ESA’s Mars Express has captured images of one of the largest outflow channel networks on the Red Planet that seem to indicate the presence of a ‘mega flood’ around 3.6–3.4 billion years ago.
This find gives substantial proof to the claim that Mars was once an active, thriving ecosystem complete with rivers, oceans, rainfall, active volcanoes, and more.
The flood was believed to have occurred in the The Kasei Valles channel system.
The Kasei Valles channel system extends around 3000 km from its source region in Echus Chasma – which lies east of the bulging volcanic region Tharsis and just north of the Valles Marineris canyon system – to its sink in the vast plains of Chryse Planitia.
A combination of volcanism, tectonics, collapse and subsidence in the Tharsis region led to several massive groundwater releases from Echus Chasma, which subsequently flooded the Kasei Valles region around 3.6–3.4 billion years ago. These ancient mega-floods have left their mark on the features seen today.
Mars Express is a space exploration mission being conducted by the European Space Agency (ESA). The Mars Express mission is exploring the planet Mars, and is the first planetary mission attempted by the agency. “Express” originally referred to the speed and efficiency with which the spacecraft was designed and built. However “Express” also describes the spacecraft’s relatively short interplanetary voyage, a result of being launched when the orbits of Earth and Mars brought them closer than they had been in about 60,000 years.
The presence of certain formations on Mars’ craters (captured by Express) show signs of water erosion, similar to what we see here on Earth.
By contrast, the debris blanket surrounding the adjacent crater has remained intact. This suggests the impact producing that crater occurred after the major flooding.
Moreover, the appearance of the debris blanket tells a story on the nature of the subsurface: in this case it points to the floodplain being rich in water or water-ice.
Indeed, the pattern is reminiscent of a ‘splash’: the debris ejected from the crater was rich in water, allowing it to flow more easily. As it slowed, the debris behind it piled up, pushing up the material at its periphery into ramparts.