Martian climate Archives

January 17, 2024January 17, 2024 by Evan Gough

Early Mars Climate was Complex, with Streams Flowing Intermittently for Millions of Years

This figure from new research shows an unnamed river valley network on Mars. By dating the craters in the image, a researcher at the Planetary Science Institute was able to determine when the river channels were formed. Image Credit: MOLA MEGDR, NASA/USGS; THEMIS mosaic, ASU/NASA/USGS; CTX, NASA/MSSS.

There’s overwhelming evidence that Mars was once wet and warm. Rivers flowed across its surface and carved intricate channel systems revealed by our orbiters. Expansive oceans even larger than Earth’s may have covered a third of its surface. Then something happened: Mars lost its atmosphere, cooled down, and surface water disappeared.

September 28, 2021September 29, 2021 by Matt Williams

How Much Carbon Dioxide Snow Falls Every Winter on Mars?

Mars’ south polar ice cap. Credit: ESA / DLR / FU Berlin /

Like Earth, Mars experiences climatic variations during the course of a year because of the obliquity of its rotational axis. This leads to the annual deposition/sublimation of the CO2 ice/snow, which results in the formation of the seasonal polar caps. Similarly, these variations in temperature result in interaction between the atmosphere and the polar ice caps, which has a seasonal effect on surface features.

On Mars, however, things work a little differently. In addition to water ice, a significant percentage of the Martian polar ice caps are made up of frozen carbon dioxide (“dry ice”). Recently, an international team of scientists used data from NASA’s Mars Global Surveyor (MGS) mission to measure how the planet’s polar ice caps grow and recede annually. Their results could provide new insights into how the Martian climate varies due to seasonal change.

November 13, 2019November 13, 2019 by Evan Gough

Mars 2020 Rover is Going to a Place on Mars That’s Perfect for Preserving Fossils

Jezero Crater on Mars. Lighter colors represent higher elevations. The Mars 2020 rover will investigate the "bathtub ring" of carbonates around the edge of the crater for microscopic fossils. The dark oval is the landing ellipse. Image NASA/MRO

Back in November 2018, NASA announced that the Mars 2020 rover would land in the Jezero Crater. Jezero Crater is a geologically diverse area, with an alluvial fan of sediment deposited by an incoming river. That sediment may contain preserved ancient organic molecules, and the deposit is clearly visible in satellite images of the Crater.

But the crater holds something else that has scientists intrigued, something that doesn’t show up so clearly in visible light images: a “bathtub ring” of carbonates, which scientists think could hold fossils.

April 1, 2019April 1, 2019 by Evan Gough

Rivers on Mars Flowed for More Than a Billion Years

A photo of a preserved river channel on Mars. The color is overlaid to show elevation, with blue being low and yellow being high elevation. Image Credit: NASA/JPL/Univ. Arizona/UChicago

The ancient climate of Mars is a mystery to scientists. Even with all we’ve learned about Mars, it’s still difficult to explain how lakes and rivers existed. A new study shows that Martian rivers were swollen with runoff and that they flowed far later into the planet’s history than previously thought.

The question is, how did the Martian climate create these conditions?