Sorrento Valley’s Malin Space Science Systems built cameras that captured the Petco Park-size result of a meteoroid strike
Liliya Posiolova, a researcher at Malin Space Science Systems, looks at photos of a Mars crater found in February. (Adriana Heldiz U-T)
By Gary Robbins
A big space rock traveling faster than the speed of sound struck Mars last Christmas Eve, producing a crater the size of San Diego’s Petco Park and ejecting rocks far and wide.
“The material traveled the distance between Petco and Cardiff,” said Liliya Posiolova, a researcher at Malin Space Science Systems, or MSSS, in Sorrento Valley. “When things settled down, glittering ice could be found in the ejecta.”
That’s not a theory. A spacecraft orbiting Mars located and photographed the crater in crisp detail using two cameras built by Malin. It was following commands from Posiolova, who was working a hunch.
A tiny, dying seismometer on the surface of Mars had recorded what was thought to be a magnitude 4.2 “Marsquake.” Could the vibrations have been caused by a meteoroid strike instead, she wondered?
Posiolova looked deeper. The answer was yes. It’s all explained in a recent issue of the journal Science and has caused a sensation among researchers who study the makeup and evolution of terrestrial bodies.
What Malin and NASA had discovered was the newest large planetary crater that is known to humans. They did so on Valentine’s Day, less than two full months after the rock hit Mars. And, in a bit of serendipity, they showed that a seismometer and an orbiting spacecraft can be jointly used to quickly pinpoint and photograph meteoroid strikes on distant planets.
The Malin photos also revealed that the exploding meteoroid — whose energy was possibly equivalent to 10 tons of TNT — ejected ice from just below the planet’s surface. The spot where it happened is the farthest point south in Mars’ northern hemisphere where ice is known to exist.
“The spot is close to the equator, and pretty large quantities of ice were ejected when this collision happened,” said Bruce Banerdt, NASA’s principal investigator on InSight, the seismometer instrument sitting on Mars.
“That water-ice is the single most important resource that astronauts will need on Mars. And this site is closer to the equator, where it is warmer and easier to land.”
NASA has said it wants to place astronauts on Mars in 2033. China has set the same goal.
The new discovery has burnished the reputation of Malin, a camera maker that has been drawing back the veil on the cosmos for decades.
“MSSS produced cameras for NASA’s Mars rovers, showing us vistas that make us feel like we’re standing on (the planet),” said Lisa Will, an astronomy professor at San Diego City College.
“Their camera on NASA’s Juno spacecraft has captured our closest views of Jupiter, with its intricate cloud patterns seen in more detail than ever before.
“MSSS cameras have provided some of the most beautiful and powerful images of our solar system.”
Risky business
Attempting to explore the cosmos with unmanned spacecraft can be humiliating work. About half of the roughly 50 Mars missions launched since 1960 have been complete or partial failures, including some spacecraft that carried Malin cameras.
None of the cameras the company has flown on nine Mars missions have failed in their assigned duties.
“It’s just us trying very hard to avoid failure and having a certain amount of good luck,” Michael Ravine, Malin’s advanced projects manager, told The San Diego Union-Tribune in 2020, shortly before NASA successfully sent the Perseverance rover to Mars.
“We hope our luck continues. But again, who knows?”
There’s a lot of upside when things click, as proved by the Mars Reconnaissance Orbiter, which began circling the red planet in 2006. Two of its three cameras were built by Malin.
The orbiter has revolutionized scientists’ thinking about Mars, especially its history of water. The spacecraft also has shown that such things as lava flows and wind erosion have shaped the landscape in much the same way they have on Earth.
More recently, NASA successfully placed the InSight lander on Mars. It’s the size of a compact car and features a highly sensitive seismometer. Scientists believe it is as important to understand what’s occurring beneath the crust as it is to study the planet’s surface.
Unlike Earth, Mars does not feature large tectonic plates. But various forces produce seismic activity — or Marsquakes. To explore what’s going on, NASA placed InSight near Mars’ equator in late 2018, where it has recorded more than 1,000 quakes. The data helps scientists create 3D models of Mars’ interior.
Most of the Marsquakes it records are small. But on Christmas Eve, InSight recorded one of the largest seismic events it had seen. That fascinated the NASA InSight team, which decided that it was likely looking at a big Marsquake. They notified their collaborators, including Posiolova at Malin, a company with only 91 employees.
The true nature of the shaking didn’t become apparent until later, and it was largely by accident. On Feb. 11, Posiolova used the orbiter to photograph an area about 2,000 miles northeast of InSight. She had taken images of the same site about two years earlier.
This time, the photos showed something new and remarkable — a big crater with a large ejecta field. She closely inspected the images on Valentine’s Day and, before long, remembered that InSight had sent an email at Christmas talking about a large seismic event.
Further study revealed that InSight hadn’t recorded a quake. It had captured the moment a meteoroid had slammed into the planet.
“Even though we do not have a movie of the impact, we can piece together a lot of what happened,” said Posiolova, who was born and raised in the Soviet Union.
“If there had been observers at (the site), they would have seen, just after sunset, a fireball screaming through the sky from the southwest-to-northeast and then an explosion, followed by lots of debris (with ice) raining down.”
The information it produced “is very likely to remain a unique data set for (a) decade, unique for understanding how an impact released its energy in the atmosphere and subsurface,” said Philippe Lognonné of the University of Paris, another investigator on the InSight mission.
Unfortunately, InSight won’t be around much longer to help. Dust is piling up on its solar panels, cutting off its energy supply.
“Don’t say it’s dying,” said Banerdt. “Say it’s going into retirement.”
As for Posiolova, life, and work, go on.
“I tell people, ‘Every day I go to work on Mars,’ ” she said. “I wonder what we’ll find next.”
gary.robbins@sduniontribune.com
