A study by a University of Chicago scientist deepens mysteries about the early Mars weather.
Mars once had red rivers. The history of past rivers, streams, and lakes is still evident today. But three billion years ago, they all dried up — and nobody knows why.
“People have come up with incredible ideas, but we’re not sure what caused the climate to change so dramatically,” said University of Chicago geophysical scientist Edwin Kite. “We would really like to understand, especially since the only planet we know so well has changed into a human habitation.”
Kite is the author of a new study examining the tracks of the Martian rivers to see what they can reveal about the planet’s water and atmosphere.
Many scientists once thought that the loss of carbon dioxide in the atmosphere, which helped keep Mars warm, caused this problem. But findings from a new study, published May 25, 2022, in the journal Science Advances, suggest that this change was caused by the loss of another vital ingredient that kept the planet warm enough to receive running water.
But we still do not know what it is.
Water, water everywhere — and not just a drop of water
In 1972, scientists were surprised to see images of NASA’s Mariner 9 mission as it orbited Mars off the orbit. Photographs reveal the location of rivers — a testimony to the fact that the planet once had a body of water, although it is as dry as a bone today.
Since Mars has no tectonic plates to change and dig over the rock over time, ancient river tracks are still lying on the surface as evidence quickly discarded.
This allowed Kite and his collaborators, including University of Chicago graduate student Bowen Fan and scientists from the Smithsonian Institution, Planetary Science Institute, California Institute of Technology Jet Propulsion Laboratory, and Aeolis Research, to analyze maps based on thousands of orbit satellite images. Based on the scattered tracks and the weather, the team has compiled a timeline of how river work has changed in altitude and latitude over billions of years.
Then they can combine that with the simulations of different weather conditions and see which one fits best.