the Perseverance in the rover She landed on the planet only 10 months ago, but she has already made amazing discoveries.
The rover’s recent discovery indicates that the rocks it’s been traversing since the descent were formed from lava flows — something that “was completely unexpected,” according to expedition scientists. Previously, the layered rocks depicted by perseverance were thought to be sedimentary.
The rock samples tested so far have revealed that they have interacted with water multiple times, and some of them contain organic molecules.
These findings could help scientists create an accurate timeline of events that occurred at Jezero Crater, the site of an ancient lake, and have broader implications for understanding. Mars.
The discovery was announced Wednesday (15) during the fall meeting of the American Geophysical Union in New Orleans.
For years, scientists have wondered whether the rocks in this crater were sedimentary, made up of layers of material deposited by an ancient river, or igneous, which forms when lava flows to cool.
“I’m starting to despair that we’ll never find the answer,” said Ken Farley, a perseverance project scientist at the Caltech in Pasadena, Calif., in a statement.
Everything changed when Perseverance began using a drill at the end of her robotic arm to scrape the surfaces of rocks.
“The crystals inside the rock were the right shot,” Farley said.
Perseverance is equipped with a suite of advanced tools that can image and analyze these fractured rocks, revealing their composition and mineral content. One such tool is PIXL, or the Planetary X-Ray Lith Chemistry Instrument.
In November, the Perseverance used their tools to study a rock the team dubbed “Brak”. The analysis revealed large olive crystals surrounded by pyroxene crystals, both of which point to the fact that the rocks came from lava flows.
“A good student of geology will tell you that this texture indicates rock formation when crystals slowly grew and settled in cold magma—for example, a dense lava flow, a lava lake, or a magma chamber,” Farley said.
“The rock was then altered several times by water, becoming a treasure that will allow future scientists to chronicle events on Jezero, better understand the period when water was most common on its surface, and reveal the beginning of the planet’s history. The return of the Martian specimen will have great options to choose from. .”
The team now wants to know whether the olivine rock was formed by a lake of cooling lava or originated from an underground lava chamber that was later exposed to erosion.
“This was completely unexpected and we are working to understand what it means,” Farley said. “But I will guess that this is probably not the bottom of the original crater. From the diameter of this crater, we would expect the original bottom to be much deeper than we are now.”
It’s possible, he said, that lava flowed into the crater, but that the bottom of the original crater is below the rock they’re now passing over.
Resampling
So far, Perseverance has collected four rock samples with plans to collect another 37, and these samples will be returned to Earth on future missions, which will allow them to be studied in great detail and in a variety of ways. Samples from Jezero crater and river delta can reveal whether life exists on Mars.
Once back on Earth, the igneous rocks can be dated to a very high accuracy, so these fresh samples could help the team establish more accurate dates for features and events on Mars.
These rocks react with water over time to form new minerals.
The minerals in the samples can reveal what the climate, the environment, and even the composition of the water were like billions of years ago on the Red Planet.
“This will tell us whether or not the water in there could have been habitable in the past,” said Kelsey Moore, a geologist and postdoctoral fellow in Planetary Science Research at Caltech.
The rover has also detected organic molecules in rock samples, using its SHERLOC instrument, or the Raman & Luminescence Habitable Environment Scanner for Organics and Chemicals.
The presence of organic molecules does not necessarily imply signs of past life or biosignatures. Organic matter can be created biologically or abiotically – a physical process that does not involve living organisms.
The Curiosity rover, which landed on Mars in 2012, detected organic materials at its landing site in Gale crater. Now that persistence has discovered it, Luther Beagle, principal investigator for SHERLOC at NASA’s Jet Propulsion Laboratory in Pasadena, said in a statement, “it helps us understand the environment in which organic matter formed.”
While more research is needed to determine how these organic molecules are created, their presence gives the science team hope. This is because it means that signs of past or present life could also be preserved on Mars, if life was present there.
“When these samples are returned to Earth, they will be a source of scientific investigation and discovery for many years to come,” Beagle said.
Perseverance also used the ground-penetrating radar instrument on board, the first to be tested on Mars.
Briony Horgan, an assistant professor of planetary sciences at Purdue University and a rover mission scientist, said the Mars Surface Imaging Experimental Radar, or RMFAX, was used “to spy on the surface and identify the structure of a rock under the wheels.”
The experiment was used while driving the rover through a ridge. Radar data revealed multiple downward-sloping rock formations that continue below the surface from the same summit line.
Tools like RIMFAX could help scientists create a better geological map of Mars to understand its history.
Investigation of an ancient river
Perseverance had a historic year in 2021 and will move to an even more interesting area next year: the former river delta.
This fan-shaped structure has intrigued scientists for years, and Farley said the rover will reach the Delta in about six to eight months.
The rocks in the delta are likely sedimentary, trapping and preserving precious layers of silt from the river that once drained into the crater lake. The samples could reveal whether organic molecules associated with signs of life, or even microfossils, could be hiding within the delta’s debris.
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