Meteorite, Maybe Older Than the Sun, Shows Chemistry of Ancient Solar System
Four decades later, the Murchison meteorite is still full of surprises. When this extraterrestrial hunk fell to Earth near its namesake town in Australia in 1969, people managed to salvage more than 200 pounds of it. And now a new analysis of the meteorite, published this week in the Proceedings of the National Academy of Sciences, shows that it could hold millions of carbon-containing compounds. Researchers say the findings provide insight into the complex chemistry present when the chunk of space-rock formed, back when our solar system was young.
Back in 1969, researchers found amino acids and many other molecules in the carbon-rich rock. Many researchers have analyzed the chondritic meteorite for amino acids and other possible precursors to life, because some theories hold that life on Earth began with the delivery of prebiotic organic compounds from space via asteroids or comets [Scientific American]. But scanning techniques have advanced since then, so the new team used tools like ultra-high-resolution mass spectrometry to take a fresh look at the meteorite.
In the tiny sample they crushed to study, the team turned up at least 14,000 unique organic (carbon-containing) compounds. They say that is actually conservative guess; the somewhat limited scope of their tool could have missed some, and the true number could be as high as 50,000. And because each collection of atoms can be arranged in numerous ways, the authors estimate that there may be millions of distinct organic compounds in the meteorite [Scientific American].
Not only is Murchison rich in organic compounds, it’s old. Scientists believe the Murchison meteorite could have originated before the Sun was formed, 4.65 billion years ago. The researchers say it probably passed through primordial clouds in the early Solar System, picking up organic chemicals [BBC News]. As a result, the researchers say the meteorite could have something to say about the origin of life and our solar system as it continues to let go of its secrets. It was only two years ago, after all, that scientists confirmed that the presence of subunits of DNA and RNA on Murchison were genuine, and not the result of soil contamination.
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