Water is one of the basic molecules in the process of forming stars and planets, as it is necessary for the crystallization of materials and the formation of solid bodies from the primary planetary disks, which provide stars with the gases necessary for their formation, and from them planets and comets are formed.
Although scientists don’t know exactly how water molecules reached planets and comets, they were able to detect a strong signal of water in the protoplanetary disk surrounding a young sun-like star called V883 Orionis, which will help determine the origin of planetary and cometary water.
protoplanetary disks
This signal helped scientists confirm that the water in the protoplanetary disk that helped form stars existed even before the stars were born in the protoplanetary disks, and it is also the same water that helped form planets and comets.
This means that the origin of water goes back to protoplanetary disks. Like other protoplanetary disks, V883 Orionis consists of cosmic gas and dust and is the birthplace of the planets that will orbit this young star, which is no more than half a billion years old (for comparison, the Earth’s sun is about 4.6 billion years old).
The water detected in V883 Orionis bears a chemical signature that explains the water’s journey through star-forming gas clouds to planets.
V883 Orionis is a planet-forming disk located about 1,300 light-years from Earth. This type of disk is formed when a cloud of gas and dust condenses into a star core at its center.
Around that star, the cloud material also forms in the form of a disk, and over the course of a few million years, the material in the disk gathers together to form comets, asteroids, and eventually planets, and fuels the star itself with the gas needed to form it.
The origin of the water
John Tobin, a researcher at the American Observatory for Radio Astronomy, said, “Our sun formed from a similar protoplanetary disk when our solar system was forming, which means that studying the water around that star will lead to a better understanding of how There is water in our solar system.
In exclusive statements to Al-Sharq, Tobin indicated that the study “supports the idea that water on Earth is older even than the sun, as it has interstellar origins, as the study confirms that water was present in the primary planetary disk, before the star itself was formed.”
Tobin and his team used data from the European Southern Observatory to measure the chemical signatures of water and its trajectory of star and planet formation.
The missing link
Ordinary water consists of one atom of oxygen and two atoms of hydrogen. Tobin studied a slightly heavier version of water, in which one of the hydrogen atoms is replaced by deuterium, a heavy isotope of hydrogen that contains a proton and a neutron instead of the one proton in a normal hydrogen atom.
Because normal and heavy water form under different conditions, their ratio can be used to track when and where water formed.
For example, this ratio has been shown in some solar system comets to be similar to that of water on Earth, indicating that comets may have delivered water to Earth.
Scientists previously studied the journey of water from disks to young stars, and then later to comets to planets, but until now the link between young stars and comets was missing.
V883 Orionis is the missing link in this case, Tobin said. The composition of water in protoplanetary disks is very similar to that of comets in our solar system.
This confirms the idea that water in planetary systems was formed billions of years ago, in interstellar space, and was then distributed to both comets and Earth.
Ice and gas
But verifying this idea was very difficult, as the chemical signature of water in protoplanetary disks is difficult to reach.
And the water in the disks that make up the planets is mostly in the form of ice, so it is usually hidden from our view. Detecting water in its gaseous form is easy thanks to the radiation emitted from the particles during their rotation and vibration, but discovering it is more complicated when it turns into ice, where the movement of the particles is more restricted. .
Gaseous water can be found towards the center of the disks, near the star, where it is warmer. However, these regions near the center of the disk are hidden by the dust disk itself, and are also too small to be imaged with telescopes.
Fortunately, the disk of V883 Orionis turned out to be unusually hot in a recent study. A chain of explosions inside the star heats the disk to a temperature where it is not water in the form of ice, but a gas, which enabled scientists to detect it.
Thanks to the sensitivity of the European Space Agency’s telescopes and their ability to distinguish small details, scientists were able to discover water and determine its composition, as well as determine its distribution within the disk, and they found that this disk contains at least 1200 times the amount of water in all the Earth’s oceans.
older than the sun
In his statements to Al Sharq, Tobin stated that the formation of water in the V883 Orionis disk was very similar to the younger and newborn protostars that had just formed, and it is also similar to the formation of water on comets in our solar system.
And he pointed out, “It is important to study water in star systems, and this naturally attracts us to understand the origins of the same water that we have on Earth and other places where we find water in the solar system, because wherever there is water in its liquid form, there may be (or there may be) There (was) life.”
The study also helps to better understand planets around other stars that may support the existence of life and water, as Tobin indicated that this discovery is “a cause for reflection.”
He said, “I suppose that the next time someone fills a glass of water or goes for a swim, they should realize that the molecules that make up the water they are enjoying are not only older than the sun itself, but they also formed in interstellar space and were part of the system.” protostellar, then protoplanetary disk, comets or asteroids.