On February 18, 2021, the Perseverance rover touched down in Jezero Crater on Mars.
Since then, Perseverance has been exploring the region for evidence of past (and possibly present) life — just like its cousin, the Curiosity rover.
This includes obtaining samples that will be placed in the cache and retrieved by future ESA/NASA sample return missions.
These will be the first directly extracted Martian rock and soil samples to be analyzed in Earth labs and are expected to reveal some tantalizing information about the Red Planet’s history.
But it doesn’t look like we need to wait for the samples to return to the mission, as the Perseverance rover has already sent some surprising data back to Earth.
Perseverance’s ground-penetrating radar has detected an unusual dip in rock formations beneath the crater, according to a new study by a research team led by UCLA and the University of Oslo.
These odd parts could be caused by slow cooling lava flows or sediments from underground lakes.
The research team was led by Svein-Erik Hamran, professor of autonomous systems and sensor technology at the University of Oslo (UiO) and principal investigator of the Perseverance Mars Subsurface Experiment Radar Imager (RIMFAX).
He was joined by researchers from UiO, UCLA, the Planetary Science Institute (PSI), the Vestfonna Center for Geophysics, Astrobiology, the Norwegian Polar Institute, NASA’s Jet Propulsion Laboratory and several universities.A paper describing their findings recently appeared in the journal scientific progress.
Located in the Syrtis Major Planum between the northern lowlands and southern highlands, Jezero crater is about 45 kilometers (28 miles) in diameter and is believed to have once been a lake.
The area was specifically chosen as the landing site for Perseverance, and the company has been exploring the massive deposits of rock and clay minerals on its western edge, where water once flowed into the crater.
Like Curiosity, the aim is to learn more about the period when Mars had flowing water on its surface so scientists can better understand how (and when) it transformed into the cold, arid planet it is today.
As they noted in their study, the team consulted the first data obtained by the Radar Imager for the Mars Subsurface Experiment (RIMFAX), which conducted the first rover-mounted ground-penetrating radar survey of the Martian subsurface.
The survey was conducted during the rover’s initial 3 km (~1.85 mi) hike through Jezero Crater and provided continuous data on the electromagnetic properties of bedrock structures 15 m (~49 ft) below the crater . surface.
The resulting radar images show layered sequences that slope downward at angles of up to 15 degrees.
David Page, UCLA professor of Earth, planetary and space sciences and one of the principal investigators at RIMFAX, explained in a recent ULCA newsroom release:
“We were surprised to find that the rocks were stacked at an inclined angle. We were expecting to see horizontal rocks at the bottom of the crater. The fact that they were inclined like this requires a more complex geological history.
They may have formed when lava rose to the surface, or, alternatively, they may represent older delta deposits buried at the bottom of the crater. “
RIMFAX maps Mars’ subsurface geology by emitting a series of radar waves to the surface, which are reflected by rock formations and other features below the surface. This allows scientists to determine the shape, density, thickness, angle and composition of subsurface objects based on how radar waves return to the instrument.
After analyzing the data, the team noted that layered rocks were common throughout the area surveyed by Perseverance. Even more puzzling, they also found that the sloping regions have highly reflective rock formations sloping in multiple directions.
The most likely explanation for the angled layers they witnessed points to an igneous (melting) origin, where the movement of subterranean magma deposited rock layers over time, which then cooled and solidified.
However, it is also possible that these layers were sedimentary, a phenomenon common in Earth’s aquatic environments.
In this case, the features are due to water depositing material over time, which hardens and becomes delaminated. As Page said, this reminds me of another familiar Earth feature:
“RIMFAX gave us a view of the Martian formations, similar to the highway road cuts you see on Earth, sometimes high rock formations on hillsides as you drive past.
Before Perseverance landed, there were many assumptions about the exact nature and origin of the crater’s ground material. We’ve been able to narrow down the possibilities now, but the data we’ve obtained so far suggest that the history of the crater floor may be more complex than we expected. “
The data collected by RIMFAX will be of great value when the samples collected by Perseverance are returned to Earth for analysis. Knowing what lies beneath Jezero Crater and how it formed will provide the necessary context to characterize the sample.
This will provide a clearer picture of how and when there is flowing water on the surface of Mars, for how long, and whether this is intermittent. It will also show how and when Mars transitioned to the extremely cold and dry conditions we see there today.
But most importantly, the data could reveal whether Mars could support life on its surface, which will finally answer the question humans have been asking for centuries!
This article was originally published by Universe Today. Read the original text.