On the floor of a crater shallow in Marsthe rover perseverance of the POT stumbled upon what scientists hope is fertile land. Martian rocks excavated by the rover they show signs of a watery past and are loaded with the kind of organic molecules that are the basis of life as we know it.
Scientists collaborating on the mission also say the rock sampleswhich the rover has stored in tubes for a future return to Earth. Landhave the correct chemical recipe to preserve evidence of ancient martian lifeif it ever existed.
The new Perseverance research is detailed in three large studies published Wednesday, one in the magazine Science and two in the magazine Science Advances. The magazine reports are highly technical and devoid of exaggeration, daring to be boring as dirt, but translated into a more exciting story by the scientists involved.
“Is incredible. In almost all rocks we find organic compounds“, said abigail allwoodgeologist of the Jet Propulsion Laboratory of NASA in Pasadena, which operates the rover and the mission Mars Sample Return.
One of the studies concluded that the crater rocks experienced three different events in which they were exposed to water.
“Crucially, the conditions in the rock during each time water migrated through it could have supported small communities of microorganisms,” the lead author said in an email. michael ticegeologist of the Texas A&M University. In a later interview, he added: “We won’t know until we get the samples back to Earth.”
Perseverance landed on the Jezero crater on February 18, 2021 and has been wandering ever since, storing rock samples along the way for later scrutiny on Earth. This is an ambitious, multi-phase mission that will require NASA to send another rover to the surface of Mars with the ability to put samples into orbit. A spacecraft would then carry those samples back to Earth for laboratory research. The precise timetable has yet to be determined, but NASA hopes to have the samples home by the early 2030s.
This study of Mars is part of the growing and young field of astrobiologywhich includes the search for potentially habitable worlds and the first example of extraterrestrial life. Despite the efforts of generations of scientists and the claims of hobbyists ufosthe discovery of life beyond Earth remains an aspiration.
even find organic compounds (life-friendly molecules with combinations of carbon, hydrogen Y oxygen) is a long way from discovering life or even proving its presence in the past. Such molecules may be of biological or non-biological origin.
Still, Mars is front and center in NASA’s search because it has so many favorable features. Mars was probably much more like Earth around 3 billion years ago, with warmer and wetter conditions. Life may have once existed on Earth and Mars simultaneously, and it is possible that it originated on Mars and spread to Earth via meteors. And though the surface is now a arid wastelandthe planet could have liquid water in significant quantities below the surface and possibly life”cryptic”.
Although the Perseverance rover does not have instruments to chemically detect living organisms if they exist today, its instruments give scientists the ability to study the Martian surface at a level of detail never before possible.
One of the new papers taking a closer look at the chemistry of Mars has given geologists a surprise. They had assumed they were going to dig up a bunch of sedimentary rocks. Instead, the rocks are volcanic.
The Jezero crater it was formed in an impact event, a rock that crashed into Mars, at least 3.5 billion years ago. The shallow crater clearly had water in it a long time ago. This could be determined from orbital images showing the remains of a delta where a river emptied into the lake. Planetary geologists had assumed that the crater floor was covered in sedimentary rock, made up of dirt and debris that slowly accumulated on the lake floor.
If such a sedimentary rock was ever there, it is now gone. It may have eroded, Tice said. The lack of sedimentary rock could mean the lake didn’t last long, which would be disappointing to astrobiologists. Life as we know it needs water, and it takes time for more complex life forms to evolve. If the lake had not lingered, life might have struggled to take root.
However, the volcanic rocks They are not a disappointment because they retain a lot of information about the Martian past, including the presence of organic molecules, the scientists said. The presence of organic material on Mars had been confirmed in previous missions, but its precise nature and chemistry cannot be discerned through this type of long-distance investigation and will require laboratory scrutiny on Earth, according to Bethany Ehlmanplanetary scientist at Caltech and co-author of two of the new articles.
“Are they just organics that got into the system, perhaps from meteoritic material that was just part of the water? That would be the least exciting. Or are they small niches of microbial life that live in the cavities of these rocks? That would be the most exciting,” Ehlmann said.
He added that the rover “is collecting an impressive set of samples to reveal the environmental history of Mars in all its forms: the volcanic history, the water history, the relationship of organic matter to those water-rich environments.”
This is all an attempt to solve the fundamental mystery of Mars: What went wrong? How, when and why did this planet that was apparently conducive to life become such a harsh place? maybe the Red planet not a dead planet (the coroner’s report is incomplete), but it certainly looks like one.
The scientists point to something that Mars lacks today: a global magnetic field like Earth’s. Such a field protects our atmosphere from the corrosive effects of the solar wind: high-energy particles that constantly stream in from the sun and can knock out lighter molecules. Mars also lacks plate tectonics, the geologic process that on Earth recycles the crust and continues to spew water and nutrient-rich lava through active volcanoes.
Somewhere along the way the magnetic field of mars it died and then became a different kind of planet. It lost almost all its atmosphere. It became a frigid desert world. How quickly it happened is unknown, but that is something that could be revealed by the volcanic rocks in the crater.
The magma contains some amount of iron, which is sensitive to a planet’s magnetism. As the lava cools, it crystallizes into igneous rock, freezing electrons inside iron-bearing minerals in patterns that could reveal the features of a magnetic field, such as its orientation.
Benjamin Weiss, planetary scientist MIT and co-author of two of the papers, said in an email: “Overall, we’re actually very lucky that there are igneous rocks in the crater and that we landed right on them.” , since they are ideal for determining ages and studying the past history of the magnetic field of Mars”.
Once the mission is able to send its precious collection of rocks back to Earth, scientists will finally be able to know if life ever found a foothold on Mars, raising new questions about whether, despite the planet’s dramatic transformation , life somehow managed to persevere. .
(c. 2022 – The Washington Post)