Martian Wind Vane
What's the weather like on Mars's south pole? The answer is blowin' in the wind.
As seen in a picture released yesterday and taken by NASA's Mars Reconnaissance Orbiter, dark dust streaks point in several directions across the red planet's carbon dioxide ice cap. The seasonal ice cap slowly vanishes during Martian spring, and winds kick up dust from patches of exposed soil, creating elongated fans of material.
Watching which directions the fans point over time can help scientists decipher local weather conditions around the planet's pole.