A shadowy presence is spreading across the surface of Mars.<\/p>\n
New images released by the European Space Agency<\/a> that were taken by its Mars Express orbiter show a rapid transformation taking place in the planet\u2019s Utopia Planitia basin, which scientists believe was once the site of an ancient ocean.<\/p>\n Today, it\u2019s a veritable battleground between the forces of light and dark.<\/p>\n That\u2019s only being slightly hyperbolic. In one half of a composite image taken with the mission\u2019s High Resolution Stereo Camera is the Red Planet\u2019s traditionally light colored, sandy beige surface. In the other half, the landscape is a dark reddish-brown, as if corrupted by a horrific blight.<\/p>\n Mars Express has captured a blanket of dark ash creeping across the Red Planet.<\/p>\n It has spread hundreds of kilometres in less than 50 years.<\/p>\n 1\/4 pic.twitter.com\/vxz8cIvsGM<\/a><\/p>\n \u2014 ESA Science (@esascience) April 15, 2026<\/a><\/p>\n Planetary scientists are still piecing together what\u2019s behind the unusual phenomenon. They suggest the dark presence could be volcanic ash deposited by martian winds. Alternatively, said winds could be blowing away ochre-colored dust that covered the blanket of ash.<\/p>\n According to the ESA, the material is made of what\u2019s known as mafic minerals that formed at high temperatures, such as olivine and pyroxene.<\/p>\n Like Earth, Mars is a volcanic world and is host to the largest volcano in the entire solar system, Olympus Mons, which towers nearly 14 miles above the surrounding landscape, with a base around the size of the state of Arizona. Whether volcanic activity still takes place on Mars, which has long, and now contentiously<\/a>, been considered a geologically \u201cdead\u201d world, is a matter of ongoing debate. But its rich volcanic history is plain to see<\/a> \u2014 and possibly still coloring the planet\u2019s surface.<\/p>\n If the darkening blanket is caused by spreading ash, it would be moving at a breakneck pace. A side-by-side of images taken by NASA\u2019s Viking orbiters in 1976 and the new ones from Mars Express show the dark patch growing significantly in the fifty intervening years. That\u2019s orders of magnitude quicker than other noticeable visual changes on the Martian surface, which can take place across millions of years, according to the ESA.<\/p>\n More on Mars: NASA\u2019s Mars Rover Comes Across Formation That Looks Like the Scales of a Massive Cosmic Reptile<\/a><\/p>\n