Understanding Mars’s Surface as Perseverance Makes Contact

unmanned mars missions require carefully picked landing spots

By Jonny Lupsha, Wondrium Staff Writer

Mars makes for fascinating study, if a rover can traverse it. NASA’s Perseverance has done just that and sent back pictures and audio as proof. The first step is sticking the landing in a spot with a view.

Mars landscape
Photo By Dotted Yeti / Shutterstock

As space exploration continues, it grows increasingly bolder. In 2020, three unmanned missions to Mars left Earth from China, the United Arab Emirates, and the United States, respectively. China’s Tianwen-1, the UAE’s Hope Orbiter, and the U.S.’s Perseverance have all recently completed their journeys to the red planet.

Tianwen-1 makes use of an orbiter, a lander, and a rover for its exploration. The Hope Orbiter, as its name implies, has begun to orbit Mars for study and will continue to do so. Perseverance, meanwhile, has just landed and begun to roam the surface.

While the Hope Orbiter maintains a safe distance from Mars’s surface, Tianwen-1 and Perseverance each made careful landings on planned locations to explore the planet up close. Intimate knowledge of the planet’s surface was required.

Maybe Mars Needs Guardrails

What should the United States and China look for in a landing site? In her video series, A Field Guide to the Planets, Dr. Sabine Stanley, a Bloomberg Distinguished Professor in the Morton K. Blaustein Department of Earth and Planetary Sciences at Johns Hopkins University, shed light on the subject.

Choosing a site for a Mars rover or lander is quite involved,” she said. “You have to balance finding a scientifically interesting place to land with a relatively safe place to land. In terms of safety, you want a place that’s relatively flat and doesn’t have too many rocks or boulders that may cause the lander to tip over while landing.”

Dr. Stanley also said that one area of Mars, known as Chryse Planitia or “Plains of Gold,” was first explored by the landing craft Viking 1 in summer 1976. Viking 1 was also the first spacecraft to land on the surface of another planet. Chryse Planitia is believed to be a large impact crater through which water flowed long ago. One of its outflow channels was visited by the rover Pathfinder more than 20 years later, also thanks to having a “safe but interesting” landing area.

Other Craters of Interest

On the other side of Mars from Chryse Planitia, Viking 2 landed in Utopia Planitia, a 2,000-mile wide crater. Viking 2 touched down two months after its twin to find a rocky surface that was covered in frost every morning. Dr. Stanley described its terrain as “scalloped.”

“The scallops are believed to be formed when subsurface water ice sublimates during sudden exposure to the low pressures of the surface—for example, if a small impactor hits,” she said. “In 2016, ground-penetrating radar from the Mars Reconnaissance Orbiter provided further evidence for water in the subsurface of Utopia Planitia, perhaps as much as the volume of water in Lake Superior here on Earth.”

Past rovers that have explored two other craters—Gusev Crater and Gale Crater—each found evidence of ancient waterways as well. Each crater is about 100 miles in diameter, which is far more typical in size than Utopia Planitia. They were explored by the rovers Spirit and Curiosity in 2004 and 2012, respectively.

Perseverance and Tianwen-1 only just arrived on Mars, but—with their carefully chosen sites of exploration—their findings should bring further tales from the Red Planet back to Earth soon.

Edited by Angela Shoemaker, Wondrium Daily