A Universe Full of Complex Molecules

Asteroids are much smaller than comets, because they usually endure the heat and effects of liquid water. But these results can lead to new organic problems. For many years, scientists have known that meteorites called chondrites, which come from asteroids, have different types of molecules. The Murchison meteorite, which fell in Australia in 1969, contains more than 96 amino acids. Life uses 20 or more. Osiris-Rex and Hayabusa2 have confirmed that the asteroids Bennu and Ryugu are as complex as those meteorites. And some of these problems seem to have started on the same asteroids: A preliminary analysis a sample of Bennu shows that it stores organic matter, including polycyclic aromatic hydrocarbons, from the protoplanetary disk.

Chemistry of Life?

Organic molecules on the early Earth took a new, more surprising direction. They somehow they made themselves in something alive. Other hypotheses for the origin of life on Earth include the initial organic materials from space. The “PAH world” concept, for example, posits a part of the original soup that was dominated by polycyclic aromatic hydrocarbons. From this slurry the first genetic molecules emerged.

In general, understanding how complex life forms in space and ends up on planets can give us a better idea of ​​whether life once existed on other planets. If life on Earth was created in space, living things must be everywhere in nature.

At present, such assumptions are still unproven. But because life itself represents a new level of complexity, astronomers are searching for more complex life as a sign of life, or sign of life, in other worlds around our planet.

The European Space Agency’s Juice mission is about to study Jupiter and its five moons, and NASA’s Europa Clipper mission launched to one of those moons, Europa, in October. Both will use onboard instruments to search space for biological molecules, as will the future Dragonfly mission to Saturn’s moon, Titan.

However, it is difficult to determine whether molecules are given with a biosignature or not. If scientists found enough complex molecular structures, that would be enough to convince other researchers that we have found life on another planet. But as comets and asteroids show, the lifeless world is complex in itself. Chemicals thought to be biosignatures have been found in non-living rocks, such as the recently identified dimethyl sulfide Hänni group on 67P.