Researchers of the University of Cambridge have shown how comets can transport the molecular elements necessary for life to the planets, just as it is theorized that could have happened on Earth.
For comets to release organic material, They must travel at relatively slow speeds, less than 15 kilometers per second. At higher speeds, the fundamental molecules would not survive due to the speed and temperature of the impact that would break them.
Very compact planetary systems, like those that orbit a star, are considered likely places where comets could travel at the right speed. In these systems, comets could “bounce” from one planet’s orbit to another, slowing down.
When a comet moves slowly enough and hits the surface of a planet, it releases intact molecules that researchers believe are precursors to life.
Did they allow life on earth?
This new study, published in Proceedings of the Royal Society Asuggests that these systems could be promising areas to search for life beyond our solar system if the arrival of comets is crucial for the origin of life.
Comets are known to contain basic components for lifesuch as amino acids and vitamin B3, as demonstrated in the analysis of samples from the asteroid Ryugu in 2022. In addition, they contain significant amounts of hydrogen cyanide (HCN), another crucial molecule.
The resistance of HCN to high temperatures suggests its ability to survive atmospheric entry and remain intact.
Richard Anslowof the Cambridge Institute of Astronomypoints out that these molecules could have contributed to the origin of life on Earthwhich could possibly be applicable to other planets in the galaxy.
The researchers are not claiming that comets are essential to the origin of life on Earth or other planets, but rather are trying to narrow down the types of planets where comets could successfully transport complex molecules like HCN.
In the solar system, most comets are in the Kuiper belt and they can be pulled into the interior of the solar system by the gravity of Neptune and Jupiter.
However, scientists wanted to understand what types of kitestraveling at what speeds, could release intact prebiotic molecules on Earth-like planets.
Using mathematical models, the researchers conclude that comets could release these life-precursor molecules, but only under specific circumstances.
For example, nearby planets in compact systems they are more likely to interact with and capture comets, which could be crucial for the delivery of prebiotic molecules.
In contrast, systems with lower mass stars present additional challenges due to higher velocities and lower likelihood of interactions with comets.
Planets orbiting these stars could experience more high-speed impacts, which could pose unique difficulties for life in those environments.