24/7 Space News
Researchers measure the light emitted by a sub-Neptune planet's atmosphere for the first time
Typical sub-Neptune as theorized.
Researchers measure the light emitted by a sub-Neptune planet's atmosphere for the first time
by Staff Writers
College Park MD (SPX) May 11, 2023

For more than a decade, astronomers have been trying to get a closer look at GJ 1214b, an exoplanet 40 light-years away from Earth. Their biggest obstacle is a thick layer of haze that blankets the planet, shielding it from the probing eyes of space telescopes and stymying efforts to study its atmosphere.

NASA's new James Webb Space Telescope (JWST) solved that issue. The telescope's infrared technology allows it to see planetary objects and features that were previously obscured by hazes, clouds or space dust, aiding astronomers in their search for habitable planets and early galaxies.

A team of researchers used JWST to observe GJ 1214b's atmosphere by measuring the heat it emits while orbiting its host star. Their results, published in the journal Nature on May 10, 2023, represent the first time anyone has directly detected the light emitted by a sub-Neptune exoplanet-a category of planets that are larger than Earth but smaller than Neptune.

Though GJ 1214b is far too hot to be habitable, researchers discovered that its atmosphere likely contains water vapor-possibly even significant amounts-and is primarily composed of molecules heavier than hydrogen. University of Maryland Associate Professor of Astronomy Eliza Kempton, lead author of the Nature study, said their findings mark a turning point in the study of sub-Neptune planets like GJ 1214b.

"I've been on a quest to understand GJ 1214b for more than a decade," Kempton said. "When we received the data for this Nature paper, we could see the light from the planet just disappear when it went behind its host star. That had never before been seen for this planet or for any other planet of its class, so JWST is really delivering on its promise."

A 'new light'
Sub-Neptunes are the most common type of planet in the Milky Way, though none exist in our solar system. Despite the murkiness of GJ 1214b's atmosphere, Kempton and her co-authors determined the planet was still their best chance of observing a sub-Neptune's atmosphere because of its bright but small host star.

In their Nature paper, the researchers measured the infrared light that GJ 1214b emitted over the course of about 40 hours-the time it takes the planet to orbit its star. As day turns to night, the amount of heat that shifts from one side of a planet to the other depends largely on what its atmosphere is made of. Known as a phase curve observation, this research method opened a new window into the planet's atmosphere.

"JWST operates at longer wavelengths of light than previous observatories, which gives us access to the heat emitted by the planet and allows us to create a map of the planet's temperature," Kempton said. "We finally got to see GJ 1214b in a new light."

By measuring the movement and fluctuation of heat, the researchers determined that GJ 1214b does not have an atmosphere dominated by hydrogen.

Potential water world?
The question of whether GJ 1214b contains water has long interested astronomers. Previous observations by NASA's Hubble Space Telescope suggested that GJ 1214b could be a water world-a loose term for any planet that contains a significant amount of water.

The latest JWST data revealed traces of water, methane or some mix of the two. These substances match a subtle absorption of light seen in the wavelength range observed by JWST. Further studies will be needed to determine the exact makeup of the planet's atmosphere, but Kempton said the evidence remains consistent with the possibility of large amounts of water.

"GJ 1214b, based on our observations, could be a water world," Kempton said. "We think we detect water vapor, but it's challenging because water vapor absorption overlaps with methane absorption, so we can't say 100% that we detected water vapor and not methane. However, we see this evidence on both hemispheres of the planet, which heightens our confidence that there really is water there."

Reflecting on the findings
The researchers made another surprising discovery in their study: GJ 1214b is incredibly reflective. The planet was not as hot as expected, which tells researchers that something in the atmosphere is reflecting light.

Kempton said there is plenty of room for follow-up studies, including ones that take a closer look at the high-altitude aerosols that form the haze-or possibly clouds-in GJ 1214b's atmosphere. Previously, researchers thought it might be a dark, soot-like substance that absorbs light. However, the discovery that the exoplanet is reflective raises new questions.

"Whatever is making up the hazes or clouds is not what we expected. It's bright, it's reflective and that's confusing and surprising," Kempton said. "This is going to point us toward a lot of further studies to try to understand what those hazes could be."

Research Report:A reflective, metal-rich atmosphere for GJ 1214b from its JWST phase curve

Related Links
University of Maryland
Lands Beyond Beyond - extra solar planets - news and science
Life Beyond Earth

Subscribe Free To Our Daily Newsletters

The following news reports may link to other Space Media Network websites.
Webb looks for Fomalhaut's asteroid belt and finds much more
Baltimore MD (SPX) May 09, 2023
The belts encircle the young hot star, which can be seen with the naked eye as the brightest star in the southern constellation Piscis Austrinus. The dusty belts are the debris from collisions of larger bodies, analogous to asteroids and comets, and are frequently described as 'debris disks.' "I would describe Fomalhaut as the archetype of debris disks found elsewhere in our galaxy, because it has components similar to those we have in our own planetary system," said Andras Gaspar of the University of A ... read more

Cosmonauts wrap up 5-hour ISS spacewalk

SpaceX set to launch Vast's commercial space station and inaugural human spaceflight mission

NASA launches SBIR Ignite Catalyst Program for founders and entrepreneurs

Virgin to launch commercial spaceflights in June

Virgin Orbit receives more than 30 indications of interest under court approved bid procedures

Wenchang Spacecraft Launch Site can launch new-generation rockets

For 191st time, SpaceX booster successfully returns after launch

Momentus signs launch package with SpaceX

These sounds are out of this world

Chasms on the flanks of a Martian volcano

Another beautiful hole on Mars: Sols 3825-3826

Perseverance images may show record of wild Martian river

China's cargo craft Tianzhou 6 ready for launch

"Tianzhou Express" is online again, with five highlights

Tianzhou 6 docks with Tiangong space station

Tianzhou-5 cargo craft separates from China's space station

SpaceX launches 51 Starlink satellites from California

Sidus Space selected by OneWeb to manufacture satellite hardware

Sidus Space expands global ground site network with new ATLAS contract

Lockheed Martin Space announces changes designed to enhance speed and effectiveness

Great balls of fire! 'Rocket debris' lights up Japan night

Arianespace to launch the first active debris removal ClearSpace mission with Vega C

Juice's RIME antenna breaks free

Terran Orbital PTD-3 enables 200Gbits space-to-ground optical link

Researchers measure the light emitted by a sub-Neptune planet's atmosphere for the first time

Bacteria survive on radioactive elements

Webb takes closest look yet at mysterious planet

Astronomers spot benzene in planet-forming disk around star for first time

Pioneer 11, launched 50 years ago, helped solve mysteries of the universe

NASA: Up to 4 of Uranus' moons could have water

New video series captures team working on NASA's Europa Clipper

Work continues to deploy Juice RIME antenna

Subscribe Free To Our Daily Newsletters


The content herein, unless otherwise known to be public domain, are Copyright 1995-2023 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.