Not So Warm After All
Chris Manktelow discusses research that sheds new light on Mars’ ancient past
If you look through a telescope at the Southern Highlands of Mars, you can see thousands of valleys cut into the red rock. Astronomers think that these valleys were carved by liquid water 3.5-3.9 billion years ago, which is needed to support life on Mars. This because all lifeforms that we know about use water to dissolve and carry chemicals between cells. However, computer simulations of the early Martian climate suggest that Mars was cold and icy like it is today. So, how did the liquid water get there when Mars was freezing cold?
How did liquid water get there when Mars was freezing cold?
To solve this problem, Anna Gau Galofre and her team at the University of British Columbia speculated that the valleys were formed by water that has melted under the pressure of an ice sheet. To test their hypothesis, they compared the valleys on Mars with the patterns of valleys on Earth that were carved by water that flows underneath ice sheets. They found that the patterns of valleys on Mars matched valleys on Earth that were once sculpted by water underneath ice sheets.
Patterns of valleys on Mars matched [those] that were once sculpted by water underneath ice sheets
The new theory explains the existence of the valleys and supports computer simulations of the early Martian climate. It also suggests that ancient Mars was not warm and wet with flowing rivers, but rather cold and icy. More research is needed to find out whether life could survive under Martian ice sheets like it does under the Antarctic Ice Sheet on Earth.