Ted Bergin: ‘Space clouds contain water enough to fill oceans’

Space clouds, many light-years in size, collapse to form stars and planets. Some may contain the building blocks of life.

Ted Bergin: The giant molecular clouds are light-years in size. They’re so large they sort of boggle the mind.

That’s astronomer Ted Bergin of the University of Michigan. He’s describing huge clouds of molecules in space that can eventually collapse to form thousands of stars and planets.

Ted Bergin: So we know that we’re seeing carbon monoxide, and we know that we’re seeing methanol, we’re detecting alcohol in space, and most importantly, water.

As a gas cloud in space collapses under its own weight, Bergin said that hydrogen and oxygen molecules combine and freeze as water ice on grains of dust. He added that a lot of water – enough water to fill oceans – collects as ice in planet-forming discs that surround young stars.

Ted Bergin: So the disc itself, and the cloud, will have thousands, perhaps tens of thousands of oceans of water. And a fraction of that gets incorporated into Earth-like planets.

Bergin also said that the building blocks of life – what scientists called ‘pre-biotic’ molecules – ride along with the ice in clouds during planet formation.

Ted Bergin: Now maybe they don’t have anything to do with the initial steps of life. But maybe they aided and sort of ‘jump-started’ the initial steps transitioning from chemistry to biology.

Bergin said that water actually makes it easier for stars to form in the first place. That’s because hotter objects tend to resist the gravitational forces trying to gather them up into star- or planet-shaped objects. And water, or ice, helps cool this process, enabling gravity to do its work.

Ted Bergin: So that’s why molecules are crucial, and water is a very important one. At some stages when things are collapsing to form stars, it’s a very efficient coolant. It keeps things cold so it’s easier for stars to be born.

He added that this work has important parallels to earthly processes.

Ted Bergin: To me it’s very exciting that one can dream of parallels between our own origins, the water in our bodies and the water we drink, with things that happened billions of years ago.

Our thanks to:
Edwin (Ted) Bergin
Professor of Astronomy
University of Michigan

Jorge Salazar