dima_zel/Getty Images
- Scientists say they observed a planet that may have an ocean-covered surface, the Guardian reported.
- The observations were made using NASA's James Webb space telescope.
- But a Canadian research group said the planet is likely too hot for liquid water.
Researchers say they have observed a Neptune-like planet that could be covered by a deep-water ocean, the Guardian reported.
A team from the University of Cambridge in the UK said it had found evidence of water vapor and chemical signatures of carbon dioxide and methane on an exoplanet known as TOI-270 d, which is around 70 light years away.
The team used NASA's James Webb space telescope to make observations of the planet, which has twice the radius of Earth and a mass of 4.78 Earths, per NASA.
Nikku Madhusudhan, a professor of astrophysics at the University of Cambridge who led the research, told the Guardian, "the ocean could be upwards of 100 degrees [Celsius] or more," adding that with high atmospheric pressure, that ocean could still be liquid.
But it was "not clear if it would be habitable," he said.
The planet is also tidally locked, meaning one side is left in constant darkness while the other faces its star, per the report.
"The ocean would be extremely hot on the day side. The night side could potentially host habitable conditions," Madhusudhan added.
A liquid ocean is the preferred premise set out in a paper published in the journal Astronomy & Astrophysics.
The paper also notes the lack of ammonia on TOI-270 d, which it said was "consistent with predictions for a Hycean world with a planet-wide ocean" under a hydrogen-rich atmosphere.
However, a group of Canadian researchers who also observed TOI-270 d have disputed the Cambridge team's claims.
While they detected the same chemicals in the planet's atmosphere, one of the researchers told the Guardian that they believed the temperature was "too warm for water to be liquid."
Université de Montréal Professor Björn Benneke said that surface temperatures on the exoplanet could be around 4,000 degrees Celsius, or around 7,200 degrees Fahrenheit.
He added that this meant any water would be in a supercritical state, where "it's almost like a thick, hot fluid."
NASA, ESA, CSA, STScI, Tea Temim (Princeton University)
The James Webb telescope has played a key role in advancing the search for habitable planets beyond Earth.
The telescope intercepts infrared light and directs it to scientific instruments where it can be recorded.
One of its main uses is to study the atmospheres of exoplanets to see whether they could support life.
One key that scientists look for in a potentially habitable planet is the presence of liquid water.
The area around a star where water can exist in a liquid state is called the "habitable zone" or "Goldilocks' zone." Planets in this zone are neither too hot nor too cold to support liquid water.