A sample of the Murchison meteorite, plus a test tube containing powdered meteorite material (DoE)
A meteorite that hit the town of Murchison, Australia, hasn’t quit giving up its secrets.
The Murchison meteorite is one of the most studied space rocks because many pieces were recovered after it was seen breaking up as it fell through the atmosphere in 1969. Approximately 100 kg of the carbonaceous chondrite was recovered.
Carbonaceous chondrites are extremely important to scientists as they were formed from material that existed in the solar system’s planet-forming disk of gas and dust. They are, quite literally, time capsules holding onto a 4-billion-year-old record of the birth of our solar system.
In this case, the Murchison meteorite has given us another clue to the abundance of organic chemicals that existed before the Earth formed. In fact, this particular meteorite may have originated from material older than our sun.
“We are really excited. When I first studied it and saw the complexity I was so amazed,” said Dr Phillipe Schmitt-Kopplin, of the Institute for Ecological Chemistry in Neuherberg, Germany.
“Meteorites are like some kind of fossil. When you try to understand them you are looking back in time.”
This new research used high-resolution spectroscopic tools to identify the various compounds inside. Although this meteorite has provided scientists with vast amounts of information about specific carbon-based organics before, this was the first non-targeted study. In other words, the researchers weren’t tracking down just one type of chemical; they did a broad analysis for all of the chemicals it might contain.
And what they found came as a shock. It appears that the primordial solar system probably had a higher chemical diversity than present-day Earth.
In this study, 14,000 specific compounds, including 70 amino acids, were identified. But this number appears to be the tip of the iceberg; the meteorite probably contains millions of different organic compounds. More detailed analysis will now be carried out.
But why is this important? Understanding the diversity of organic chemicals that were floating around a primordial solar system will help us understand how life may have appeared on Earth. This particular chunk of carbonaceous chondrite drifted through the gas and dust of the early solar system, collecting all the basic organic chemistry from around that time. Does that mean diverse organic chemistry is the “norm” for proto-planetary star systems?
These organic compounds are known to exist on comets, asteroids and other planetary bodies, so what makes Earth the hothouse of life when everywhere else seems to be lifeless?
If organic chemistry is ubiquitous, perhaps planning to “seed” young star systems with Earth-based life isn’t such a good idea. The conditions for life may not be that rare after all.