Earth's old water indicates chance of life on other planets

Importance of water to life on earth means any other inhabited worlds would likely need it too

Scientists have confirmed that much of the water on earth is older than the sun — which could indicate the existence of life on other worlds.

Researchers found that much of the water on Earth and across the system predates the sun, which could mean that other planets in the had access to water as they were being formed. That would likely be required to sustain life on any of those planets, as it has done on earth, the researchers said.

The study, ‘The ancient heritage of water ice in the solar system’, was published in Science this week.

By looking at the gases, dust and ice that were around during the formation of the sun, and exploring how much of them were present in the earth, scientists were able to establish that much of the water was brought over from the environment that existed before the sun was formed.

When the Sun was young, it was surrounded by a large disk, the solar nebula, where the planets that now exist in the solar system came from. The team created models to simulate that disk and understand whether the ice was formed as new there, or whether it re-formed already existing water.

They found that the make-up of the water meant that it existed before, meaning that it had existed in interstellar space and so is not limited to planets that were created from the same disk as Earth.

Because what the researchers call life-fostering environments require water, the discovery can help them understand the origins of such planets and assess whether they are likely to exist elsewhere in the universe.

“By identifying the ancient heritage of Earth’s water, we can see that the way in which our solar system was formed will not be unique, and that exoplanets will form in environments with abundant water,” said Tim Harries, a professor at the University of Exeter and a member of the research team. “Consequently, it raises the possibility that some exoplanets could house the right conditions, and water resources, for life to evolve.”