'Mars may have a coastline like Greenland'

`Mars may have a coastline like Greenland` London: Early in its history, Mars may have a cold glacier-rimmed ocean covering its northern lowlands and its coastline may have resembled that of Greenland or Norway, according to a new study.

Scientists who conducted computer simulations of the Red Planet found that there was a big temperature difference between its warmer equatorial regions and the much colder poles four billion years ago.

As a result, they believe, any ocean in the northern lowlands would have been near-freezing, the Daily Mail reported.

Lead researcher Dr Alberto Fairen of NASA's Ames Research Centre at Moffett Field, California, said if at all a ocean existed in the Red Planet, it must have been very cold.

The researchers believe that a wall of glaciers skirting the ocean would have prevented the deposition of phyllosilicates originating in the equatorial highlands.

The minerals are associated with liquid water. Previously their absence in the Martian northern lowlands cast doubt on previous speculation that an ocean existed there.

Dr Fairen said: "We conclude that inefficient heat transport from the equator to the poles on early Mars, due to the absence of Earth-like equator-to-pole oceans, resulted in a steep latitudinal gradient of temperatures in both hemispheres, with warmer mid and equatorial areas, and glacial polar regions.

"As a consequence, if a northern ocean existed on early Mars, it was very cold. Glaciers rimming a cold northern ocean would have prevented a significant fluvial transport of phyllosilicate-rich materials from the highlands into the lowlands."

The study is published in the journal Nature Geoscience.