Study: New Evidence Suggests Earth-like Exoplanet May Hold Liquid Ocean
2024-07-29
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1Researchers say new telescope observations suggest an Earth-like planet outside our solar system may hold a large liquid ocean.
2The exoplanet is known as LHS 1140 b. Astronomers believe it sits about 48 light years away from Earth.
3A light year is the distance light travels in a year - about 9.5 trillion kilometers.
4The research - led by astronomers at the University of Montreal in Canada - shows the possibility the exoplanet might hold the right conditions to support some form of life.
5A study explaining the findings recently appeared in The Astrophysical Journal Letters.
6The study is based on observations collected in December 2023 by the James Webb Space Telescope.
7The American space agency NASA operates the orbiting observatory.
8Researchers combined the information from the James Webb with existing data to make new estimates for the exoplanet's mass and size.
9These suggest that LHS 1140 b is "a promising super-Earth ice or water world," the University of Montreal said in a statement.
10Some past studies had suggested the exoplanet might be a gas giant, also known as a mini-Neptune.
11But the researchers said the new study provides evidence that LHS 1140 b is more likely a super-Earth, a rocky planet bigger than Earth.
12The new research supports a NASA-led study from October 2023 that suggested at least 17 observed exoplanets could hold oceans of liquid water.
13That study noted that sometimes water from these oceans likely breaks through large pieces of ice to form geysers.
14Scientists had already identified LHS 1140 b as being within its star's "habitable zone."
15Exoplanets found within this zone are believed to have temperatures that would permit water to exist in liquid form.
16Measurements made by the James Webb data suggest the exoplanet "is less dense" than expected for a rocky, Earth-like body.
17The researchers estimated that 10 to 20 percent of LHS 1140 b's mass might be made up of water.
18The possibility of a large liquid ocean would be found on the side of the planet always facing the star that it orbits.
19The new data collected by the James Webb showed the exoplanet might also have a nitrogen-rich atmosphere.
20This differs from earlier research that suggested a possible atmosphere that was mostly hydrogen.
21Charles Cadieux is a doctoral student at the University of Montreal's Trottier Institute for Research on Exoplanets.
22He was the lead writer of the study.
23Cadieux said in a statement, "Of all currently known temperate exoplanets, LHS 1140 b could well be our best bet to one day indirectly confirm liquid water on the surface of an alien world beyond our solar system."
24He noted that if the study's findings can be confirmed, the data would represent "a major milestone" in the search for exoplanets that could possibly support life.
25René Doyon is a project scientist at the University of Montreal.
26He helped lead the research. He said more observations will be needed to confirm the current study's findings.
27"The current hint of a nitrogen-rich atmosphere begs for confirmation with more data," Doyon said.
28He estimated that at least one more year of observations will be needed "to confirm that LHS 1140 b has an atmosphere."
29The process of confirming whether carbon dioxide is present in the atmosphere and liquid water exists on the surface would likely require several years of observations, Doyon noted.
30Ryan MacDonald is a NASA Sagan Fellow in the University of Michigan's Department of Astronomy who helped examine the James Webb data.
31He said, "This is the first time we have ever seen a hint of an atmosphere on a habitable zone rocky or ice-rich exoplanet."
32With further data collection and investigation, MacDonald noted there is a good possibility "we might just have found evidence of air on this world."
33I'm Bryan Lynn.