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(CNN)A nearby star system is helping astronomers unravel the mystery of how water appeared in our solar system billions of years ago.
Scientists observed a young star, called V883 Orionis, located 1,300 light-years away using the Atacama Large Millimeter/submillimeter Array of telescopes, or ALMA, in northern Chile.
The star is surrounded by a planet-forming disk of cloud of gas and dust leftover from when the star was born. Eventually, material in the disk comes together to form comets, asteroids and planets over millions of years.
A team of researchers used ALMA to measure chemical signals in the planet-forming disk, and they detected gaseous water, or water vapor. Their detection allowed the astronomers to trace the water's journey from the gas clouds that formed the star and will eventually give rise to planets.
A diagram illustrates how a cloud of gas collapses to form a star with a disk around it. Then, the material creates a disk around the star, where planets will form.
Their findings, published Wednesday in the journal Nature, suggests that comets formed from the sun's planet-forming disk could have brought water to Earth. That means the water on Earth could actually be older than our sun, which is 4.6 billion years old.
"We can now trace the origins of water in our Solar System to before the formation of the Sun," said lead study author John J. Tobin, an astronomer at the National Radio Astronomy Observatory, in a statement.
Typically, water molecules are made of one oxygen atom combined with two hydrogen atoms.
The research team studied a variation called heavy water, detected in V883 Orionis' disk? where one of the hydrogen atoms is replaced by a heavy isotope called deuterium. The water we're used to and heavy water both form in different scenarios, and their ratios can be used by researchers to trace when and where the water molecules formed.
Astronomers believe comets might have been responsible for delivering water to Earth early in its history by colliding with the planet because some comets have ratios similar to water on Earth.
Comets are large celestial objects made of dust and ice that orbit stars.
During their study of V883 Orionis, the researchers realized the missing link between the young stars born from clouds of gas and dust that include water molecules, and the comets also created from those same clouds swirling around newborn stars.
Astronomers used ALMA to detect water (left, orange) dust (middle, green) and carbon monoxide (blue, right) in the planet-forming disk.