At 12 billion light-years from Earth, NASA has detected a massive water reservoir containing 140,000 trillion times the amount of water on Earth.

Far away. Very far away. Some 12 billion light years away, in a remote corner of the universe, lies an unimaginable reservoir of water.

140 trillion oceans. 140 trillion times (in imperial units) the volume of all the oceans on Earth combined. The largest and most distant reservoir of water ever identified in the universe.

This colossal reservoir of water orbits a quasar whose light reached us shortly after the Big Bang. “This is further evidence that water is widespread throughout the universe, even in its earliest stages,” said one of its discoverers, scientist Matt Bradford of NASA’s JPL laboratory.

A supermassive black hole

The quasar, called APM 08279+5255, surrounds a black hole 20 billion times more massive than the Sun, producing as much energy as a thousand trillion suns.

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This central black hole attracts surrounding matter, heating the gas and dust to create a region full of molecules never before detected at such an extreme distance. Water vapour is one of these molecules, and its presence indicates that the quasar is emitting radiation, as it keeps the surrounding gas relatively warm.

What is a quasar?

These objects were named in the late 1950s, when telescopes of the time revealed mysterious sources of intense brightness in distant regions of space. They shine brightly from the centres of distant galaxies, outshining all the stars in their galaxy.

At the heart of these galaxies is a supermassive black hole with a mass millions or even billions of times greater than that of our sun. As gas and dust spiral towards the black hole, they heat up and release energy. This energy is radiated at all wavelengths, making quasars one of the brightest and most energetic phenomena in the cosmos.

This is what makes it so special. Astronomers have discovered that water vapour extends over an area of several hundred light years around the quasar. Given that a light year is equivalent to 9 trillion kilometres, there is no other water reservoir as massive and as distant.

This exceptional reservoir is made possible by the unusual conditions surrounding it: the gas is five times hotter and hundreds of times denser than in typical galaxies. Astronomers have also detected other molecules, such as carbon monoxide, suggesting that the black hole is being fed abundantly with matter as it grows.

Why is this important?

Studying quasars allows astronomers to learn more about the early universe, because the light we can observe from Earth has travelled billions of years before reaching us.

Due to their intensity, quasars provide invaluable information about galaxy formation, the distribution of matter, and the development of the first cosmic structures. The detection of water in such a distant quasar is particularly important, as it is an essential element for life.