Space

Missing ingredient for life finally found on a comet

Missing ingredient for life fi...
The Rosetta spacecraft was the first mission to enter orbit around a comet, its subject: 67P/Churyumov–Gerasimenko
The Rosetta spacecraft was the first mission to enter orbit around a comet, its subject: 67P/Churyumov–Gerasimenko
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The Rosetta spacecraft was the first mission to enter orbit around a comet, its subject: 67P/Churyumov–Gerasimenko
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The Rosetta spacecraft was the first mission to enter orbit around a comet, its subject: 67P/Churyumov–Gerasimenko

Researchers have detected phosphorus on a comet – thereby completing the grocery list of elements that are essential for life. The discovery was made in data from comet 67P/Churyumov-Gerasimenko by the Rosetta probe a few years ago, strengthening the idea that life’s ingredients were delivered to Earth by comets.

Six chemical elements make up almost all biological molecules on Earth: carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur (CHNOPS). How our home planet managed to become so bountiful in all of them has long been a mystery, but one of the leading hypotheses is that they were brought here long ago by comets, asteroids, and impacts with proto-planets.

The first four are simple enough – they’re the main ingredients of carbonaceous asteroids, the most common type of space rock in our neighborhood. Sulfur turned up during a chemical analysis of comet 67P’s gassy coma, which according to ESA would give it a pungent rotten egg smell.

That left just phosphorus. Previous studies have suggested that this element, crucial for making the compound that our cells use to store and transfer energy, is relatively rare across the universe. And without it, life may not emerge very easily.

Now, the stuff has finally been found on a comet. A new study, led by the University of Turku in Finland, made the discovery by analyzing data from the Cometary Secondary Ion Mass Analyzer (COSIMA) instrument onboard Rosetta. The instrument collected dust particles from the coma of comet 67P, photographed them, and measured them using a mass spectrometer.

In those solid particles, the team detected minerals containing phosphorus ions. This first-time discovery marks the last required CHNOPS element to be found in a comet, lending weight to the hypothesis that these icy objects were responsible for delivering the ingredients of life to Earth, billions of years ago. They've also been proposed to be the source of other vital compounds, such as amino acids and "ocean-like" water.

The team also detected fluorine in the dust, in the form of CF+ secondary ions. Exactly what role it plays in the comet’s environment remains unknown, but the researchers say it’s a curious find nonetheless.

The research was published in the journal Monthly Notices of the Royal Astronomical Society.

Source: University of Turku

6 comments
6 comments
buzzclick
After billions of years of constant and slow evolution in the Universe, some planets got more of some elements than others, as we can witness in our own galaxy. Extra terrestrials discovered that our Earth had an ideal mix of conditions and elements that could harbor intelligent life. So they decided to plant a seed of a homo sapien strain and see what would come of it. And here we are. Someone's biology experiment. Over the course of millennia, we've evolved in a number of directions, closely watched by our ET guardians who are curious to see how and if we will screw things up, quite predictably.
Wavmakr
So where is the missing link?
lee54
Why is it that these elements had to have been brought to earth by comets? Is it not possible that they were here all along, and were part of interstellar gas and dust that eventually coalesced to form the earth? What is so special about comets that cause them to have elements that were not present when the larger solar system formed? This theory of seeding by comets has always puzzled me.
neutrino23
It would be interesting if you could contrast why the appearance of these elements in comets differs in importance from their appearance in meteorites. Troilite (FeS) and Schreibersite ( (Ni,Fe)3P ) are rather common in chondritic meteorites. Troilite is especially common. I see it all of the time when analyzing chondritic meteorites.

This report discusses the importance of meteorites as a source of P.

https://www.innovations-report.com/earth-sciences/report-32724/

I have no complaints about the work cited above, it would be interesting to learn more background on this topic.
Signguy
Entropy automatically makes this invalid.
Kpar
OK, buzzclick, where did your "extra terrestrials" come from?

Although I do agree that we are screwing things up, and quite spectacularly...