A "biomarker" molecule presumed to indicate the presence of industrial or biological activity has been found to be naturally occurring in interstellar clouds:
A molecule once thought to be a useful marker for life as we know it has been discovered around a young star and at a comet for the first time, suggesting these ingredients are inherited during the planet-forming phase.
The discovery of methyl chloride was made by the ground-based Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, and by ESA's Rosetta spacecraft following Comet 67P/Churyumov–Gerasimenko. It is the simplest member of a class of molecules known as organohalogens, which contain halogens, such as chlorine or fluorine, bonded with carbon.
Methyl chloride is well known on Earth as being used in industry. It is also produced naturally by biological and geological activity: it is the most abundant organohalogen in Earth's atmosphere, with up to three megatonnes produced a year, primarily from biological processes.
As such, it had been identified as a possible 'biomarker' in the search for life at exoplanets. This has been called into question, however, now it is seen in environments not derived from living organisms, and instead as a raw ingredient from which planets could eventually form.
This is also the first time an organohalogen has been detected in space, indicating that halogen- and carbon-centred chemistries are more intertwined than previously thought.
Also at the Harvard-Smithsonian Center for Astrophysics.
Protostellar and cometary detections of organohalogens (open, DOI: 10.1038/s41550-017-0237-7) (DX)
Related Stories
The presence of large quantities of oxygen ions may be able to distinguish habitable exoplanets with life from barren exoplanets in the habitable zone (resembling Venus or Mars):
Like Earth, Venus and Mars are small rocky planets; they have permanent atmospheres like Earth, and their atmospheres are exposed to the same solar radiation as Earth's. Data from the Pioneer Venus Orbiter and the Viking descent probe on Mars show that they have very similar ionospheres to each other—which don't contain a lot of atomic O+ ions. Know what else Venus and Mars are missing? Photosynthesis.
[Astronomy PhD candidate Paul] Dalba's contention is that photosynthesis on a planet's surface, which generates a surfeit of molecular oxygen, is the only thing that can account for these atomic O+ ions in a planet's ionosphere. The mere existence of life throws a planet's atmosphere out of chemical balance. O+ would be a neat biomarker because there isn't a numerical cutoff required—just the dominance of O+ among the ionic species in the upper atmosphere would indicate "thriving global biological activity" on the planet below.
Dalba claims that Venus and Mars act as negative controls, demonstrating that planets like Earth but lacking life don't have this O+ layer. Some may think that continuous volcanic activity on the surface could also generate enough oxygen, but Dalba doesn't. Chemistry involving water and UV light [open, DOI: 10.1038/srep13977] [DX] can also release oxygen. But the amount of water on Earth is insufficient to account for the requisite oxygen content, so he thinks that the presence of water on other planets wouldn't make enough oxygen there either.
Atomic oxygen ions as ionospheric biomarkers on exoplanets (DOI: 10.1038/s41550-017-0375-y) (DX)
Related: Nitrogen in Ancient Rocks a Sign of Early Life
Oxygen Ions From Earth Escape to the Moon
Researchers Suffocate Hopes of Life Support in Red Dwarf "Habitable Zones"
Seven Earth-Sized Exoplanets, Including Three Potentially Habitable, Identified Around TRAPPIST-1
Cosmic Methyl Chloride Detection Complicates the Search for Life on Exoplanets
Mars Colonists Could Produce Oxygen by Making a Plasma Out of Atmospheric Carbon Dioxide
Analysis of Microfossils Finds that Microbial Life Existed at Least 3.5 Billion Years Ago
To Detect Life on Other Planets, Look for Methane, Carbon Dioxide, and an Absence of Carbon Monoxide
(Score: 1, Funny) by rylyeh on Tuesday October 03 2017, @11:37PM (1 child)
"a vast crenulate shell wherein rode the grey and awful form of primal Nodens, Lord of the Great Abyss."
(Score: 0) by Anonymous Coward on Wednesday October 04 2017, @12:42AM
Hey..hey...let's keep politics out out this discussion. Maybe we should talk about sex instead.
So...FUCK TRUMP!!
(Score: 3, Interesting) by Fluffeh on Tuesday October 03 2017, @11:49PM (1 child)
I actually love it when a perfectly accepted statement is proven wrong. For example, for so long there was consensus among all the chemists in the world that Fluorine gas was never going to be found in nature. I mean it reacts with ANYTHING this stuff. Never going to be found. Can't find it. And then... one day.... there it was [chemistryworld.com]... found in nature.
It just seems that we look at something, think up all the possibilities, convince ourselves, then somehow, the universe finds a way to prove us wrong. Must be awe-inspiring to be the folks that find these things.
(Score: 4, Insightful) by PinkyGigglebrain on Wednesday October 04 2017, @01:09AM
When I read things like the original article and the one you linked to (thank you) or hear/read about how "such and such, once thought to be impossible etc., etc." I always remember the two quotes that sum it up beautifully.
Shakespear's "Hamlet"
and Sir Arthur Eddington's
Humanity still has so far to go before we even begin to fully understand how it all works. But at least some people are trying :)
"Beware those who would deny you Knowledge, For in their hearts they dream themselves your Master."
(Score: 3, Insightful) by lx on Wednesday October 04 2017, @06:06AM
There is life in interstellar clouds.
It's a long shot, but we don't know what extraterrestrial life is like.