A boiling Saturn-like planet 700 light-years from the sun has become the best-explored planet outside our solar system. Measurements of the planet’s atmosphere by the James Webb Space Telescope have revealed unprecedented details about its chemistry and even allowed astronomers to test methods of 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 or JWST) found carbon dioxide in its atmosphere. It was the very first detection of this type and experts hailed the discovery as a major breakthrough. Now, less than three months later, a flurry of studies based on observations from the Large Telescope have revealed the finest details of WASP-39b’s atmosphere, allowing astronomers to even draw conclusions about the story. of the formation of the exoplanet.
“These early observations are a harbinger of more amazing science to come with the JWST,” said Laura Kreidberg, director of the Max Planck Institute for Astronomy (MPIA) in Germany, which took part in the observations. statement. “We put the telescope through its paces to test performance, and it was nearly perfect – even better than we expected.”
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Astronomers used three of Webb’s four instruments to observe the distant planet: the main NIRCam camera and the two NIRISS spectroscopes and NIR specwhich split the light of observed objects into light spectrabarcode-like fingerprints that reveal the chemical compositions of observed planets and stars.
Observations revealed that WASP-39b is shrouded in thick clouds containing sulfur and silicates. These chemicals interact with light from the parent star, producing sulfur dioxide in a reaction similar to that which produces ozone in earth’s atmosphere.
WASP-39b is a The gas giant about one-third the size of the solar systemthe largest planet, Jupiterand orbits just 4.3 million miles (7 million kilometers) from its parent star, eight times closer than the distance to the innermost planet in the solar system Mercury of the sun.
The intensity of starlight striking WASP-39b makes the planet an ideal laboratory to study such photochemical reactions, the scientists said in the statement.
The level of detail provided by JWST allowed astronomers to peek into WASP-39b’s past and learn how this hot, scorching world came into existence. Based on the carbon/oxygen, potassium/oxygen and sulfur/hydrogen ratios in the planet’s atmosphere, the researchers deduced that the gas giant planet must have formed from collisions of several smaller planetesimals. Additionally, the much higher abundance of oxygen relative to carbon in the thick clouds revealed that WASP-39b formed much farther from its star than it orbits today.
“Data like this is a game-changer,” Natalia Batalha, a professor of astronomy and astrophysics at the University of California, Santa Cruz, who coordinated the observing program, said in the statement.
The observations have even allowed astronomers to test methods that could one day help detect life on other exoplanets. This detection would be based on an atmospheric analysis similar to that carried out on WASP-39b, then compare the results with models of extraterrestrial planets. If the planet is showing more oxygen than these models predict, for example, it could be a sign of life.
However, WASP-39b, due to its proximity to its parent star, is an unlikely candidate for hosting extraterrestrial life as the temperature on the planet soars to 1,650 degrees Fahrenheit (900 degrees Celsius).
Five new studies (1,2,3,4,5) based on JWST data are under review or in press with the journal Nature.
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