflight but was killed in a plane crash seven years later.

Astronauts become a little taller in space. There is less gravity, so their bones are less squashed together.

Astronauts' footprints and Lunar Rover tyre tracks will stay on the moon for millions of years as there is no wind to blow them away.

About 1500 stars are visible at night with the naked eye in a clear, dark sky. There are 88 constellations altogether. The smallest star measures about 1700 km across. It is a white dwarf called LP 327-16.

The first object to orbit earth was Sputnik 1, launched by the USSR in October 1957.

The first animal in space was the Soviet dog, Laika, in November 1957. It died on the flight.

The first animals to survive in orbital spaceflight were the Soviet dogs, Strelka and Belka, launched in Sputnik 5 in August 1960.

The first person to orbit earth was Yuri Gagarin, from the USSR, in April 1961.

The first American to orbit earth was John Glenn in February 1962.

The first woman in space was Valentina Tereshkova, from the USSR, in June 1963.

The first person to walk on the moon was Neil Armstrong in July 1969.