A green glow has appeared around Mars

The Mars Trace Gas Orbiter spotted a phenomenon on Mars that has also been observed around Earth. A green glow outlining the planet is the result of charged oxygen atoms gradually calming down. The observations offer clues as to the thickness of the Martian atmosphere, which is important when sending missions to the planet's surface. Mars is known as the Red Planet due to its coppery hue. It's a dry, dusty, windy place, but that wasn't always the case. The planet was once very, very wet, with va...