ESA-гийн Ангараг гариг руу илгээх “Rosalind Franklin” хөлгийн багаж хэрэгсэлд хийсэн туршилтаар дэлхий дээрх солирын дээжид газрын тосны гаралтай бохирдол орсныг тогтоожээ.
Европын сансрын агентлагийн (ESA) “ExoMars” хөтөлбөрийн хүрээнд бүтээгдсэн “Rosalind Franklin” ровер нь 2030 онд Ангараг гаригийн Оксиа Планум бүсэд очиж, эртний бичил биетний амьдралын ул мөрийг хайхаар төлөвлөж байна. Энэхүү судалгааны гол багаж болох “Mars Organic Molecule Analyzer” (MOMA) нь дээж дэх органик нэгдлүүдийг ялгаж таних зориулалттай. Эрдэмтэд уг багажийн чадавхийг шалгах явцдаа 1969 онд Австралид унасан “Murchison” солирын дээжийг шинжилжээ.
Судалгааны баг амьд бие махбодоос үүсэлтэй “пристан” болон “фитан” хэмээх нүүрсустөрөгчдийг илрүүлэхэд чиглэсэн байна. Амьд организмууд нь ихэвчлэн тодорхой нэгэн “хирал” хэлбэрийн молекулыг үйлдвэрлэдэг бол химийн бус үйл явцаар үүссэн молекулууд хоёр хэлбэрээр тэнцүү хэмжээтэй байдаг. Туршилтын үр дүнд “Murchison” солир дээрх пристан болон фитан нь хоёр хэлбэрээрээ тэнцүү хэмжээтэй илэрсэн нь энэхүү бохирдол нь солир дэлхий дээр ирсний дараа эсвэл агаар мандлаар нэвтрэх үед чулуужсан түлшний шаталтын улмаас үүссэнийг баталж байна.
Энэхүү олдвор нь сансрын биетээс авсан дээж дэх органик молекулыг судлахад дэлхийн бохирдлыг хэрхэн ялгаж таних вэ гэдэг асуудалд чухал ач холбогдолтой юм. MOMA багажийн хирал ялгах чадвар нь Ангараг гариг дээрх амьдралын ул мөрийг хайх судалгаанд био-гарын үсгийг таньж илрүүлэхэд гол үүрэг гүйцэтгэх юм.
Дэлгэрэнгүйг эх сурвалжаас харах
↓Эх сурвалжийг нээх ↓
A routine test for a Mars-bound instrument has led to an unexpected discovery. While preparing the European Space Agency’s Rosalind Franklin rover for its mission, researchers found that a famous meteorite appears to have picked up petroleum-based contamination after reaching Earth, a finding that could influence how scientists study organic molecules in space rocks.
Mars has long been one of the most promising places to search for signs of ancient life. Scientists believe the planet was once warmer, wetter and surrounded by a much thicker atmosphere, creating conditions that may have supported simple microbial organisms. Yet proving that life ever existed there remains difficult, as organic molecules detected by NASA’s rovers can also form through non-biological processes.
The European Space Agency’s Rosalind Franklin rover, part of the ExoMars program, is designed to investigate that question. Scheduled to arrive on Mars in 2030, it will explore Oxia Planum, a clay-rich region thought to have hosted flowing water billions of years ago, using instruments built to analyze preserved organic compounds.
A Tool Designed To Separate Biology From Chemistry
At the center of the mission is the Mars Organic Molecule Analyzer (MOMA), an instrument developed under the leadership of the Max Planck Institute for Solar System Research with contributions from the University of Göttingen and the University of Côte d’Azur.
The team’s latest work, published in Earth and Planetary Science Letters, focused on two hydrocarbons: pristane and phytane. On Earth, both molecules originate from living organisms and are commonly found in petroleum, making them potential targets in the search for possible biosignatures.
MOMA analyzes gases released when rock samples are heated. The instrument combines miniature furnaces, a gas chromatograph, a mass spectrometer and an excitation laser. As compounds travel through specially coated capillary tubes, molecules with different mirror-image structures move at different speeds, allowing the instrument to separate and identify them.
“If life once existed on Mars, then molecules like pristane and phytane represent important molecular biosignatures that could have survived to this day,” lead author Guillaume Leseigneur said.
Chirality Could Explain It All
One part of the research focused on chirality, a property found in many organic molecules. Chiral molecules exist in two mirror-image forms, known as enantiomers, similar to the relationship between a person’s left and right hands.
The researchers explain that living organisms almost always produce one of these forms, while non-biological chemical processes usually create both in roughly equal amounts. This difference could help scientists determine whether an organic molecule was produced by life or by chemistry alone.
To test MOMA’s capabilities, the team used replicas of the instrument’s capillary tubes to separate the chiral forms of pristane and phytane for the first time. The achievement was especially challenging because both compounds are highly resistant to chemical reactions.
“Chiral separation of pristane and phytane requires high instrument sensitivity and measurement accuracy, both of which we show MOMA can achieve,” said co-author Fatma Yesil Sahan, a member of the MOMA team.
Co-author Uwe Meierhenrich added that chirality is “a valuable tool in the search for past extraterrestrial life.”
A Famous Meteorite Revealed an Unexpected Secret
To test the technique, the researchers analyzed the Murchison meteorite, which fell in Australia in 1969 and contains a wide range of organic molecules. Some compounds are part of the meteorite itself, while others were introduced after it arrived on Earth through contamination
The team expected pristane and phytane linked to biological contamination to show the same chiral imbalance seen in living organisms. Instead, the tests revealed that both mirror-image forms were present in equal amounts.
The researchers believe the contamination most likely came from aerosols produced by burning fossil fuels as the meteorite passed through Earth’s atmosphere or after it landed. Comparison tests on oil shales supported that explanation, providing valuable context for the search for similar organic molecules on Mars.
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