NASA/ESA/Leah Hustak (STScI)/Ralph Crawford (STScI)
The artist’s illustration depicts exoplanet GJ 9827d (foreground, right), the smallest exoplanet with detected water vapor in its atmosphere, orbiting its host star. His two inner planets in the system (bottom left) are also shown.
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astronomer using hubble space telescope Water molecules detected in the atmosphere of a small, scorching exoplanet97 light years From the earth.
The planet, named GJ 9827d, is about twice the diameter of Earth, making it the smallest exoplanet known to have water vapor in its atmosphere, according to a new study.
Water is essential for life as we know it, but this planet is unlikely to be habitable to any kind of life due to the scorching temperatures that turn the water-rich atmosphere into scorching steam.
Although astronomers have not yet determined the true nature of this unusual world’s atmosphere, the revelation paves the way for further research to try to understand the origins of planets outside our solar system.
The findings were published in a report released Thursday. Astrophysics Journal Letter.
“The presence of water on such a small planet is a groundbreaking discovery,” said study co-author and managing director of the Department of Exoplanet Atmospheric Physics at the Max Planck Institute for Astronomy in Heidelberg, Germany. one Laura Kreidberg said in a statement. “This brings us closer than ever to characterizing a truly Earth-like world.”
But the planet’s temperature reaches 800 degrees Fahrenheit (427 degrees Celsius), making it as hot, muggy and inhospitable as Venus.
“This is the first time that atmospheric sensing can directly show that these planets with water-rich atmospheres can actually exist around other stars,” said study co-author and researcher at the University of Montreal. said Björn Beneke, professor at the Trottier Institute. He mentioned exoplanets in his statement. “This is an important step toward determining the extent and diversity of rocky planets’ atmospheres.”
The research team is now wondering whether Hubble captured traces of water vapor in the fluffy hydrogen-rich atmosphere, or whether the planet is water-rich because its host star evaporated GJ 9827d’s original hydrogen and helium atmosphere. It is not possible to know whether there is an atmosphere.
“Our observation program, led by principal investigator Ian Crossfield at the (University of Kansas) in Lawrence, Kansas, not only detects molecules in Earth’s atmosphere, but actually specifically looks for water vapor. “It was designed to … “Whether it’s water vapor-dominant or just a small species in a hydrogen-dominant atmosphere, both results will be interesting.”
NASA’s Kepler mission first discovered a planet orbiting a red dwarf star in the constellation Pisces in 2017. This exoplanet orbits its host star once every 6.2 days.
Astronomers observed GJ 9827d’s 11 passes over three years, or the number of times the planet crosses in front of the star during its orbit. Starlight passing through the planet’s atmosphere helped astronomers measure the characteristics of water molecules.
“Until now, we have not been able to directly detect the atmospheres of such small planets, and we are now gradually entering this regime,” Beneke said. “As we study smaller planets, at some point there should be a transition where these small planets run out of hydrogen and have atmospheres similar to Venus (dominated by carbon dioxide).”
Understanding more about the planet’s atmosphere could help astronomers classify exactly what type of world GJ 9827d is. The team currently has two theories on him.
This planet could be a mini-Neptune with a hydrogen-rich atmosphere containing water vapor. If so, GJ 9827d likely formed further from its host star than its current location, meaning the planet was colder and water existed in the form of ice ( (as well as Neptune and Uranus, the most distant planets in the solar system).
As the planet moves closer to its star and is bombarded with more stellar radiation, the hydrogen heats up and escapes, or is still escaping, the researchers say.
Alternatively, astronomers suspect that GJ 9827d could be a warmer version of Jupiter’s icy moon Europa, which contains an ocean beneath its thick icy crust. Beneke said the planet could be half water and half rock.
Water is one of the most commonly found molecules throughout the universe, and astronomers have long included detecting water as a large part of the search for extraterrestrial life.
“Looking at water is a gateway to discovering other things,” study co-author Thomas Green, an astrophysicist at NASA’s Ames Research Center in Silicon Valley, California, said in a statement. “This Hubble discovery opens the door to future studies of these types of planets with the James Webb Space Telescope. By adding infrared observations, JWST will detect carbon monoxide, carbon dioxide, methane, and other We can see much more, such as carbon-containing molecules. Once we have a complete inventory of a planet’s elements, we can compare them to the star it orbits and understand how the planet formed. Become.”
Astronomers have already observed GJ 9827d with the Webb Telescope to look for water and other types of molecules, and the data will be shared in the future.
“I can’t wait to see what these data reveal,” Kreidberg said. “I hope that we can solve the problems of the water world once and for all.”