Astronomers find a cosmic reservoir with 140,000 trillion times Earth’s water supply

In the early universe, even a whisper of water vapor can upend what we think is possible. One distant quasar has just reminded us how wet—and weird—the cosmos can be.

An Ocean Beyond Imagination

It’s hard to grasp a body of water so immense it makes Earth’s oceans look like puddles. But this was not a “late-2024” discovery: astronomers reported it in 2011, when they identified the largest and most distant water reservoir then known.¹ Located more than 12 billion light-years away, it surrounds the brilliant quasar APM 08279+5255. The reservoir contains at least 140 trillion times all the water in Earth’s oceans—not “140,000 trillion.”²

At the quasar’s core is a supermassive black hole. Popular summaries often cite about 20 billion solar masses, but published estimates vary with method and lensing assumptions—so treat “~20 billion” as an estimate, not a fixed value.³ The quasar radiates roughly the energy of a thousand trillion Suns, an astonishing engine for the environment where this water resides.

Did you know?
NASA’s Matt Bradford said the quasar’s environment is “unique” in producing such a huge mass of water—evidence that water was widespread when the universe was still young.

A Galactic Oasis With Extreme Conditions

This isn’t water you could pour into a glass. Around APM 08279+5255, the vapor temperature sits near −53 °C (−63 °F)—not −63 °C—and the gas is roughly 10–100× denser than is typical in many galactic environments.⁴ The quasar’s intense X-ray and infrared output keeps the surrounding material warm and stirred, sustaining that vapor.

Some teams note there’s ample gas for continued accretion; depending on how much forms stars or is blown out, the black hole could keep feeding and grow substantially—best framed as a possibility, not a prediction.

Water Across The Cosmos

This find isn’t an outlier. Over recent decades, astronomers have spotted water in many settings:

• Protoplanetary disks: JWST detected water vapor in the inner, rocky-planet zone of PDS 70, the first such detection in a disk already known to host forming planets.
• Comets: ESA’s Rosetta watched comet 67P vent measurable water vapor—real-time proof that icy bodies shed water as they warm.
• Exoplanets: Hubble revealed water vapor in the atmosphere of K2-18 b, a milestone in characterising worlds beyond the Solar System.

What This Means For The Future

Finds like this shift the timeline: water was present in meaningful quantities when the universe was young. That raises testable questions: How often do quasar environments stockpile water? Do such reservoirs seed early galaxy growth or shape star- and planet-forming chemistry? As instruments sharpen, expect more of these galactic oases—each one linking cosmic chemistry to the conditions that might someday nurture life.

Footnotes

1. Astronomers Find Largest, Most Distant Reservoir of Water — NASA/JPL: https://www.jpl.nasa.gov/news/astronomers-find-largest-most-distant-reservoir-of-water/
2. Astronomers Find Largest, Most Distant Reservoir of Water — Lunar and Planetary Institute (NASA source): https://www.lpi.usra.edu/features/quasarWater/
3. A multi-epoch spectroscopic study of the BAL quasar APM 08279+5255 — Astronomy & Astrophysics: https://www.aanda.org/articles/aa/full_html/2016/03/aa27152-15/aa27152-15.html
4. Astronomers Find Largest, Oldest Mass of Water in Universe — Space.com (2011): https://www.space.com/12400-universe-biggest-oldest-cloud-water.html