A moon rock brought back over 50 years ago by the Apollo 17 mission has been connected with the birth of the Sea of Serenity — if true, it means the lunar mare formed hundreds of millions of years earlier than thought.
Mars, often called the Red Planet due to its rusty iron oxide covered surface, is Earth's smaller, colder neighbour. Orbiting the Sun at an average distance of 228 million kilometres, Mars shares remarkable similarities with Earth; a 24.6 hour day, polar ice caps, seasons driven by a 25.2 degree axial tilt, and evidence of ancient rivers and lakes that once flowed across its surface. Yet Mars today is a harsh world with a thin atmosphere just 1% the density of Earth's, average temperatures of -63°C, and no liquid water on its surface. It has an incredibly thin atmosphere composed primarily of carbon dioxide (95%) which is so tenuous that liquid water cannot exist on the surface, yet it’s still thick enough to generate global dust storms.

