Cold chemistry: Icy dust specks could provide interstellar staging ground for complex organic chemical reactions

Oct 31, 2011

The creation of the Universe was a messy business, and billions of years after the Big Bang, material still litters the dark space between stars. In these cold interstellar regions, gas and dust specks swirl together, sometimes coalescing to form new stars, sometimes expanding as dying stars spew forth new material into the void. Much of the chemistry that happens in interstellar clouds remains a mystery, but recent work by astrochemists from Heriot-Watt University in Edinburgh sheds new light on this dark part of the Universe, demonstrating the key role that icy dust specks can play in facilitating the formation of a type of organic molecule that could be a precursor to the building blocks of life. The researchers will present their work at the AVS Symposium, held Oct. 30 – Nov. 4, in Nashville, Tenn.

By some estimates molecules make up less than 1 percent of the matter of the Universe, but they can still significantly influence the evolution of stars and planetary systems. Scientists suspect, based on infrared observations, that many of the dust specks within are covered in a frosty coating of ice. The ice acts as a coolant during star formation, leading to smaller, longer-lived stars such as our own Sun.

"Small stars give evolution on planets time to work," says Martin McCoustra, an astrochemist who studies interstellar ice grains. "Basically we wouldn't be here if the Universe was clean and dust free." In addition to slowing down star evolution, icy dust specks may also influence interstellar organic , speeding up chemical reactions or shielding molecules from the full energy of incoming cosmic rays.

It is this chemical catalyst behavior of interstellar dust that McCoustra and his colleagues are currently investigating. Using silica and water ice surfaces, the scientists created models of both bare and icy dust grains in the laboratory, and then bombarded the grains with low-energy electrons to mimic an influx of cosmic rays. The researchers were specifically looking for the effect that the rays would have on acetonitrile (CH3CN), a simple organic compound that has been observed in the interstellar medium. They found that for films of bulk CH3CN, the incoming electrons rapidly dislodged the molecules, but for CH3CN molecules isolated on icy surfaces, a chemical reaction took place. CH3CN is believed to be a to amino acids, McCoustra says, and the product of the reaction, which the scientists are still working to precisely identify, is probably part of an intermediate step in the process that makes large organic molecules. "The key point is that the water is crucial for this chemistry," McCoustra notes, since the chemical reaction did not take place in bulk CH3CN.

The Scottish research team, part of a large European network studying solid state and surface astrochemistry (LASSIE), is now working with computational chemists to further investigate, from an energy point of view, how water might promote chemistry on icy grains. "Astronomers and astrochemists are working to try and understand the origin of chemical complexity," says McCoustra. "If that chemistry is the same wherever we look in our galaxy, and if we can reproduce it in the laboratory, then that chemistry can seed our galaxy and others with the chemical potential for life."

Explore further: Computers beat brainpower when it comes to counting stars

More information: The AVS 58th International Symposium & Exhibition will be held Oct. 30 – Nov. 4 at the Nashville Convention Center.

Presentation SS1-MoM1, "Surface Science of Acetonitrile on Model Interstellar Ices and Grains," is at 8:20 a.m. on Monday, Oct. 31.

Provided by American Institute of Physics

4.5 /5 (2 votes)

Related Stories

Dusty experiments are solving interstellar water mystery

Apr 14, 2010

(PhysOrg.com) -- Dust may be a nuisance around the house but it plays a vital role in the formation of the key ingredient for life on Earth - water - according to researchers at Heriot-Watt University. The ...

Water around massive young stars

Sep 16, 2010

Water is critical to human life, but also plays an important role in the life of stars and their planetary systems. As a gas, water helps to cool collapsing clouds of interstellar material so that they can ...

The making of dust

Jul 06, 2011

(PhysOrg.com) -- On the Earth, dust particles are everywhere - under beds, on bookshelves, even floating in the air. We take dust for granted. Dust is also common in space, and it is found for example in the ...

Hydrogen peroxide found in space

Jul 06, 2011

(PhysOrg.com) -- Molecules of hydrogen peroxide have been found for the first time in interstellar space. The discovery gives clues about the chemical link between two molecules critical for life: water and ...

Water vapor in space

Feb 04, 2011

(PhysOrg.com) -- Water is a critical molecule for human life, and, because it is abundant in the interstellar medium, it also plays an important role in the life of molecular clouds and the stars and planets ...

Recommended for you

ESO image: A study in scarlet

12 hours ago

This new image from ESO's La Silla Observatory in Chile reveals a cloud of hydrogen called Gum 41. In the middle of this little-known nebula, brilliant hot young stars are giving off energetic radiation that ...

Astronomers: 'Tilt-a-worlds' could harbor life

Apr 15, 2014

A fluctuating tilt in a planet's orbit does not preclude the possibility of life, according to new research by astronomers at the University of Washington, Utah's Weber State University and NASA. In fact, ...

Pushy neighbors force stellar twins to diverge

Apr 15, 2014

(Phys.org) —Much like an environment influences people, so too do cosmic communities affect even giant dazzling stars: Peering deep into the Milky Way galaxy's center from a high-flying observatory, Cornell ...

Image: Multiple protostars within IRAS 20324+4057

Apr 14, 2014

(Phys.org) —A bright blue tadpole appears to swim through the inky blackness of space. Known as IRAS 20324+4057 but dubbed "the Tadpole", this clump of gas and dust has given birth to a bright protostar, ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

Bonkers
not rated yet Oct 31, 2011
This is interesting practical research on what happens on real surfaces.
I would have thought it was obvious that life started on interstellar grains - just the volume (actually area) alone dwarfs any "primordial soup" reaction area.
Not only that, there is no water around to dilute the reactants or to destroy unstable intermediaries.

More news stories

Meteorites yield clues to Martian early atmosphere

(Phys.org) —Geologists who analyzed 40 meteorites that fell to Earth from Mars unlocked secrets of the Martian atmosphere hidden in the chemical signatures of these ancient rocks. Their study, published ...

Red moon at night; stargazer's delight

Monday night's lunar eclipse proved just as delightful as expected to those able to view it. On the East Coast, cloudy skies may have gotten in the way, but at the National Science Foundation's National Optical ...

Down's chromosome cause genome-wide disruption

The extra copy of Chromosome 21 that causes Down's syndrome throws a spanner into the workings of all the other chromosomes as well, said a study published Wednesday that surprised its authors.

Ebola virus in Africa outbreak is a new strain

The Ebola virus that has killed scores of people in Guinea this year is a new strain—evidence that the disease did not spread there from outbreaks in some other African nations, scientists report.