STOLEN BY THE SUN

So what happened to Mars’ ancient lakes and streams?

In November 2015, NASA’S MAVEN (Mars Atmosphere and Volatile Evolution Mission) orbiter revealed the answer: the solar wind blew away most of the atmosphere. Without its protective blanket, the planet’s water evaporated.

Dipping into the thin Martian atmosphere, just 1% as thick as Earth’s, MAVEN measured wisps of ionised gas streaming away from the planet at a rate of 100 grams per second. The rate increased 20fold when a solar storm struck. That’s shown in this simulated image: white streaks are the solar wind and the coloured streaks show the energy of escaping Martian gases. The hottest colours have the highest energy and are concentrated at the pole.

CREDIT: NASA’S SCIENTIFIC VISUALIZATION STUDIO / MAVEN SCIENCE TEAM