Life first emerged on our planet roughly four billion years ago. For a long time, scientists have wondered where the building blocks of life cooked up. If the essential ingredients of life were formed in space and crash landed on Earth, there is a pretty good chance these ingredients have also been transported elsewhere. Now scientists have found further evidence that your genetic blueprint may have come to our planet from elsewhere.
Ribose sugar is the backbone of our genetic blueprint
In the past, life’s building blocks such as amino acids and nitrogenous bases (part of your genetic blueprint) have been detected in samples from comets and meteorites, or produced under comet-like conditions in the lab. But until now, nobody knew how ribose could have emerged from the solar nebula that preceded our solar system. Ribose sugar is the backbone of RNA and DNA in all living organisms.
Scientists at the Université Nice Sophia Antipolis in France shone UV light on a frozen mixture of chemicals, mimicking the comet ice in space, to produce ribose sugar in the lab. Lead author Cornelia Meinert said the sugars including ribose may have been there in all the experiments conducted around in the world in the last few decades. Meinert was able to detect them because she used the multidimensional gas chromatography.
How scientists produced ribose
Findings of the study were published in the journal Science. Researchers mixed ammonia and methane with water, which was then subjected to a temperature of -195 degrees Celsius and low pressure in a vacuum chamber. Then, just as “pre-cometary ice” might settle around dust grains in outer space, scientists allowed it to condense on a cold surface. As the material condensed, they bombarded intense UV light on it to let the mixture warm up, mimicking the UV light emitted by the young sun.
And the result was ribose and a variety of other complex molecules such as amino acids, alcohols, acids, aldehydes, and other sugars. Meinert said the results were consistent with finding of organic molecules on a comet. The European Space Agency’s Philae lander that reached Comet 67P in late 2014 had found organic molecules on the comet. Now researchers believe sugars like ribose could be surprisingly common in space. So, there is a pretty good chance our genetic blueprint may have reached Earth from space.