Steamy world could be a sample of water-rich planets across the galaxy
The search for life in space runs parallel to the search for water on planets around other stars. Water is one of the most common molecules in the universe, and all life on Earth requires it. Water acts as a solvent by dissolving substances and enabling important chemical reactions within the cells of animals, plants, and microorganisms. It is much better than other liquids in this respect.
Astronomers are intrigued when they find evidence of water vapor on exoplanets. The latest target is the planet GJ 9827d, which may have a water-rich atmosphere around it. This planet, which is less than twice that of Earth’s in diameter, could be an example of a water-rich world that may exist elsewhere in the galaxy. However, I have no intention of purchasing property in GJ 9827d.Earth is just as hot Venusat 800 degrees Fahrenheit. This makes for a steamy world.
Hubble Space Telescope discovers water vapor in the atmosphere of a small exoplanet
Astronomers using NASA’s Hubble Space Telescope have observed the smallest exoplanet with water vapor detected in its atmosphere. Planet GJ 9827d, which is only about twice the diameter of Earth, could be an example of a planet elsewhere in the galaxy that could have a water-rich atmosphere.
“Atmospheric sensing directly shows that these planets with water-rich atmospheres can indeed exist around other stars,” said Bjorn Beneke, a team member at the Trottier Institute for Exoplanet Research at the University of Montreal. This is the first time I’ve been able to do that.” . “This is an important step toward determining the extent and diversity of rocky planets’ atmospheres.”
“The presence of water on such a small planet is a groundbreaking discovery,” added co-principal investigator Laura Kreidberg of the Max Planck Institute for Astronomy in Heidelberg, Germany. “This brings us closer than ever to characterizing a truly Earth-like world.”
Investigate a planet’s atmosphere
But whether Hubble used spectroscopy to measure small amounts of water vapor in the hydrogen-rich bulging atmosphere, or whether the planet’s atmosphere was made mostly of water and the primordial hydrogen/helium atmosphere was exposed to star radiation It is too early to tell whether this is what remains after evaporation. .
“Our observation program, led by Principal Investigator Ian Crossfield of the University of Kansas in Lawrence, Kansas, is specifically designed to not only detect molecules in Earth’s atmosphere, but actually specifically look for water vapor. Whether water vapor is dominant or only a small amount of water vapor, either result would be interesting. seed in a hydrogen-dominated atmosphere,” said Pierre-Alexis Roy, lead author of the scientific paper from the University of Montreal’s Trottier Institute for Exoplanet Research.
“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 added. “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).”
At 800 degrees Fahrenheit, this planet is as hot as Venus, so if the atmosphere was primarily water vapor, it would definitely be a stuffy, inhospitable world.
Implications and future research
At the moment, the team has two possibilities left. One scenario is that the planet is still attached to a hydrogen-rich atmosphere mixed with water, making it a mini-planet.Neptune. Or it could be a warmer version. JupiterThe moon Europa has twice as much water under its crust as Earth. “Planet GJ 9827d could be half water, half rock. And there would be a lot of water vapor on top of the small rocky object,” Beneke said.
If a planet still has a water-rich atmosphere, it must have formed farther away from its host star, where temperatures are cooler than its current location and water is available in the form of ice. In this scenario, the planet would be closer to the star and receive more radiation. The hydrogen has either heated up and escaped, or is still trying to escape Earth’s weak gravity. Another theory is that the planet formed near a hot star and had trace amounts of water in its atmosphere.
The Hubble mission observed the planet during 11 transits (events in which a planet passes in front of its star) over three years apart. During its passage, the star’s light is filtered through the planet’s atmosphere, carrying a spectral fingerprint of water molecules. If there are clouds on Earth, they are low enough in the atmosphere that Hubble’s view of the atmosphere is not completely obscured, and Hubble can study the water vapor above the clouds.
“Looking at water is a gateway to discovering other things,” says astrophysicist Thomas Green. NASAAmes Research Center in California’s Silicon Valley. “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.”
GJ 9827d was discovered by NASA’s Kepler Space Telescope in 2017. GJ 9827d orbits the red dwarf every 6.2 days. The star GJ 9827 is located 97 light years from Earth in the constellation Pisces.
Reference: “Water absorption in the transmission spectrum of the water world candidate GJ 9827 d” Pierre-Alexis Roy, Björn Benneke, Caroline Piaulet, Michael A. Gully-Santiago, Ian JM Crossfield, Caroline V. Morley, Laura Kreidberg, Thomas Written by Mikal Evans, Jonathan Brand, Simon Delisle, Thomas P. Green, Kevin K. Hardigley-Ullman, Travis Berman, Jesse L. Christiansen, Diana Dragomir, Jonathan J. Fortney, Andrew W. Howard, Molly R. Kosiarek, Joshua D. Roslinger, September 12, 2023, of Astrophysics Journal Letter.
DOI: 10.3847/2041-8213/acebf0
of hubble space telescope This is an international cooperation project between NASA and ESA. NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts science operations for Hubble and Webb. STScI is operated for NASA by the Association of Universities for Astronomical Research in Washington, DC.