Building Blocks of Life Can Be Forged by 'Dark Chemistry' in Interstellar Space
- November, 17, 2020 - 16:57
- Science news
TEHRAN (Tasnim) – Researchers have discovered that at least one of the earliest precursors for life can form in interstellar space without the need for sunlight, in a process known as ‘dark chemistry’.
The prebiotic molecule in question is the amino acid glycine, one of the simplest and most fundamental building blocks of life.
It was previously thought to require irradiation from a star to form, but a team of scientists investigating the origins of life has now found that it can form in the unforgiving wasteland of interstellar space, away from the light of stars and the gravitational pull of planets.
Glycine has previously been found on Comet 67P/Churyumov-Gerasimenko, so the boffins conducted laboratory experiments and modelling to see if they could recreate the prebiotic molecule using “dark chemistry,” which occurs without the presence of energetic irradiation.
Through a series of independent experiments, the team found that methylamine, itself a precursor to glycine, could form without the need for a star’s energy in the harshness of interstellar space.
Astronomers have found methylamine in the interstellar medium and detected it on Comet 67P/C-G so their ‘dark chemistry hypothesis’ was off to a good start.
Next, they introduced methylamine-enriched ice into an ultra-high vacuum system called SURFRESIDE2, which is custom-designed to reproduce the conditions found in interstellar space. The temperature of the system was dropped to 13 Kelvin (-260 degrees Celsius, or -436 degrees Fahrenheit) to allow ice to form in the chamber.
To their amazement, glycine did form. They then produced astrochemical models to validate what they had found, by taking their findings from a day's worth of experiments and extrapolating them out to the timeframe of millions of years. They found that glycine could form in small but significant amounts given enough time.
Lead researcher Sergio Ioppolo, of Queen Mary University London, explained: “In the laboratory we were able to simulate the conditions in dark interstellar clouds where cold dust particles are covered by thin layers of ice and subsequently processed by impacting atoms causing precursor species to fragment and reactive intermediates to recombine.”
“Once formed, glycine can also become a precursor to other complex organic molecules,” the astrochemist added.
The research is yet another step back towards the dawn of time and the origins of every species we have yet discovered in the universe.
The team extrapolates that, in principle at least, other amino acids such as alanine and serine could also form in dark clouds in interstellar space. This “enriched organic molecular inventory” is then picked up by passing comets and meteorites before eventually being delivered to young planets, like the Earth.