Mars is home to the highest clouds ever discovered above the surface of a planet, astronomers said today.
The European Space Agency’s orbiting Mars Express spacecraft found clouds that are between 50 and 62 miles (80 to 100 kilometers) above the red planet.
The highest clouds on Earth top out at about 52 miles (84 kilometers).
The surprising clouds are most likely made of carbon dioxide, researchers said. There were detected with a camera that senses ultraviolet and infrared light, so there is no conventional picture of them.
The clouds were spotted by observing distant stars just before they disappeared behind Mars. The stars would dim as they went behind clouds.