A boiling Saturn-like planet 700 light-years from the sun has become the best-studied planet outside our solar system. Measurements of the planet’s atmosphere by the James Webb Space Telescope have revealed unprecedented details of its chemistry and even allowed astronomers to test methods for detecting extraterrestrial life.
The exoplanet WASP-39b, which orbits a star in the constellation Virgo, made headlines in late August when the James Webb Space Telescope (Webb of JWST) found carbon dioxide in its atmosphere. It was the very first such detection and experts hailed the finding as a major breakthrough. Now, less than three months later, an avalanche of studies based on the large telescope’s observations has revealed the finest details of WASP-39b’s atmosphere, even allowing astronomers to draw conclusions about the exoplanet’s formation history.
“These early observations are a harbinger of even more amazing science to come with JWST,” Laura Kreidberg, director of the Max Planck Institute for Astronomy (MPIA) in Germany, who was involved in the observations, said in a statement. pronunciation. “We put the telescope through its paces to test its performance, and it was almost flawless – even better than we hoped.”
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Astronomers used three of Webb’s four instruments to observe the distant planet: the main one NIRCam camera and the two spectroscopes NIRISS and NIRSpecwhich split light from the observed objects into light spectrathe barcode-like fingerprints that reveal the chemical composition of the observed planets and stars.
The observations revealed that WASP-39b is shrouded in thick clouds containing sulfur and silicates. These chemicals interact with the light from the parent star and produce sulfur dioxide in a reaction similar to that in which ozone is produced the Earth’s atmosphere.
WASP-39b is one gas giant about one-third the size of the solar systemlargest planet, Jupiterand orbits just 4.3 million miles (7 million kilometers) away from its parent star, or eight times closer than the distance of the solar system’s innermost planet Mercury of the sun.
The sheer intensity of starlight striking WASP-39b makes the planet an ideal laboratory for studying such photochemical reactions, scientists said in the statement.
JWST’s level of detail allowed astronomers to peek into WASP-39b’s past and learn how this hot and scorching world came to be. From the ratios of carbon to oxygen, potassium to oxygen, and sulfur to hydrogen in the planet’s atmosphere, the researchers deduced that the gas giant planet must have been formed by collisions of several smaller planetesimals. In addition, the much higher amount of oxygen compared to carbon in the thick clouds revealed that WASP-39b formed much farther from its star than it is now orbiting.
“Data like this is a game changer,” Natalia Batalha, a professor of astronomy and astrophysics at the University of California at Santa Cruz who coordinated the observation program, said in the statement.
The observations even allowed astronomers to test methods that could one day help detect life on other exoplanets. That detection would rely on a similar atmospheric analysis to that performed on WASP-39b, then compare the results with models of alien planets. For example, if the planet shows more oxygen than those models predict, that could be a sign of life.
However, due to its proximity to its parent star, WASP-39b is an unlikely candidate to host extraterrestrial life, as the planet’s temperature rises to an unlivable 1,650 degrees Fahrenheit (900 degrees Celsius).
Five new studies (1,2,3,4,5) based on JWST data are reviewed or published in the journal Nature.