07:38 GMT +321 September 2019
Listen Live
    Space

    New Study Indicates Shooting Stars Delivered Sugar of Life to Earth

    © Flickr/ Sweetie187
    Environment
    Get short URL
    363
    Subscribe

    Astrobiologists have found that ribose, a sugar needed to make RNA, may be one of many molecular building blocks of life that began in space and ended up on Earth as a result of strikes by comets or meteors.

    Scientists at the National Centre for Scientific Research (CNRS) in France have carried out a laboratory experiment that mimicked the conditions of the very early solar system, a disk-shaped cloud that formed the comets and planets

    They cooled down a mixture of chemicals – water, methanol and ammonia to a temperature of minus 195 degrees Celsius inside a vacuum chamber, and then shone ultraviolet light on the frozen mixture to warm it up again to room temperature, a process similar to that undergone by a comet when it approaches the Sun.

    The experiment resulted in the formation of a large variety of organic compounds, including ribose and other sugar molecules, suggesting that these molecular building blocks of life could have formed when similar ices condense around dust grains and comets, close to a young star.

    The sugar ribose is the principal constituent of RNA, a single-strand molecule that can also encode information like DNA and is hypothesized to have been used by early life to pass on genetic information, instead of DNA.

    A hairpin loop from a pre-mRNA. Highlighted are the nucleobases (green) and the ribose-phosphate backbone (blue). Note that this is a single strand of RNA that folds back upon itself
    © Photo : Wikipedia/Vossman
    A hairpin loop from a pre-mRNA. Highlighted are the nucleobases (green) and the ribose-phosphate backbone (blue). Note that this is a single strand of RNA that folds back upon itself
    The observations, which were published on Friday in the journal Science, support the idea that some of the molecules crucial to the origins of life could have formed in interstellar ices, and were then delivered to Earth by comets or meteors.

    Lead author of the study Uwe Meierhenrich told Chemistry World that the findings also hint that the genetic material of any life on other planets could potentially be based on different sugars.

    "We did not only detect ribose, but many other sugar molecules," he said.

    "[This] does not necessarily hint to RNA that preceded DNA and evolved from ribose. Alternative nucleotide precursors might have played their role in chemical evolution as well.’

    Astrochemist Scott Sandford added that the chemical complexity the scientists observed may give clues about the origins of life on Earth.

    "Modern life is very efficient – it uses RNA and DNA – but the original versions of proto-life almost certainly didn’t," he said.

    "Some of these other sugars that modern life doesn’t use may have actually played key roles back in the beginning."

    Related:

    As Cold as Ice and as Old as the Sun: Cool Findings on Comet Churi
    Doomsday Cometh: #StarbucksItalia Heralds the End for Anxious Italians
    This is the End: Outer Space Comets Could Destroy Humanity
    Tags:
    Solar System, comet, Space
    Community standardsDiscussion
    Comment via FacebookComment via Sputnik