- Astronomers have discovered the “missing link” in the journey of extraterrestrial water to Earth by studying the planetary formation disk around the star V883 Orionis, located about 1,300 light-years from Earth, using the ALMA telescope located in Chile.
- By studying the composition of the water present in the disk and detecting water in the form of gas, the researchers were able to trace the origins of water in our solar system back to before the formation of the Sun in interstellar space, confirming that the water in planetary systems was formed billions of years ago.
- Most of the water in the planetary formation disks is frozen as ice, which makes it difficult to detect. However, the unusually high temperature of the V883 Orionis disk made it easier to locate water in the form of gas, allowing astronomers to uncover the link between young stars and comets in water formation.
It was known that water had an extraterrestrial origin that arrived in the Solar System and later to the Earth that, helped life to emerge; however, the process had a “missing link” that would indicate that water had traveled through outer space even before the Sun of our stellar system was formed. In this regard, a group of astronomers detected the point that led to pronouncing such a conclusion.
The discovery was made through the ALMA telescope in Chile while studying the composition of the water in a planetary formation disk located about 1,300 light-years from Earth. This structure is located on the star V883 Orionis. The study is by astronomer John J. Tobin of the U.S. National Radio Astronomy Observatory, who published the finding Wednesday in Nature.
“We can now trace the origins of water in our solar system back to before the Sun formed.”
John Tobin
The team of astronomers under Tobin’s guidance detected water in the form of gas in the planet-forming disk surrounding the star V883. So when a cloud of gas and dust collapses, it forms a star at its center; around the star, the cloud material also forms a disk. Over the course of a few million years, the matter in the disk clumps together to form comets, asteroids, and eventually planets, the study explains.
Tobin and his group studied a slightly heavier version of water where one of the hydrogen atoms is replaced with deuterium, a heavy isotope of hydrogen, as opposed to simple water, which is composed of two hydrogen atoms and one oxygen atom. Because plain and heavy water forms under different conditions, their ratio can be used to track when and where water forms.
The challenges of detecting water in space
The process of identifying how water travels in space, from clouds to stars to comets to planets, had already been established; however, the link between young stars and comets was still unknown until today.
“In this case, V883 Orionis represents the missing link. The composition of the water in the disk is very similar to that of comets in our own solar system.”
John Tobin
Tobin added: “This confirms the idea that the water in planetary systems was formed billions of years ago, before the Sun, in interstellar space, and has been inherited by both comets and the Earth with relatively little change.”
Most of the water present in the planetary formation disks is frozen as ice, which makes it difficult for the naked eye to locate the remains of water, and even more so when in this solid state, its molecules do not rotate or vibrate rapidly as they normally do, which causes them to produce slight radiation that makes their presence detectable.
Water in the form of gas can be found towards the central region of the disks, close to the star, where the temperature is higher. However, these nearby regions are hidden by the dust disk itself and too small to be picked up by our telescopes.
Fortunately, the astronomers said, the recent study found that the V883 Orionis disk is at an unusually high temperature, making water less difficult to find.