The story that you will read next, like any good scientific story, more surprised by the hypotheses that open that not for certainties that it contributes. So get ready because this scientific discovery comes with curves. A team of Japanese astrobiologists announced on Tuesday the finding traces of uracil on the Ryugu asteroid, a celestial body that travels through space about 300 million kilometers from our planet. On Earth, uracil is one of the key pieces to form RNA so, in a way, it is considered as a key ingredient for life. But what happens when this substance is in space? Does this mean that a precursor to life has been found in space? This is where the story starts to get interesting.
The discovery supports the theory that the basic ingredients for life swarm the cosmos and only need to fall into the right place for ‘magic to happen’
For millennia humanity has wondered if we are alone in the universe. For this reason, in recent decades, more and more missions are focused on searching for traces of life beyond our planet. With this purpose in mind, in 2018 the Japanese Space Agency (JAXA) sent a spacecraft to the Ryugu asteroid. His goal was collect samples from this space body andtscrape them to earth for analysis. In December 2020, space rock fragments reached our planet. Their analysis, as explained by the scientists from the University of Japan who have led this latest study, has shaken the foundations of astrobiology. That is, the guide to understanding how life could have arisen in the universe.
In 2018, a Japanese spacecraft traveled to the asteroid, collected samples, and brought them back to Earth.
The analysis of various rock fragments from the Ryugu asteroid, published this Tuesday in the journal ‘Nature Communications’, has revealed the presence of uracil, niacin (vitamin B3) and other organic molecules which is considered as key pieces in the formation of more complex organic molecules. To give you an idea of what this means, it is as if each of these compounds were a small LEGO piece that, if placed in the correct order and shape, can form a much bigger and more complex construction. In the case of organic molecules, the hope is that one day their presence may help to understand how life formed on our planet. Or to find past, present or future forms of life beyond our world.
ingredients for life
But what does the uracil finding in Ryagu mean? Well, here begins the fun part of the story. The team led by Yasuhiro Oba suggests that the Basic pieces for life on Earth to form could be formed in space and reached our planet aboard carbon-rich meteorites. This hypothesis, known as panspermia, has also been supported by other studies carried out from Oba’s Japanese laboratory as well as by other international research groups. According to this theory, the basic ingredients for life to sprout already They are swarming through the cosmos and it just needs to drop in the right place at the right time for the ‘magic to happen’.
He discovery of uracil in ryagu could indicate that the basic ingredients for life to form on our planet could have an extraterrestrial origin. «This is an exciting discovery, as it reveals that uracil (one of the nucleobases of RNA) can be synthesized in space«, explains Izaskun Jiménez-Serra, senior scientist at the CSIC at the Center for Astrobiology in Madrid (CAB). According to this researcher at the Science Media Center (SMC), this finding suggests that this compound could have reached Earth through from the impact of meteorites between 4,100 and 3,800 million years ago and, from there, they would have «triggering the first biochemical processes que led to the origin of life«On earth.
«This is an exciting discovery»
Izaskun Jiménez-Serra, CSIC scientist
The panspermia hypothesis, although interesting, does not convince all scientists. In fact, some argue that the discovery of trace amounts of uracil on the Ryugu asteroid is, at bottom, a expected finding. «Ryugu’s analysis is not surprising and are consistent with analyzes of type meteorites carbonaceous chondrite and with what we know about the chemistry of these materials», highlights César Ángel Menor Salvan, astrobiologist and professor of biochemistry at the University of Alcalá. «What would have been a big surprise is if there was no uracil and other related molecules», highlights the scientist in statements to the Science Media Center Spain (SMC).
«This study is historic and represents a milestone in space research»
César Ángel Menor Salvan, astrobiologist
The astrobiologist argues that the importance of this work is, in fact, proof that we are capable of collecting samples from another body in the Solar System, bring them back to Earth and analyze them in detail. All this, creating a reliable protocol in the custody and handling of samples to avoid its contamination with terrestrial compounds. «This study is historic and represents a milestone in space research», highlights the scientist who, even so, qualifies that «as usually happens in this type of case, work leaves us with more questions than answers«.