The seismometer on NASA’s InSight probe will continue to listen for Marsquakes even as other systems on the mission are forced to shut down due to low power levels.
The spacecraft has just detected a Magnitude 5 tremor, the largest event in the spacecraft’s three years on Mars.
However, InSight is now obtaining very little energy from its solar panels. Winter is approaching, and the arrays are covered in dust. Lower light levels will indicate the mission’s end.
The probe’s robotic arm, for example, is about to be locked in place and turned off.
For a while, the vital seismometer can be reduced to a reduced working mode, turning on for only part of a Martian day, or Sol, and then perhaps only every other day.
Mission managers will keep this going as long as they can, but they know time is running out.
“[In July], we anticipate turning off our seismometer, not because we want to, but because we don’t have the energy to run it,” said Kathya Zamora Garcia, InSight’s deputy project manager at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California.
“We do anticipate having to conclude all InSight operations at the end of the calendar year,” she told reporters.
The mission, which landed in the flat landscape of Elysium Planitia in 2018, has changed our understanding of Mars’ interior.
We had a “really fuzzy picture” of how Mars’ different layers were organized before its sophisticated French-UK seismometer package began returning data.
Scientists can now be much more certain about the thickness and composition of the planet’s crust, mantle, and core after using vibrations from over 1,300 Marsquakes to “image” the planet’s deep geology.
“What InSight has done is shine a light on the inside of Mars,” said Bruce Banerdt, principal investigator at JPL.
“Whereas we’ve known a lot about the outside of Mars for the last 50 years – we’ve taken images, spectra, and measurements of the surface of Mars – InSight is the first mission to shine a light beneath the surface of Mars and show us what the rest of the planet looks like.”
Scientists expected Martian dust to settle on InSight’s solar wings, blocking out the Sun’s rays.
All solar-powered missions to Mars must deal with this recurring scourge.
When InSight touched down on November 26, 2018, its black-colored, gleaming clear wings were producing around 5,000 Watt-hours per sol.
At around 500 Watt-hours per sol, they can only produce one-tenth as much today, colored red by all the dust.
“We use an electric oven as a marker to help people understand,” explained Zamora Garcia.
“So, when we first arrived, we had an hour and forty minutes to use an electric oven.
We could probably only run that for 10 minutes nowadays.”
inventive efforts have been made to clean the wings.
InSight has a scoop, and sprinkling dust on the wings had the effect of knocking off some of the dust that was already there.
The trick has been used six times successfully to extend operations, but it will not save the mission.
Scientists are hoping that InSight will be able to add a few more events to its total of 1,313 detected Marsquakes.
Who knows, they might even see another Magnitude 5 before the mission is terminated.
The M5 was discovered on Mars on the morning of May 4th.
For context, a tremor of that magnitude would be felt on Earth and could even cause minor damage to poorly constructed buildings.
The mission team is still analyzing the data, but they believe the Marsquake occurred near, but not exactly in, a region of the planet known as Cerberus Fossae.
Cerberus Fossae, about 1,500 kilometers east of InSight’s location, has been the source of all of the probe’s larger tremors.
Because of past volcanic activity on Mars, the terrain is heavily faulted.
For 1,000 kilometers, two massive parallel fissures run across the landscape.
The vast majority of Mars’ quakes are most likely caused by thermal anomalies in the crust.
As the planet cools and shrinks, its rocks will fracture along weak points, releasing the seismic waves that InSight’s seismometer was designed to detect.
“InSight has been an incredible mission for us, and it’s given us a glimpse of Mars that no other spacecraft in our Nasa Mars fleet could,” said Lori Glaze, director of Nasa’s planetary science division.
“Understanding Mars and studying its interior structure answers key questions about the early formation of our inner Solar System’s rocky planets, including Mercury, Venus, Earth, Earth’s Moon, and Mars, as well as helping us understand rocky [planets beyond our Solar System].”