Mars Express evidence for large aquifers on early Mars   A HRSC 3D perspective view of Candor Chasma (in false colours) characterised by the infrared images of OMEGA. It shows bright and brown deposits (red markers) that are rich in the mineral kieserite, a hydrated magnesium sulphate.   In this HRSC 3D perspective view of the Marwth Vallis area (shades of grey), OMEGA has mapped the water-rich minerals (blue). No hydrated minerals or sediments have been detected, either in the channel or in its opening. However, the outflow was so violent as to erode and expose ancient hydrated clay-rich minerals, tracing an early era when water was present.   The OMEGA instrument on Mars Express has shown that the violent outflows that sculpted the Marwth Vallis on Mars did not form nor flood with hydrated minerals (left). However, their erosion exposed ancient terrains in which hydrated clay minerals were detected, which trace back an early era with liquid water (right). Release date: 30 November 2005