The landing of NASA Perseverance Mars Rover next month it will make serious waves, some of which may help scientists better understand the structure of the Red Planet.
Perseverance, the centerpiece of NASA’s $ 2.7 billion life-threatening Mars 2020 mission, is expected to hit the 28-kilometer (45 km) Jezero crater on February 18. The epic landing will yield seismic signals to one of the rover’s cousins, NASA InSight Mars Lander, will try to track more than 3,200 kilometers, reports a new study.
If that happens, it will first be a spaceflight: no spacecraft has ever “heard” such a landing on another planet in this way, InSight team members said.
Pictured: NASA’s Mars Perseverance Rover mission to the Red Planet
InSight’s supersensitive seismometer package recorded hundreds of marsquakes since landing in November 2018 on a Mars plain known as Elysium Planitia. InSight team members use these measurements to map the interior of the Red Planet in unprecedented detail, the main purpose of the mission.
However, such interpretive work can be tricky.
“Unlike on earth, where you can independently find out when and where a [seismic] source happened, and of course how big it was, to March“We have a single station, and we’re both trying to identify the mechanics of the source and the structure of the planet through which the waves propagate,” said InSight lead author and team member Ben Fernando, a Ph.D. student at the University of Oxford in England, told Space.com.
“Disconnecting the two from each other is not necessarily trivial,” he added. “In the simplest explanation, if you were in a room and you could not see, it is difficult to see if someone is talking loudly from there or is quiet near you. And besides, if you do not know what the shape of the room, it would be even harder. ‘
The landing of perseverance is therefore a wonderful opportunity for InSight scientists – a chance to collect an impact-generated seismic data, the details of which are known in advance, Fernando and his colleagues write in the new study.
A good chance
March 2020 will use the same strategy for entry, descent and landing (EDL) that its predecessor, the Curiosity Mars Rover, safe in August 2012.
March 2020 will drop the pen Mars atmosphere hardens, friction is significantly delayed and then uses a supersonic parachute to slow down further. About seven minutes after atmospheric entry, a rocket-propelled crane will lower your endurance on Jezero’s floor on cables, then fly to intentionally land a safe distance away.
That last step will not yield seismic waves of significant force. According to Fernando and his team, two other points during the EDL series are likely to deliver relatively powerful signals.
One such signal will be generated by a sonic surge, which will occur after Mars 2020 arrives within about 100 km of the Martian surface, an altitude at which the atmosphere is dense enough “to find significant compression,” he said. the researchers said. wrote in the new study.
Some of the energy of this tree – which will disappear when the spacecraft is subsonic, about three minutes before contact – will hit the surface of Mars and be converted into seismic waves. But this signal will not be strong enough to be picked up by InSight, which is about 3,452km from Perseverance’s landing site, Fernando and his team calculated, citing the destructive effect of Marswinde as an important factor.
The other signal will come through a real impact on the surface – in fact double impacts. Shortly after Mars 2020 hits the atmosphere, the spacecraft will emit two “Cruise Mass Balance Devices” (CMBDs) to change the center of mass. The CMBDs, each weighing 170 pounds. (77 kilograms), will be dropped from a very high altitude, at an altitude of about 1450 km (1400 km / h), and will hit the ground at an estimated speed of 1400 km / h (14,000 km / h), said Fernando.
Mars InSight in Photos: NASA’s Mission to Investigate Mars’ Core
It is unclear how strong the seismic waves of the CMBD impact will be; InSight has not yet detected any confirmed impact on Mars, so predictions are difficult. But Fernando and his team generated estimates based on data collected here on earth the moon, and the numbers indicate that InSight has a decent chance of measuring the waves.
“In the realistic best case (and assuming identical weather and noise spectra in the same period as one Mars year before), the required signal-to-noise ratio would be sufficient for a positive detection of 40% of the time,” wrote the researchers. in the new study, which was submitted to (but not yet accepted) the journal Earth and Space Sciences. You can read a free preview of it here.
There’s a bit of luck with this relatively rosy figure: the CMBD-generated waves will arrive at InSight’s location early in the Elysium Planitia time, the quietest part of the day, Fernando said.
A detection will be a pretty big deal for InSight team members. They would know exactly how far and how fast the seismic waves are moving.
“If you know how fast it went, you can start working out what the structures were that they propagated through,” Fernando said.
Perseverance incidentally wants to document his own landing in an unprecedented way. March 2020 has two microphones, one of which tries captures the dramatic sounds of EDL on February 18th. (The other is part of Perseverance’s wobbly SuperCam system.) No Mars spacecraft has ever successfully picked up the raw sounds of the Red Planet.
Other landings?
Perseverance is not the only spacecraft that will land on Mars this year. China’s The Tianwen-1 mission will arrive in orbit on February 10 and drop a lander and rover on the Red Planet about two months later, if all goes according to plan.
The InSight team would like to listen to the landing in Tianwen-1, Fernando said. But details about the mission – specifically the exact landing time and location – are difficult to obtain, so ‘making predictions about the traceability of this signal is not possible’, the researchers wrote in the newspaper.
The Euro-Russian ExoMars program launches a lander-rover duo to Mars in 2022. InSight will almost certainly not be able to detect seismic signals from the landing series, as the ExoMars duo will hit the other side of the planet from InSight, Fernando said.
SpaceX plans to fly to Mars soon with the next generation spaceship – maybe already in 2024, said the company’s founder and CEO, Elon Musk. If InSight lives long enough, it might document the touch of one or more of this spacious 50-foot stainless steel 165-foot-long spacecraft.
“It’s not out of the question,” Fernando said. “It just depends on where they decide to land.”
Mike Wall is the author of “Out there“(Grand Central Publishing, 2018; illustrated by Karl Tate), a book about the search for alien life. Follow him on Twitter @michaeldwall. Follow us on Twitter @Spacedotcom or Facebook.