Mars is a very different world today than it once was. Scientists believe the planet used to have a thicker atmosphere, liquid water on its surface, and a warmer environment. Now it is cold, dry, and surrounded by only a thin layer of gas.

The main force behind this dramatic change is the solar wind, a constant stream of charged particles flowing from the Sun. Over billions of years, this flow has steadily stripped away much of Mars’ atmosphere. As the atmosphere thinned, temperatures dropped and surface water gradually disappeared.

NASA’s ESCAPADE Mission Investigates Mars
To better understand this transformation, NASA launched the ESCAPADE (Escape and Plasma Acceleration and Dynamics Explorers) mission on November 13, 2025. Its scientific instruments were activated and fully operational as of February 25. These tools will study how Mars lost its atmosphere and how solar activity continues to affect the planet today. The mission will also collect new data on space weather near Earth and during the journey to Mars.

Once at Mars, the mission’s results could help NASA prepare for future human exploration by improving understanding of the planet’s harsh environment.

“The pioneering ESCAPADE duo will not only investigate the Sun’s role in transforming Mars into an uninhabitable planet, but also will help inform the development of space weather protocols for solar events directed at Mars during future human missions to the Red Planet,” said Joe Westlake, heliophysics division director at NASA Headquarters in Washington. “By joining the heliophysics fleet of missions across the solar system, ESCAPADE will be another weather station making humans and technology in space safer and more successful.”