Building blocks for life on Earth found in distant cloud of stardust
WHEN Carl Sagan, the late American astrophysicist, made the comment that “we are made of star-stuff” he meant that all the elements on Earth were once produced in the heart of stars before being flung out into the universe in giant supernovae.
But scientists have now discovered that the actual building blocks for life itself are also found floating in stardust.
Researchers from Queen Mary University of London and University College London discovered an organic compound, which is forming new stars 400 light years away in the constellation Ophiuchus, The Serpent Bearer.
The area of space is significant because it is a mirror image of how our own solar system formed billions of years ago, suggesting that life in our section of the universe probably got going in a similar way. It also means life elsewhere is more likely.
The compound methyl isocyanate comes from a family of molecules that are the foundation of vital molecular mixtures such as peptides and amino acids, which are essential for living organisms on Earth.
Scientists have long suspected that organic compounds were brought to Earth via comets which crashed into the planet. But it was unclear where they had come from in the first place.
The latest discovery suggests they may form in the melting pot of new stars. “This family of organic molecules is involved in the synthesis of peptides and amino acids, which, in the form of proteins, are the biological basis for life as we know it,” said Audrey Coutens at UCL.
Dr David Quénard, from QMUL’S school of physics and astronomy, added: “Our findings indicate that the key ingredients for the origin of life could have been produced at an early stage of the solar system. It is believed that some basic prebiotic chemistry could have developed in space, likely transferring prebiotic molecules to the solar nebula and later on to Earth.”
Earth and the other planets in our solar system are formed from the material left over after the formation of the Sun about 4.5billion years ago.
So finding complex molecules at the birth of a star indicates that all the planets created around it are surrounded with the chemical ingredients needed to make life.
Organic molecules created in clouds of interstellar gas and dust during the early stages of star formation could have easily been transferred to planets and smaller bodies, such as asteroids.
Dr Izaskun Jiménez-serra, from QMUL, said: “Our results suggest that the chemical composition of comets may be inherited directly from the interstellar medium.”
The team made the discovery using data from the Alma telescope (Atacama Large Millimeter/submillimeter Array) in Chile. They found the unique chemical fingerprints located in the warm, dense inner regions of the cocoon of dust and gas surrounding stars in their earliest stages of evolution.
Rafael Martín-doménech said: “We are particularly excited about the result because these protostars are very similar to the Sun at the beginning of its lifetime.”
Dr Niels Ligterink at the Leiden Observatory in the Netherlands also carried out experiments to prove that the chemicals could form in the icy depths of space. The findings were reported in the Monthly Notices of the Royal Astronomical Society.