Scientists have proven that Earth's mantle and the moon's mantle are made of the same substances.

People have felt "marsquakes" on the surface of Mars.

It is possible for spacecraft to bring materials from space back to Earth for study.

Satellite photos revealed that Jupiter has large gas belts on its north and south poles.

Spacecraft that landed on the surface of Pluto proved its mountains were made of water-ice.

The spacecraft New Horizons, launched in 1977, is now studying interstellar space.