Skip to main content
  1. Home
  2. Space
  3. News

James Webb detects water vapor in rocky planet’s atmosphere — maybe

Georgina Torbet
By

The hunt for habitable exoplanets is on, and with the James Webb Space Telescope, we finally have a tool that can not only detect the presence of a planet in another star system, but can also look at the composition of its atmosphere. That ability will eventually allow us to find Earth-like planets wthat are good candidates for searching for life, but measuring the atmosphere of something so far away isn’t an easy matter.

Webb recently saw exciting signs in the form of water vapor detected in the vicinity of the exoplanet GJ 486 b. That could indicate the presence of water in its atmosphere, but it could also be from another source: the outer layer of the planet’s host star. Researchers are working through the data and hope to use another of Webb’s instruments to make the final call.

This artist concept represents the rocky exoplanet GJ 486 b, which orbits a red dwarf star that is only 26 light-years away in the constellation Virgo. By observing GJ 486 b transit in front of its star, astronomers sought signs of an atmosphere. They detected hints of water vapor. However, they caution that while this might be a sign of a planetary atmosphere, the water could be on the star itself – specifically, in cool starspots – and not from the planet at all.
This artist’s concept represents the rocky exoplanet GJ 486 b, which orbits a red dwarf star that is only 26 light-years away in the constellation Virgo. By observing GJ 486 b transit in front of its star, astronomers sought signs of an atmosphere. They detected hints of water vapor. However, they caution that while this might be a sign of a planetary atmosphere, the water could be on the star itself and not from the planet at all. ILLUSTRATION: NASA, ESA, CSA, Joseph Olmsted (STScI), Leah Hustak (STScI)

The planet GJ 486 b is rocky, a bit larger than Earth, and more massive, so it would have heavier gravity than we experience. And the star it orbits is quite different from our sun, as it is a type called a red dwarf, which is a dim, cool star that is approaching the end of its life. The planet is close enough to the star, orbiting in just 1.5 days, that its surface temperature would be around 800 degrees Fahrenheit, so it isn’t in the habitable zone where liquid water can exist on the surface.

Related

However, Webb’s NIRSpec instrument detected water vapor, which could mean that the planet does have an atmosphere even though it’s so close to its star.

Related Videos

“We see a signal and it’s almost certainly due to water. But we can’t tell yet if that water is part of the planet’s atmosphere, meaning the planet has an atmosphere, or if we’re just seeing a water signature coming from the star,” explained Sarah Moran of the University of Arizona, lead author of the research, in a statement.

The reason that the star could be the source of the water vapor is that there are cool spots on the star’s surface, similar to the sunspots seen on our sun. The cool areas around these regions are more likely to collect water vapor compared to the hot regions around them, so there could be enough water vapor to give a signal to Webb’s instrument.

Finding water in the atmosphere of this rocky planet would be exciting since astronomers haven’t seen this before, and it could help to find habitable exoplanets in the future. But to be sure of the source of the water vapor, the researchers need to make more measurements using Webb’s NIRISS and MIRI instruments.

“Water vapor in an atmosphere on a hot rocky planet would represent a major breakthrough for exoplanet science,” said fellow researcher Kevin Stevenson of the Johns Hopkins University Applied Physics Laboratory. “But we must be careful and make sure that the star is not the culprit.”

The research will be published in The Astrophysical Journal Letters.

Editors' Recommendations

Topics
Georgina Torbet
Georgina Torbet
Space Writer
Georgina is the Digital Trends space writer, covering human space exploration, planetary science, and cosmology. She…
Webb uses a galactic megacluster as an enormous magnifying lens
Astronomers estimate 50,000 sources of near-infrared light are represented in this image from NASA’s James Webb Space Telescope. Their light has travelled through varying distances to reach the telescope’s detectors, representing the vastness of space in a single image. A foreground star in our own galaxy, to the right of the image center, displays Webb’s distinctive diffraction spikes. Bright white sources surrounded by a hazy glow are the galaxies of Pandora’s Cluster, a conglomeration of already-massive clusters of galaxies coming together to form a megacluster.

Modern space telescopes are tremendously powerful instruments, able to look deep into space without being limited by the blurring effects of Earth's atmosphere. But even this is not enough to allow them to see the most distant galaxies, which are so far away that looking at them is like looking back in time to the early stages of the universe.

To look even further out, astronomers take advantage of a phenomenon called gravitational lensing. This happens when an object like a galaxy or a galaxy cluster has so much mass that it bends space-time, acting like a magnifying glass and brightening the extremely distant objects behind it.

Read more
James Webb captures swirls of dust and gas in nearby galaxies
Scientists are getting their first look with the NASA/ESA/CSA James Webb Space Telescope’s powerful resolution at how the formation of young stars influences the evolution of nearby galaxies. The spiral arms of NGC 7496, one of a total of 19 galaxies targeted for study by the Physics at High Angular resolution in Nearby Galaxies (PHANGS) collaboration, are filled with cavernous bubbles and shells overlapping one another in this image from Webb’s Mid-Infrared Instrument (MIRI). These filaments and hollow cavities are evidence of young stars releasing energy and, in some cases, blowing out the gas and dust of the interstellar medium they plough into.

The James Webb Space Telescope is helping astronomers to peer into nearby galaxies and see the elaborate structures of dust and gas which are created by and necessary for star formation.

The Physics at High Angular resolution in Nearby Galaxies, or PHANGS project, involves using data from different telescopes to look at galaxies that are close to us. By using telescopes such as the Hubble Space Telescope and the Atacama Large Millimeter/submillimeter Array, researchers can collect data in different wavelengths such as the visible light and radio wavelengths.

Read more
James Webb Telescope catches a glimpse of young version of the Milky Way
This image shows an artist impression of our Milky Way galaxy in its youth. Five small satellite galaxies, of various types and sizes, are in the process of being accreted into the Milky Way. These satellite galaxies also contribute globular star clusters to the larger galaxy. The Sparkler galaxy provides a snap-shot of an infant Milky Way as it accretes mass over cosmic time.

Data from the James Webb Space Telescope has given a glimpse into what our galaxy was like in its formative years. Webb observed a galaxy called The Sparkler, which is analogous to what the Milky Way would have been like when it was young, when it had less mass and only a handful of globular clusters.

This image shows an artist impression of our Milky Way galaxy in its youth. Five small satellite galaxies, of various types and sizes, are in the process of being accreted into the Milky Way. These satellite galaxies also contribute globular star clusters to the larger galaxy. The Sparkler Galaxy provides a snapshot of an infant Milky Way as it accretes mass over cosmic time. James Josephides, Swinburne University.

Read more