Space dust, asteroids and comets can account for all water on Mercury

Mercury has water ice in the shadows of its craters. It's not clear how those water molecule ended up on Mercury. A new simulation shows that asteroids, comets and dust particles carry enough water to account for all the ice sheets present. The study could lead to new research on water in exoplanetary systems. The work was published in a magazine.

We have known for a long time that Mercury has water. This can only be in the form of water vapor. The planet has no atmosphere so we can't rule out a liquid. Mercury is three times closer to the sun than the Earth is. There are craters. The troughs that are forever captured in darkness are illuminated by the band of the Milky Way against the backdrop of an eternal black sky. The closest planet to the sun is home to ice sheets many meters thick. How did those water molecule end up on Mercury?

Kateryna Frantseva is the first author to develop an algorithm that mimics meteorite impacts in the form of asteroids, comets and interplanetary dust particles. Over the course of a billion years, these bodies bring enough water to Mercury to explain how much we see.

Frantseva said, "We can't rule out natural sources of water such as volcanic activity and outgassing from the crust and mantle, but this shows that we don't need anything other than impacts from minor bodies to explain the water we see on Mercury." Each year, asteroids and comets deliver about a thousand kilograms.

New theoretical models for water delivery to exoplanets are provided by the simulation. Astronomers might be able to spot water signatures in the spectrum of light that asteroid belts emit while re-radiating light from their host star, if they can be compared to future observations.

More information: Kateryna Frantseva et al, Exogenous delivery of water to Mercury, Icarus (2022). DOI: 10.1016/j.icarus.2022.114980 Journal information: Icarus Citation: Space dust, asteroids and comets can account for all water on Mercury (2022, April 19) retrieved 19 April 2022 from https://phys.org/news/2022-04-space-asteroids-comets-account-mercury.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.