A team of scientists led by The Open University has discovered evidence of recent glacial meltwater on Mars, despite the widely-held view that the recent climate was too cold for ice to melt.

By Darry Khajehpour

Frances Butcher, lead author and PhD researcher.

Planetary scientists have discovered a rare ‘esker’ on Mars – a ridge of sediment deposited by meltwater flowing beneath a glacier in the relatively recent past (about 110 million years ago), despite cold climates.

With average temperatures on Mars of -55°C, it is widely thought that glaciers in the mid-latitudes – between the equator and the poles – are too cold to have produced meltwater. However, new research by the Open University (OU), in collaboration with University College Dublin, the University of Cambridge, and the University of Nantes*, suggests that, due to underground volcanic activity and heat generated by ice movements, the temperature beneath this specific mid-latitude glacier did rise enough to cause the ice to melt.

This meltwater then formed a tunnel, which filled with sediment and was left behind as a ridge, known as an esker, as the glacier retreated.

Frances Butcher, a PhD researcher in Planetary Science at The Open University and lead author of the paper published today in the Journal of Geophysical Research: Planets, a journal of the American Geophysical Union, said:

“Similar to Earth, Mars’ poles are covered in large, solid ice caps, and the equator doesn’t have any surface ice at all. The regions between the equator and the poles have thousands of water-ice glaciers that are similar to those found in mountainous regions on Earth.

“It was previously thought that mid-latitude glaciers on Mars had never produced liquid water, but eskers indicate that rare, localised melting has occurred beneath some of these glaciers in the recent past.”

Whilst there is no evidence that liquid water still exists under these glaciers today, the research gives important insights into environmental conditions that could have caused ice to melt in Mars’ recent geological history.’

An esker emerging from a glacier surface.
Image credit: Frances Butcher, NASA/JPL-Caltech/MSSS

“Until now, only one other esker had been discovered emerging from the front of a mid-latitude glacier,” Butcher said. “Both eskers formed between 110 – 150 million years ago, which is very recent for geologists, and are located in deep rift valleys, which could explain why these specific glaciers produced meltwater despite cold climates on Mars. Similar to some rift valleys on Earth, we think that heat from underground volcanic activity warmed the beds of the glaciers that flow within them causing ice to melt.”

If humans eventually travel to Mars, mid-latitude glaciers would be a relatively accessible source of ice that astronauts could process into water. Eskers could also provide sites of interest for scientific exploration close to these ice resources.

—  Darry Khajehpour is a member of the media relations team at The Open University. This post originally appeared as a press release from the OU website.