Particle physics laboratory

Scientists imagine what Mars would look like as an exoplanet


Artist’s impression of a system of exoplanets escaping from the atmosphere in relation to its host star. Credit: MACH Center / Aurore Simonnet

In science fiction movies and TV shows, real locations on Earth, such as California’s Redwood National Forest and the Sahara Desert, have long been used to represent alien worlds. But recently in a Star trek-style twist, a group of scientists, including researchers from the Atmospheric and Space Physics Laboratory (LASP) at the University of Colorado Boulder, used a planet in our own backyard – Mars – to help characterize and identify habitable Earth – like the planets of other solar systems.

An international multidisciplinary team of modelers, observational scientists, and theorists from three scientific disciplines (space physics, planetary science, and astrophysics) worked synergistically to extrapolate their current understanding of Mars to determine which planets beyond the solar system of the Earth are the most likely to harbor life. The answer depends on the atmospheres of the exoplanets and what it takes for each planet to retain those atmospheres, including Mars if it revolved around a different star.

One example the team is studying is the case of “Exoplanet Mars” orbiting a dark M-class star, which is only about 4% as bright as our sun and nearly 3% cooler. 000 degrees Celsius. This research will provide a better understanding of how long a planet like Mars could retain an atmosphere if it revolved around this smaller, cooler but more active star. Preliminary results indicate that the rate at which the exoplanet Mars would lose its atmosphere would be greater than what the real planet experienced.

“Mars is a remarkable natural experiment that demonstrates how its atmosphere and, therefore, its habitability can be affected by the properties of the planet and the star on which it orbits,” said David Brain, LASP planetary researcher and chief of the team. The challenge, he added, is to bring together the expertise, observations and results of the model to understand the relative importance of each property, with the aim of making predictions about the habitability of individual planets in orbit. around other stars.

Artist’s conception of the atmospheric escape processes of Mars assuming it revolves around an M-class star. Credit: MACH Center / Cameron Pazol

This multidisciplinary and cutting-edge approach is made possible by the new Magnetic fields, atmosphere and connection to habitability (MACH) NASA DRIVE Science Center, run by Brain. DRIVE Science Centers (DSC) are part of NASA’s integrated multi-agency initiative to meet the objectives of the Grand Challenge.

“Our center has brought together experts from many scientific disciplines to collaboratively address broad issues such as the habitability of alien planets,” Brain said.

It is not always easy to organize scientists from many different disciplines. Brain said team members had to learn to communicate more effectively and understand how to fuse patterns developed by scientists in disciplines that had diverged from each other over the past decades.

“Together, we figure out what physics is important to include and how to tie the models together, while making sure team members feel heard and included in the process,” Brain explained.

The importance of this work was underscored just a few weeks ago, when the National Academies of Science, Engineering and Medicine named “Pathways to Habitable Worlds” as one of the three key areas for them. future research in their “Discovery paths in astronomy and astrophysics for the 2020s”(Astro2020) report.

“The fact that the astronomical and astrophysical community has highlighted this topic for the next decade is very exciting and a testament to the importance of our work,” said Brain.

David Brain will be presenting some The MACH team preliminary results this week at the AGU Fall Meeting 2021 in New Orleans.

The international MACH DSC team includes researchers from LASP and CU Boulder, University of Massachusetts, University of Kansas, NASA Goddard Space Flight Center, University of New Hampshire, LATMOS, University of California, Los Angeles, Sonoma State University, SRI International, University of Tokyo, University Leiden, Swedish Institute for Space Physics, Tohoku University and University of Illinois.