The Mars Express spacecraft has sent back images that some are interpreting as the broken plates of a Martian sea, surviving in the form of pack ice. New Scientist is running the story, saying the sea appears to be about 800 by 900 kilometers in size and is found 5 degrees north of the Martian equator. From the story:

Images from the High Resolution Stereo Camera on Mars Express show raft-like ground structures – dubbed “plates” – that look similar to ice formations near Earth’s poles, according to an international team of scientists.

But the site of the plates, near the equator, means that sunlight should have melted any ice there. So the team suggests that a layer of volcanic ash, perhaps a few centimetres thick, may protect the structures.

We should have more on this tomorrow, since the leader of the research team, John Murray at the Open University, UK is supposed to present the findings at 1st Mars Express Science Conference in Noordwijk, the Netherlands, today.