The European Space Agency (ESA) reported today (February 6, 2012) that its Mars Express spacecraft has strong evidence for an ocean once covering part of Mars.
The spacecraft used radar to detect sediments reminiscent of an ocean floor within the boundaries of previously identified, ancient shorelines on Mars.
Jérémie Mouginot, Institut de Planétologie et d’Astrophysique de Grenoble (IPAG) and the University of California, Irvine, and colleagues have analysed more than two years of data and found that the northern plains are covered in low-density material. Dr. Mouginot said:
We interpret these as sedimentary deposits, maybe ice-rich. It is a strong new indication that there was once an ocean here.
The existence of oceans on ancient Mars has been suspected before and features reminiscent of shorelines have been tentatively identified in images from various spacecraft.
But a Mars ocean remains a controversial issue.