The Inside of Mars Is ‘Surprisingly Soft’, A New Survey Says

Astronomers are once again turning their attention to the red planet and how the planet is made. A study out of Northwestern University and published in the journal Nature on Wednesday recapped two surveys into the layers and core of Mars, looking for signs of systemic activity and examining the planet’s deep composition.

According to the report, both studies conclude that the liquid iron-nickel core of Mars is surrounded by an approximately 150-kilometer or 93 miles-thick layer of "soft, essentially molten rock."

“This could be a sign that Mars had a turbulent interior following its formation, rather than a calmer one that more gently transported and shed heat to interplanetary space,” lead author Suzan Van Der Lee wrote in the Nature paper, titled "Mars is Surprisingly Soft."

As part of NASA’s InSight rover mission launched in 2018, researchers conducted seismological studies on the interior of Mars’ crust for three years that collected data on “marsquakes” and the effects of meteorite impacts.

“The original intention was to learn more about the formation and evolution of Mars as a planet,” Van Der Lee, Professor and Director of Computing at Northwestern University, told Decrypt. “Doing that in a way that we've done for Earth very successfully is by listening to the planet.”

As Van Der Lee explained, the InSight rover examined Mars using sensory inputs, including visual, auditory, and physical contact.

“We can learn a lot because seismic waves can travel from one end of the planet to the other and collect information on the materials they traveled through,” Van Der Lee said.

Researchers can get a snapshot of the internal structure of a planet, which is a proxy for the overall state of the planet, Van Der Lee said. For example, the temperature of the planet and the composition of the different layers can reveal how the planet might have formed and the future of the planet.

Van Der Lee said that while quakes are present on Mars, they are less frequent than what occurs on Earth and should not hamper surface exploration of Mars once humans land on the planet.

“‘Marsquakes’ are less frequent and smaller in magnitude,” Van Der Lee explained. “So they're not necessarily a hazard if we wanted to do anything on the surface of Mars.”

Based in Illinois, Northwestern University has focused heavily on exploring the galaxy. Last week, a group of scientists and astronomers out of the university announced that they successfully used artificial intelligence and machine learning to identify and classify supernovae as they happen.

When asked about all of the experiments on and around Mars, Van Der Lee said she is not concerned about the potential of leaving behind space junk.

“All of the rovers on the surface of Mars are very sophisticated machines or instruments,” she said. “If the rovers are not revised, the parts can be useful for other things that humans might want to build.”

The issue of what to do with space junk has become a concern for policymakers. Earlier this month, Dish Network was fined $150,000 by the U.S. Federal Communications Commission for failing to move an old EchoStar-7 satellite away from others still in use. According to a BBC report, Dish Network admitted liability and agreed to a compliance plan.

While science fiction has played a significant role in our fascination with the red planet, Van Der Lee says the fascination with Mars also touches on our desire to know if we are truly alone in the universe.

“There have definitely been a lot of missions to Mars that have wanted to look for signs of life, either current life or early life early in Mars’ history, that has not been successful so far,” Van Der Lee said. “But that was one of the reasons why we've been fascinated with Mars.”

“It's pretty clear that it's hard for life to live on other planets, and Mars looked like the most reasonable alternative to Earth,” Van Der Lee said. “But compared to Earth, [Mars] is far removed from the paradise that Earth is for human life.”