The agency’s lander felt the ground shake during the impact while cameras
aboard the Mars Reconnaissance Orbiter spotted the yawning new crater from
space.
NASA’s InSight lander recorded a magnitude 4 marsquake last Dec. 24, but
scientists learned only later the cause of that quake: a meteoroid strike estimated
to be one of the biggest seen on Mars since NASA began exploring the cosmos.
What’s more, the meteoroid excavated boulder-size chunks of ice buried closer
to the Martian equator than ever found before – a discovery with implications
for NASA’s future plans to send astronauts to the Red Planet.
Scientists determined the quake resulted from a meteoroid impact when they
looked at before-and-after images from NASA’s Mars Reconnaissance Orbiter (MRO) and spotted a new,
yawning crater. Offering a rare opportunity to see how a large impact shook the
ground on Mars, the event and its effects are detailed in two papers published
Thursday, Oct. 27, in the journal Science.
The impact crater, formed Dec. 24, 2021, by a meteoroid strike in the Amazonis Planitia region of Mars, is about 490 feet (150 meters) across, as seen in this annotated image taken by the High-Resolution Imaging Science Experiment (HiRISE camera) aboard NASA’s Mars Reconnaissance Orbiter. Credits: NASA/JPL-Caltech/University of Arizona
The meteoroid is estimated to have spanned 16 to 39 feet (5 to 12 meters) –
small enough that it would have burned up in Earth’s atmosphere, but not in
Mars’ thin atmosphere, which is just 1% as dense as our planet’s. The impact,
in a region called Amazonis Planitia, blasted a crater roughly 492 feet (150
meters) across and 70 feet (21 meters) deep. Some of the ejecta thrown by the
impact flew as far as 23 miles (37 kilometers) away.
With images and seismic data documenting the event, this is believed to be
one of the largest craters ever witnessed forming any place in the solar
system. Many larger craters exist on the Red Planet, but they are significantly
older and predate any Mars mission.
“It’s unprecedented to find a fresh impact of this size,” said Ingrid
Daubar of Brown University, who leads InSight’s Impact Science Working Group.
“It’s an exciting moment in geologic history, and we got to witness it.”
InSight has seen its power drastically decline in recent months due to dust
settling on its solar panels. The spacecraft now is expected to shut down
within the next six weeks, bringing the mission’s science to an end.
This meteoroid impact crater on Mars was discovered using the black-and-white Context Camera aboard NASA’s Mars Reconnaissance Orbiter. The Context Camera took these before-and-after images of the impact, which occurred on Dec. 24, 2021, in a region of Mars called Amazonis Planitia. Credits: NASA/JPL-Caltech/MSSS
InSight is studying the planet’s crust,
mantle, and core. Seismic waves are key to the mission and
have revealed the size, depth, and composition of Mars’ inner layers. Since
landing in November 2018, InSight has detected 1,318 marsquakes, including several caused by smaller meteoroid
impacts.
But the quake resulting from last December’s impact was the first observed to have surface waves – a kind of seismic wave that ripples along the top of a planet’s crust. The second of the two Science papers related to the big impact describes how scientists use these waves to study the structure of Mars’ crust.
This video includes a seismogram and sonification of the signals recorded by NASA’s InSight Mars lander, which detected a giant meteoroid strike on Dec. 24, 2021, the 1,094th Martian day, or sol, of the mission. Credits: NASA/JPL-Caltech/CNES/Imperial College London
Crater Hunters
In late 2021, InSight scientists reported to the rest of the team they had
detected a major marsquake on Dec. 24. The crater was first spotted on Feb. 11,
2022, by scientists working at Malin Space Science Systems (MSSS), which built
and operates two cameras aboard MRO. The Context Camera (CTX) provides black-and-white, medium-resolution images, while the Mars Color
Imager (MARCI) produces daily maps of the
entire planet, allowing scientists to track large-scale
weather changes like the recent regional
dust storm that further diminished InSight’s
solar power.
The impact’s blast zone was visible in MARCI data that allowed the team to
pin down a 24-hour period within which the impact occurred. These observations
correlated with the seismic epicenter, conclusively demonstrating that a
meteoroid impact caused the large Dec. 24 marsquake.
“The image of the impact was unlike any I had seen before, with the massive
crater, the exposed ice, and the dramatic blast zone preserved in the Martian
dust,” said Liliya Posiolova, who leads the Orbital Science and Operations
Group at MSSS. “I couldn’t help but imagine what it must have been like to
witness the impact, the atmospheric blast, and debris ejected miles downrange.”
Establishing the rate at which craters appear on Mars is critical for
refining the planet’s geologic timeline. On older surfaces, such as those of
Mars and our Moon, there are more craters than on Earth; on our planet, the
processes of erosion and plate tectonics erase older features from the surface.
New craters also expose materials below the surface. In this case, large
chunks of ice scattered by the impact were viewed by MRO’s High-Resolution
Imaging Science Experiment (HiRISE) color camera.
Subsurface ice will be a vital resource for astronauts, who could use it for a variety of needs, including drinking water,
agriculture, and rocket propellant. Buried ice has never been spotted this
close to the Martian equator, which, as the warmest part of Mars, is an
appealing location for astronauts.
This animation depicts a flyover of a meteoroid impact crater on Mars that’s surrounded by boulder-size chunks of ice. The animation was created using data from the High-Resolution Imaging Science Experiment (HiRISE) camera aboard NASA’s Mars Reconnaissance Orbiter. Credits: NASA/JPL-Caltech/University of Arizona
More About the Missions
JPL manages InSight and the Mars Reconnaissance Orbiter for NASA’s Science
Mission Directorate. InSight is part of NASA’s Discovery Program, managed by
the agency’s Marshall Space Flight Center in Huntsville, Alabama. Lockheed
Martin Space in Denver built the Mars Reconnaissance Orbiter, InSight
spacecraft (including its cruise stage and lander), and supports spacecraft
operations for both missions.
Malin Space Science Systems in San Diego built and operates the Context
Camera and MARCI camera. University of Arizona built and operates the HiRISE
camera.
A number of European partners, including France’s Centre National d’Études Spatiales (CNES) and the German Aerospace Center (DLR), are supporting the InSight mission. CNES provided the Seismic Experiment for Interior Structure (SEIS) instrument to NASA, with the principal investigator at IPGP (Institut de Physique du Globe de Paris). Significant contributions for SEIS came from IPGP; the Max Planck Institute for Solar System Research (MPS) in Germany; the Swiss Federal Institute of Technology (ETH Zurich) in Switzerland; Imperial College London and Oxford University in the United Kingdom; and JPL. DLR provided the Heat Flow and Physical Properties Package (HP3) instrument, with significant contributions from the Space Research Center (CBK) of the Polish Academy of Sciences and Astronika in Poland. Spain’s Centro de Astrobiología (CAB) supplied the temperature and wind sensors, and the Italian Space Agency (ASI) supplied a passive laser retroreflector.
Andrew Good, Jet Propulsion Laboratory, Pasadena, Calif.
Karen Fox / Erin Morton, NASA Headquarters, Washington
Source: NASA’s InSight Lander Detects Stunning Meteoroid Impact on Mars | NASA
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