ASTRONOMY PICTURE

OF THE DAY

EXPLANATION

Why would the surface of Titan light up with a blinding flash? The reason: a sunglint from liquid seas. Saturn’s moon Titan has numerous smooth lakes of methane that, when the angle is right, reflect sunlight as if they were mirrors. Pictured here in false-color, the robotic Cassini spacecraft orbiting Saturn imaged the cloud-covered Titan last summer in different bands of cloud-piercing infrared light. This specular reflection was so bright it saturated one of Cassini’s infrared cameras. Although the sunglint was annoying—it was also useful. The reflecting regions confirm that northern Titan houses a wide and complex array of seas with a geometry that indicates periods of significant evaporation. During its numerous passes of our Solar System’s most mysterious moon, Cassini has revealed Titan to be a world with active weather—including times when it rains a liquefied version of natural gas.

Image Credit

VIMS Team, U. Arizona, ESA, NASA