July 5, 2012
Mars Express Finds Complex History On The Martian Surface
Lee Rannals for redOrbit.com - Your Universe Online
An image taken by the ESA's Mars Express has revealed an area on the Red Planet that has quite a complex history.The orbiter snapped a photo at the Melas Dorsa region on Mars on April 17 with its high-resolution stereo camera.
The area is found in the famous Valles Marineris canyon, and sits in the volcanic highlands of Mars between Sinai and Thaumasia Plana.
The image shows wrinkled ridges, some unusual intersecting faults, and an elliptical crater surrounded by ejecta in the shape of a butterfly.
Elliptical craters like the one seen in the image are formed when asteroids or comets strike the surface of the planet at a shallow angle, according to ESA.
Scientists believe that the fluidized ejecta pattern indicates the presence of subsurface ice, which melted during the impact.
These types of impacts have helped to create a number of smaller craters in the ejecta blanket, ESA said.
The rim of another crater is visible in the image as well, and the space agency said it appears mostly to have been buried during some distant epoch of volcanic dust and ash.
"This makes any detailed study of it almost impossible," according to ESA. "However, its center shows concentric deposits that could provide insights into the composition of the volcanic material that buried it."
The Mars Express image also shows several wrinkle ridges, which form when horizontal compression forces in the crust push the crust upwards.
The left side of the image shows the ridges bisected by crustal displacement faults. These have cut into the ridges and the surrounding surface. According to ESA, these ridges highlight the different tectonic phases responsible for the formation of the region.