For the first time, the five basic rules from which life on Earth could have originated were found in meteorites.

One version of the panspermia hypothesis states that comets, asteroids, or meteorites brought biological life to Earth. Indeed, earlier in meteorites that fell to Earth, scientists discovered a number of organic compounds, including three essential for the formation of DNA and RNA: the nitrogenous bases adenine, guanine and uracil. It remains to find the previously elusive bases of cytosine and thymine, and the question of the origin of extraterrestrial life will shine with new colors. And it seems to have worked.

Image source: NASA Goddard / CI Lab / Dan Gallagher

Traditionally, organic compounds were investigated in meteorite material using superheated formic acid. The crushed parts of the meteorite were placed in acid, and after everything organic was dissolved there, an analysis was carried out. The nitrogenous bases adenine, guanine and uracil, which belong to the complex purine molecules, were found in meteorite samples without much difficulty, while the other two major compounds, cytosine and thymine, were not found as simpler hierarchical molecules.

In the new study, scientists used a cold water-based solution to dissolve the organic matter in the meteorite’s material. Also, for the analysis, a device was used that makes it possible to study the molecular structure of an order of magnitude or up to two orders of magnitude greater sensitivity. The new approach was justified: For the first time, both cytosine and thymine were found in samples from three meteorites. This confirms that all five basic elements for the formation of DNA and RNA could have arrived on the young Earth along with the cosmic bodies.

Scientists hope to similarly study material from asteroids, which will be delivered to Earth by the Hayabusa2 and OSIRIS-REx automated stations. This will be a pure science experiment because the samples will not be accidentally contaminated when they enter Earth’s atmosphere and will be delivered to the surface in airtight capsules.