In July 2011, NASA’s Jet Propulsion Laboratory revealed an astonishing discovery: astronomers found a massive cloud of water vapor around a quasar named APM 08279+5255. Located over 12 billion light-years away, this cloud contains water vapor equivalent to 140 trillion times all the oceans on Earth. At the time, NASA called it the largest and most distant reservoir of water ever detected in the universe.
But what’s really fascinating isn’t just the figure; it’s the nature of this “reservoir.”
What We Found
APM 08279+5255 is a quasar—a galaxy with an enormous black hole at its core. This black hole is about 20 billion times heavier than our Sun and shines with energy comparable to a thousand trillion suns. The intense light from this quasar heats the surrounding gas, creating conditions where we can spot the water vapor clearly.
Two separate research teams worked on this. Dariusz Lis, leading a team at Caltech, made the first detection using a powerful radio telescope. Later, Matt Bradford’s team at JPL discovered even more evidence, allowing them to calculate the total mass of water present. Their findings were published in the Astrophysical Journal Letters.
Why “Reservoir” Might Mislead You
The term “reservoir” can paint a misleading picture. When you hear 140 trillion oceans, it sounds like there’s a huge lake out there. In reality, the water vapor is incredibly diffuse, spread across a vast region that spans hundreds of light-years. It’s about 300 trillion times less dense than Earth’s atmosphere—making it very thin. So, while the total mass of water is massive, it doesn’t mean there’s a lot of it in any specific location.
To put it into perspective, the mass of water detected amounts to around 100,000 times the mass of our Sun. This tells us about the scale of water in that area, but not how “wet” it is.
A Glimpse into the Early Universe
Light from APM 08279+5255 has been traveling for over 12 billion years. We’re seeing it as it was when the universe was still young, less than two billion years after the Big Bang. The water we detected offers a snapshot of conditions from that early time.
Interestingly, scientists expected to find water vapor in the universe’s infancy, which means their discovery doesn’t overturn any previous theories. Instead, it serves as a valuable tool for understanding how gas was distributed around early galaxies.
Is It Really the “Largest Ever”?
When we describe this as the “largest reservoir ever discovered,” it’s based on what our instruments have measured so far, not a claim on the entirety of the universe. If we looked at more areas of the sky or used different methods, we might find even larger concentrations of water.
Now, more than a decade after this finding, it remains a pivotal reference, highlighting that water was abundant in the young universe. This reinforces the idea that when conditions are right, even early and distant gases can reveal secrets about our cosmos.
Conclusion
The discovery of this vast amount of water vapor around APM 08279+5255 shows us that we are still learning about our universe. We can’t see everything, but even the smallest findings can have a big impact. By understanding how quasar environment influences elements like water, scientists can piece together the history and evolution of galaxies.
For more details on this groundbreaking discovery, check out the original JPL release.
