NASA says distant exoplanet could have rare water ocean and possible hint of life | NASA

Scientists at NASA have announced the presence of a possible rare water ocean on a giant exoplanet dozens of light-years away, as well as a chemical hint of a possible sign of life.

The “interesting” discovery was made by the space agency’s James Webb Telescope, located 120 light-years from Earth in the constellation Leo, based on previous studies of the region using the previous Webb telescopes, Hubble and Kepler.

The researchers named the exoplanet K2-18 b, an ordinary nickname for something of this potential importance. NASA says this planet has a mass of approximately nine times that of Earth: “A Hessian-type exoplanet, a planet with the potential to have a hydrogen-rich atmosphere and a surface covered by a water ocean.”

The space agency said its observations of the chemical composition of the planet’s atmosphere indicate the possibility of the existence of an ocean world. “The abundance of methane and carbon dioxide, and the lack of ammonia, support the hypothesis that there may be a water ocean under a hydrogen-rich atmosphere in K2-18 b,” she said.

But the agency also hinted at a more notable possibility in the possible discovery of a molecule called dimethyl sulfide (DMS), which on Earth is produced only by life.

“The bulk of DMS in Earth’s atmosphere is emitted by phytoplankton in marine environments,” a NASA press release said.

However, the presence of DMS still needs to be confirmed, and requires further investigation. “Forthcoming Webb observations should be able to confirm whether DMS is indeed present in the atmosphere of K2-18 b at significant levels,” said Nico Madhusudan, an astronomer at the University of Cambridge and lead author of the NASA research.

This will not be the first time that NASA has found indications of the presence of water on other planets. Water vapor has previously been detected on a smaller exoplanet, HAT-P-11b, about the size of Neptune, located in the constellation Cygnus, also 120 light-years away.

But scientists are excited about the discovery, although they caution that it does not necessarily mean the planet can support life.

“Our findings underscore the importance of considering diverse habitable environments when searching for life elsewhere,” Madhusudan said.

“Traditionally, the search for life on exoplanets has focused primarily on smaller, rocky planets, but larger Hessian worlds are more suitable for atmospheric observations.”

The exoplanet orbits the cool dwarf star K2-18, has a diameter 2.6 times that of Earth, and is located in what NASA calls the habitable zone, a region around a star where planets with liquid water may exist.

NASA says its interior likely contains a large blanket of high-pressure ice, similar to Neptune, but likely with a thinner, hydrogen-rich atmosphere and an oceanic surface. Hessian worlds are expected to have oceans of water, but at K2-18 b it is also possible that the ocean would be too hot to live in.

The planet’s presence was first detected by NASA’s K2 mission in 2015, but Webb’s improved technology over previous telescopes has allowed for a more detailed analysis, revealing that it could be an oceanic world. Scientists were able to study a small portion of starlight as it passed through the outer planet’s atmosphere.

“This result was only possible due to the extended wavelength range and unprecedented sensitivity of the Webb, which enabled robust detection of spectral features with just two transits,” Madhusudan said.

“For comparison, one transit observation using the Webb provided a resolution comparable to eight Hubble observations made over a few years and in a relatively narrow wavelength range.”

NASA marked the first anniversary of the Webb Space Telescope’s operation in July by releasing an “unprecedented” close-up image of the closest star-forming region to Earth.

In just over a year, it has allowed humans to look closer into the origins of the universe than ever before, producing high-resolution images of distant worlds and the mysterious structures that surround them.

They include the “rare and fleeting” phase of a star on the cusp of death; The early galaxies formed only 350 million years after the big bang; Evidence of the existence of “cosmic-breaking galaxies” is much larger than scientists thought possible, with the potential to upend current theories of cosmology.