Astronomers have found the fastest spinning star ever discovered. The hot blue giant rotates at one million miles per hour, or 100 times faster than our sun.
Orbiting spacecraft have now seen avalanches of dust on the surface of the planet Mars. Martian avalanches and quakes might be caused by meteor airbursts.
Some Martian gullies at the poles might have formed when a seasonal accumulation of carbon dioxide frost sublimed - turned directly from a solid to a gas.