Space

Biomarker for life found in space for the first time – and that's bad news

Biomarker for life found in sp...
Molecules once thought to be biomarkers for life have been detected around a young star in the Rho Opiuchi star-forming region of space
Molecules once thought to be biomarkers for life have been detected around a young star in the Rho Opiuchi star-forming region of space
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A diagram showing how star systems form, and what role comets play
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A diagram showing how star systems form, and what role comets play
Molecules once thought to be biomarkers for life have been detected around a young star in the Rho Opiuchi star-forming region of space
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Molecules once thought to be biomarkers for life have been detected around a young star in the Rho Opiuchi star-forming region of space

The European Space Agency (ESA) has some good news and bad news for extraterrestrial enthusiasts. The good news is that a molecule thought to be a biomarker for life has been found for the first time in abundance in a comet and around a young star. The bad news is that the find indicates that the molecule isn't the clear indicator of life that it was once believed to be.

Since we can't exactly spot microscopic lifeforms from afar, astronomers have adopted other ways to measure a particular planet's likelihood of housing alien life. Traces of certain compounds left by organic processes, often called biomarkers, can be sifted out of soil or water samples by rovers, or detected in the atmosphere by telescopes and orbiters.

Methyl chloride is fairly common here on Earth, belonging to a class of molecules known as organohalogens. These organic compounds are made up of carbon bonded to at least one halogen – fluorine, chlorine, bromine or iodine – and are produced mostly through biological processes. In theory, that means that any celestial body where we detect an abundance of these is a good place to look for life.

Recently, the Atacama Large Millimeter/submillimeter Array (ALMA) telescope in Chile found methyl chloride around a young binary star known as IRAS 16293-2422, about 400 light-years away in a star-forming region of space called Rho Ophiuchi. This marks the first time any organohalogen has been spotted in space, but rather than give hope that life exists in that system, the discovery instead throws doubt on methyl chloride's reliability as a biomarker.

The presence of these organic compounds around such a young star suggests they may arise during the planet-forming phase of a system. To get a better understanding of how the molecules may form, the researchers turned their attention to a comet, which acts as time capsules from the birth of a star, preserving the chemical composition of the cloud of material stars arise from.

A diagram showing how star systems form, and what role comets play
A diagram showing how star systems form, and what role comets play

In this case, the team zeroed in on Comet 67P/Churyumov–Gerasimenko, which was visited by the ESA's Rosetta mission between 2014 and 2016. By sifting through the data collected by the spacecraft, the team found an abundance of methyl chloride in the comet, lending further weight to the idea that the compound arises during the planet-forming phase. In particular, the signals were strongest in measurements made in May 2015, when the comet was approaching the Sun and was giving off a lot of hydrogen chloride.

"We found it but it is very elusive, one of the 'chameleons' of our molecule zoo, only present during short times when we observed a lot of chlorine," says Kathrin Altwegg, principal investigator of the project.

The find may be disappointing for those hoping to find life in the cosmos, but it doesn't mean the search is off: rather, it's just a little more complicated than previously thought.

Source: ESA

8 comments
RobertEhresman
There is something ironic about this.... Methyl chloride! If we find that in space it will indicate life! Ah dang, we found methyl chloride in space, I guess it cant be used to indicate life...
jose_raymond
Let's continue searching for real life (or molecules clearly related to some kind of virus or bacteria) in Mars where conditions has been very much like Earth's 4 billion years ago when life started here.
WolfeSA
There's a pattern to both the search for a complete fossil record and E.T.; both have goalposts that seem to move around an awful lot. :-) The only certainty we have is that we're here... Oh wait, I forgot about spirituality. Mysteries everywhere!!!
JimBobway
I guess we will have to wait until either they come here or we go there... lol
dib
Not much longer until the myth of "fossil fuels" being dead dinos and is running out gets more main stream.
Douglas Bennett Rogers
When we have even one data point for exobiology, everything will change.
JimFox
Challenge- can anyone propose a REAL, SUBSTANTIAL benefit to the 'search for life'? Vast amounts of cash wasted- for what? If even primitive life is found- so what? Will we contact it & talk to microbes? As for SETI, that's more ridiculous yet; even at radio wave or light speed there's no point- we will never find anything useful. No, I am not impressed by "they are already here among us" arguments.
Pete0097
Why couldn't it be from the end of life on a planet as well? It is in a star forming area that was, in all likelihood, an area where stars and their systems died in the past.