While life was once thought to just be a happy accident by mainstream science, the building blocks of DNA and RNA are proving to be not only tenacious, these organic molecules also appear to be able to form in the most unlikely of places, including in deep space on the surface of comets.
In 2014, the Philae lander touched down on the comet 67P/Churyumov-Gerasimenko, and during it’s investigation of the comet’s chemical makeup, it detected the presence of 16 types of organic compounds. These findings prompted the development of an organics detector for the lander, which led to experiments that simulated the chemical makeup and environmental conditions of the comet to determine what could be found there.
Experiments were conducted to simulate 67P’s conditions, involving a mix of water, methanol and ammonia, that were subjected to a low temperature and pressure environment, then irradiated with ultraviolet light. The result was that numerous organic residues formed, including three organic compounds that the Philae lander previously detected. And although the lander didn’t report finding this, the lab-grown comet produced a compound called ribose, a simple sugar carbohydrate. This is important, because ribose compounds form the backbone of RNA, and a related compound, deoxyribose, is found in DNA.
“The identification of ribose and related sugar molecules in the simulated cometary ice is new and entirely unexpected,” explains astrochemist Cornelia Meinert, from the University of Nice Sophia Antipolis in Nice, France. This finding offers valuable insight into the formation of life-giving compounds in the early solar system, and suggests that life, or at least the chemical building blocks necessary for it, could be common throughout not only the solar system, but the rest of the universe as well.