An orbiting European probe just took a photo of two deep blue areas on Mar’s surface. Though they may look like lakes made of water, they probably aren’t. They’re actually patches of layered dark volcanic rock that only looks blue on the European Space Agency’s Mars Express spacecraft.
There have been many recent “blue” photos from mars, such as a blue sunset or blue auroras.
Scientists say that this is because of dark sediments being blown across Mars. The blue is simply an artifact or an illusion from image processing, according to the ESA.
“The blue-hued patches lying within the ragged craters are actually dark sediments that have built up over time,” the ESA added.
According to the ESA, the wind on Mars can blow so hard—100 km/h or 62 mph to be exact—that the dust storms these winds create can last up to weeks. With winds these strong, the erosion of Mar’s surface features should come as no surprise, even if it takes millions of years for it such things to happen.
While the images aren’t proof of water by any stretch of the imagination, early data from NASA’s Curiosity rover does indicate that Mar’s was once a wet planet and might have been capable of hosting microbial life.