Organic molecules necessary for life found around newly formed stars

(CN) — Inside rings of matter orbiting newly formed stars, scientists have found large reservoirs of organic molecules necessary to form the basis of life, suggesting the basic conditions necessary to form life on Earth could exist in other parts of the galaxy.

A similar ring, or disk, would have once surrounded the sun in its early stages, the matter inside of which would have provided the building blocks for the formation of the planets that now make up our solar system.

For example, the disk — called a protoplanetary disk — that surrounds a young planet will “feed” it with material as it forms, and a young Earth is thought to have been seeded with material from the impacts of asteroids and comets that were formed in the protoplanetary disk around the sun.

So finding organic molecules inside these disks is significant because they are the stepping stones between simpler carbon-based molecules, such as carbon monoxide — which is found in abundance in space — and more complex molecules that are required to create and sustain life.

“Laboratory and theoretical studies have suggested that these molecules are the ‘raw ingredients’ for building molecules that are essential components in biological chemistry on Earth, creating sugars, amino acids and even the components of ribonucleic acid (RNA) under the right conditions,” John Ilee, research fellow at the University of Leeds in England, said in a statement.

But while these molecules are found in various environments throughout space, scientists have been uncertain whether all protoplanetary disks contain reservoirs of complex organic molecules capable of creating biologically significant molecules.

Now, a study published Wednesday in the Astrophysical Journal Supplement Series is beginning to answer that question.

To find the molecules, a team of astrophysicists from 16 universities across the world looked for the molecules’ “fingerprints.”

Every molecule absorbs and emits light in a unique wavelength — its “fingerprint” — determined by its arrangement of atoms and electrons. If scientists know a molecule’s specific wavelength, they can identify its presence and investigate its properties.

Using data collected by the Atacama Large Millimetre/submillimetre Array, or ALMA, radio telescope in Chile, scientists studied the existence, location and abundance of three molecules needed for life to form.

They looked at five protoplanetary disks between 300 and 500 light years away from earth and found molecules in four of them and in a greater abundance than expected, according to the study. The research is one of 20 papers reporting on a major international investigation into the chemistry of planet formation.

 “ALMA has allowed us to look for these molecules in the innermost regions of these disks, on size scales similar to our solar system, for the first time,” Ilee said. “Our analysis shows that the molecules are primarily located in these inner regions with abundances between 10 and 100 times higher than models had predicted.”

Additionally, the regions in which the molecules were found within the disks are also where asteroids and comets form, something Ilee says could indicate that a process similar to Earth’s creation could also happen in these disks.

“The key result of this work shows that the same ingredients needed for seeding life on our planet are also found around other stars,” said Catherine Walsh of the Leeds school of physics and astronomy and who also was involved in the study. “It is possible that the molecules that are needed to kick-start life on planets are readily available in all planet-forming environments." 

The next step for researchers is to investigate whether more complex molecules exist in protoplanetary disks.

“If we are finding molecules like these in such large abundances, our current understanding of interstellar chemistry suggests that even more complex molecules should also be observable,” Ilee said. “We’re hoping to use ALMA to search for the next stepping stones of chemical complexity in these disks. If we detect them, then we’ll be even closer to understanding how the raw ingredients of life can be assembled around other stars.”

Follow Rosana Hughes on Twitter

Follow @@HughesRosana