NASA's James Webb telescope detects water vapor in planet-forming region
An interesting new study, published in the journal Nature, has claimed that rocky exoplanets could contain vast amounts of water from the time they are born. This finding is based on a planetary system called PDS 70, which is located 370 light-years from us. The latest investigation was made possible because of the powerful James Webb Space Telescope (JWST).
Why does this story matter?
In the hunt for life-supporting planets beyond our solar system, water is a key component scientists look out for. This is because, on Earth, life flourishes almost everywhere where water is present. Now that astronomers have found that water could be present as rocky exoplanets start to form, it could help us better understand how our home planet came to possess the vital ingredient.
PDS 70 system contains a distinctive inner and outer disk
The PDS 70 system contains a host star with planets in orbit around it, like our solar system. The host star in this planetary system—also called PDS 70—is about three-quarters of the Sun's mass. This system comprises inner and outer disks composed of gas and dust which are separated by a gap of eight billion kilometers. Within this gap lie two giant planets.
Water vapor was detected in PDS 70's planet-forming region
Using Webb, researchers have detected water vapor in the PDS 70 system's inner disk, under a distance of 160 million kilometers from the host star. Astronomers believe this is the region where rocky, Earth-like planets may be forming. "This is the first detection of water in the terrestrial region of a disk already known to host two or more protoplanets," according to NASA.
'Such measurements were not possible before Webb'
"We've seen water in other disks, but not so close in and in a system where planets are currently assembling. We couldn't make this type of measurement before Webb," said Giulia Perotti, the study's lead author from Max Planck Institute for Astronomy (MPIA), Germany.
PDS 70 system is relatively old to contain planet-forming disks
PDS 70 is roughly 5.4 million years old. It is relatively old in terms of stars with planet-forming disks, making the discovery of water vapor surprising. "As previous studies failed to detect water in the central regions of similarly aged disks, astronomers suspected it might not survive the harsh stellar radiation, leading to a dry environment for the formation of rocky planets," per NASA.
Surrounding material could be shielding water in PDS 70
So what explains the presence of water in PDS 70? "Most likely, surrounding material such as dust and other water molecules serves as a protective shield. As a result, the water detected in the inner disk of PDS 70 could survive destruction," said NASA.
Astronomers have also found silicates in the system
It's important to mention that till now, astronomers have not detected any planets forming in the inner disk of PDS 70. To make that kind of discovery, researchers would need larger telescopes like the Atacama Large Millimeter/submillimeter Array (ALMA) located in Chile, South America. However, they have found the presence of building blocks, specifically silicates, for the creation of rocky worlds in the system.
Astronomers intend to further study PDS 70 using Webb
The detection of water vapor in the inner disk of the PDS 70 system implies that if rocky planets are birthed in that region, they would have access to water right from the very beginning. Scientists are going to carry out further investigations on PDS 70 using more of Webb's onboard instruments, which should provide more insights into the matter.
