May 2, 2024

Webb’s Cosmic Coup: Sniffing Out Methane on a Distant World

An artists making of the warm exoplanet WASP-80 b whose color may appear bluish to human eyes due to the lack of high-altitude clouds and the existence of climatic methane recognized by NASAs James Webb Space Telescope, comparable to the worlds Uranus and Neptune in our own solar system. Credit: NASA
NASAs James Webb Space Telescope has discovered methane in the environment of the exoplanet WASP-80 b, a milestone in area expedition. This discovery, validated through advanced light analysis approaches, clarifies the worlds development and enables contrasts with planets in our solar system.
NASAs James Webb Space Telescope observed the exoplanet WASP-80 b as it passed in front of and behind its host star, revealing spectra indicative of an atmosphere consisting of methane gas and water vapor. While water vapor has actually been spotted in over a dozen planets to date, until recently methane– a particle found in abundance in the environments of Jupiter, Saturn, Uranus, and Neptune within our solar system– has stayed elusive in the environments of transiting exoplanets when studied with space-based spectroscopy.
Taylor Bell from the Bay Area Environmental Research Institute (BAERI), operating at NASAs Ames Research Center in Californias Silicon Valley, and Luis Welbanks from Arizona State University tell us more about the significance of discovering methane in exoplanet environments and talk about how Webb observations facilitated the identification of this long-sought-after molecule. These findings were just recently released in the scientific journal Nature.

Taylor Bell is a postdoctoral research scientist at the Bay Area Environmental Research Institute (BAERI), working at NASAs Ames Research Center in Californias Silicon Valley.
Luis Welbanks is a NASA Hubble Fellow at Arizona State University in Tempe, Arizona.

Comprehending Warm Jupiter WASP-80 b.
” With a temperature level of about 825 kelvins (about 1,025 degrees Fahrenheit), WASP-80 b is what scientists call a “warm Jupiter,” which are planets that are similar in size and mass to the world Jupiter in our solar system but have a temperature level thats in-between that of hot Jupiters, like the 1,450 K (2,150 ° F) HD 209458 b (the very first transiting exoplanet found), and cold Jupiters, like our own which is about 125 K (235 ° F). When every 3 days and is located 163 light-years away from us in the constellation Aquila, wasp-80 b goes around its red dwarf star. We cant see the world directly with even the most advanced telescopes like Webb since the planet is so close to its star and both are so far away from us. Instead, scientists study the combined light from the star and world using the transit approach (which has actually been utilized to discover most recognized exoplanets), and the eclipse method.
Innovative Observational Techniques.
Using the transit technique, we observed the system when the planet moved in front of its star from our point of view, causing the starlight we see to dim a bit. When somebody passes in front of a light and the light dims, its kind of like. Throughout this time, a thin ring of the planets atmosphere around the worlds day/night boundary is lit up by the star, and at particular colors of light where the molecules in the planets atmosphere soak up light, the environment looks thicker and obstructs more starlight, triggering a much deeper dimming compared to other wavelengths where the atmosphere appears transparent. This approach helps scientists like us comprehend what the planets atmosphere is made of by seeing which colors of light are being obstructed.
Simply before and after the eclipse, the planets hot dayside is pointed towards us, and by determining the dip in light throughout the eclipse we were able to determine the infrared light given off by the world. For eclipse spectra, absorption by particles in the worlds environment usually appear as a reduction in the planets emitted light at specific wavelengths.
Throughout a transit, the world passes in front of the star, and in a transit spectrum, the presence of particles makes the worlds atmosphere block more light at specific colors, causing a deeper dimming at those wavelengths. During an eclipse, the planet passes behind the star, and in this eclipse spectrum, molecules absorb some of the planets given off light at specific colors, leading to a smaller dip in brightness during the eclipse compared to a transit.
Examining Spectral Data.
The preliminary observations we made needed to be transformed into something we call a spectrum; this is essentially a measurement revealing how much light is either obstructed or emitted by the planets environment at different colors (or wavelengths) of light. Next, we translated this spectrum using 2 kinds of designs to imitate what the environment of a world under such extreme conditions would look like. The 2nd type, called self-consistent designs, also explores millions of mixes however utilizes our existing knowledge of physics and chemistry to determine the levels of methane and water that might be expected.
To verify our findings, we utilized robust analytical techniques to examine the likelihood of our detection being random noise. In our field, we relate to the gold requirement to be something called a 5-sigma detection, indicating the odds of a detection being triggered by random sound are 1 in 1.7 million. On the other hand, we found methane at 6.1-sigma in both the transit and eclipse spectra, which sets the odds of a spurious detection in each observation at 1 in 942 million, exceeding the 5-sigma gold standard, and reinforcing our self-confidence in both detections.
Ramifications of Methane Detection.
With such a positive detection, not only did we discover a very evasive molecule, however we can now start exploring what this chemical structure informs us about the worlds development, birth, and evolution. For instance, by determining the amount of methane and water in the planet, we can infer the ratio of carbon atoms to oxygen atoms. This ratio is anticipated to alter depending upon where and when planets form in their system. Thus, analyzing this carbon-to-oxygen ratio can use ideas regarding whether the world formed near to its star or farther away before slowly moving inward.
Another thing that has us thrilled about this discovery is the chance to finally compare worlds beyond our solar system to those in it. NASA has a history of sending out spacecraft to the gas giants in our solar system to measure the quantity of methane and other particles in their environments. Now, by having a measurement of the very same gas in an exoplanet, we can start to perform an “apples-to-apples” contrast and see if the expectations from the solar system match what we see beyond it.
Future Prospects With the James Webb Space Telescope.
Lastly, as we look towards future discoveries with Webb, this outcome shows us that we are at the brink of more amazing findings. Additional MIRI and NIRCam observations of WASP-80 b with Webb will permit us to penetrate the homes of the atmosphere at different wavelengths of light. Our findings lead us to think that we will have the ability to observe other carbon-rich particles such as carbon monoxide gas and carbon dioxide, enabling us to paint a more comprehensive image of the conditions in this planets environment.
Additionally, as we find methane and other gases in exoplanets, we will continue to expand our knowledge about how chemistry and physics works under conditions unlike what we have on Earth, and perhaps at some point soon, in other worlds that remind us of what we have here in the house. Something is clear– the journey of discovery with the James Webb Space Telescope is brimming with possible surprises.”.
Referral: “Methane throughout the environment of the warm exoplanet WASP-80b” by Taylor J. Bell, Luis Welbanks, Everett Schlawin, Michael R. Line, Jonathan J. Fortney, Thomas P. Greene, Kazumasa Ohno, Vivien Parmentier, Emily Rauscher, Thomas G. Beatty, Sagnick Mukherjee, Lindsey S. Wiser, Martha L. Boyer, Marcia J. Rieke and John A. Stansberry, 22 November 2023, Nature.DOI: 10.1038/ s41586-023-06687-0.
About the authors:.

Throughout this time, a thin ring of the worlds atmosphere around the planets day/night limit is lit up by the star, and at specific colors of light where the molecules in the worlds environment take in light, the environment looks thicker and blocks more starlight, triggering a deeper dimming compared to other wavelengths where the environment appears transparent. Simply before and after the eclipse, the worlds hot dayside is pointed towards us, and by measuring the dip in light throughout the eclipse we were able to measure the infrared light produced by the planet. For eclipse spectra, absorption by molecules in the worlds environment normally appear as a decrease in the planets released light at particular wavelengths. During a transit, the planet passes in front of the star, and in a transit spectrum, the presence of particles makes the worlds atmosphere block more light at particular colors, causing a much deeper dimming at those wavelengths. Throughout an eclipse, the world passes behind the star, and in this eclipse spectrum, particles soak up some of the planets given off light at particular colors, leading to a smaller dip in brightness during the eclipse compared to a transit.