Comets Could Deliver Life's Building Blocks to Exoplanets, Study Suggests

Slow-moving comets in 'peas in a pod' systems could deposit prebiotic molecules on other planets, according to University of Cambridge researchers.

Researchers from the University of Cambridge have proposed a theory that comets could deliver the building blocks for life to other planets in the galaxy, particularly in 'peas in a pod' systems where planets orbit closely together.
To deliver organic material, comets need to be travelling relatively slowly -- at speeds below 15 kilometres per second. At higher speeds, the essential molecules would not survive -- the speed and temperature of impact would cause them to break apart.
Comets are known to contain a range of the building blocks for life, known as prebiotic molecules. For example, samples from the Ryugu asteroid, analysed in 2022, showed that it carried intact amino acids and vitamin B3.
The researchers used mathematical modelling techniques to determine that it is possible for comets to deliver the precursor molecules for life, but only in certain scenarios. For planets orbiting a star similar to our own Sun, the planet needs to be low mass and it is helpful for the planet to be in close orbit to other planets in the system.
The researchers' findings could be useful when determining where to look for life outside the Solar System.