Earth's water came from super deep space, and it's older than you can imagine
The water you drink may be older than the sun.
Astronomers announced the first evidence that links the water in our solar system to water in the vast reaches of space between the stars, known as the "interstellar medium." To do this, scientists were able to closely observe a young, forming star (a protostar) some 1,305 light-years away, along with the disk of gaseous material forming around it. They found this nascent solar system isn't simply flush with water; crucially, this distant water has the same distinct chemical markers as water in our solar system. It's billions of years old.
"This means that the water in our Solar System was formed long before the Sun, planets, and comets formed," Merel van ‘t Hoff, an astronomer at the University of Michigan who coauthored the new research published in Nature, said in a statement. (The sun, a medium-sized star, is 4 billion years old.)
"We already knew that there is plenty of water ice in the interstellar medium," van ‘t Hoff added. "Our results show that this water got directly incorporated into the Solar System during its formation. This is exciting as it suggests that other planetary systems should have received large amounts of water too."
The water found swirling around this distant protostar, called V883 Orionis, contains very similar ratios of hydrogen and a form of hydrogen called deuterium to the water in our solar system. This is a strong chemical fingerprint showing a close relationship between these disparate waters.
"This is exciting as it suggests that other planetary systems should have received large amounts of water too."
Tweet may have been deleted (opens in a new tab)
Sleuthing out evidence that our solar system's water came from interstellar space has been elusive. But the protostar V883 Orionis finally provided an exciting opportunity. Astronomers use radio telescopes — with giant antenna dishes — to observe the disks of matter forming around protostars. Importantly, they're looking for a zone dubbed the "snow line," where water ice becomes gas. This gives them the best, most detailed H2O information. If this snow line is too close to the star, it becomes impossible to peer through the dusty center of the forming solar system. But in V883 Orionis, the snow line is farther away, allowing the researchers rich insight into the developing solar system's water.
The astronomers used the powerful telescopes at the Atacama Large Millimeter/submillimeter Array, or ALMA, located at over 16,000 feet of elevation in Chile, to view water around V883 Orionis. These telescopes detect wavelengths of light (long wavelengths of light that we can't see) from giant clouds in deep, interstellar space. "Astronomers can use [this light] to study the chemical and physical conditions in molecular clouds — the dense regions of gas and dust where new stars are being born," the European Southern Observatory's ALMA website explains. "Often these regions of the Universe are dark and obscured in visible light, but they shine brightly in the millimetre and submillimetre part of the spectrum."
Want more science and tech news delivered straight to your inbox? Sign up for Mashable's Top Stories newsletter today.
In the deep cold of interstellar space, water freezes into ice on dust particles in these cosmic clouds. Eventually, when this dust collapses and coalesces around a young star, like V883 Orionis, the water gradually accumulates on comets, asteroids, moons, and planets. In our solar system, for example, some of the moon's craters are brimming with water ice, an expansive ocean sloshes over Earth, icy comets zoom through our cosmic neighborhood, and deep oceans likely exist underneath the icy shells of the moons Europa and Enceladus.
And this water, the researchers say, came from many light-years away, in far-off cosmic clouds.