Saturn's moon Titan may not have a buried ocean as long suspected, new study suggests

CAPE CANAVERAL, Fla. (AP) — Saturn's giant moon Titan may not have a vast underground ocean after all.

Titan instead may hold deep layers of ice and slush more akin to Earth’s polar seas, with pockets of melted water where life could possibly survive and even thrive, scientists reported Wednesday.

The team led by researchers at NASA's Jet Propulsion Laboratory challenged the decade-long assumption of a buried global ocean at Titan after taking a fresh look at observations made years ago by NASA’s Cassini spacecraft around Saturn.

They stress that no one has found any signs of life at Titan, the solar system’s second largest moon spanning 3,200 miles (5,150 kilometers) and brimming with lakes of liquid methane on its frosty surface.

But with the latest findings suggesting a slushy, near-melting environment, “there is strong justification for continued optimism regarding the potential for extraterrestrial life,” said the University of Washington’s Baptiste Journaux, who took part in the study published in the journal Nature.

As to what form of life that might be, possibly strictly microscopic, “nature has repeatedly demonstrated far greater creativity than the most imaginative scientists," he said in an email.

JPL’s Flavio Petricca, the lead author, said Titan’s ocean may have frozen in the past and is currently melting, or its hydrosphere might be evolving toward complete freezing.

Computer models suggest these layers of ice, slush and water extend to a depth of more than 340 miles (550 kilometers). The outer ice shell is thought to be about 100 miles (170 kilometers) deep, covering layers of slush and pools of water that could go down another 250 miles (400 kilometers). This water could be as warm as 68 degrees Fahrenheit (20 degrees Celsius).

Because Titan is tidally locked, the same side of the moon faces Saturn all the time, just like our own moon and Earth. Saturn’s gravitational pull is so intense that it deforms the moon’s surface, creating bulges as high as 30 feet (10 meters) when the two bodies are closest.

Through improved data processing, Petricca and his team managed to measure the timing between the peak gravitational tug and the rising of Titan’s surface. If the moon held a wet ocean, the effect would be immediate, Petricca said, but a 15-hour gap was detected, indicating an interior of slushy ice with pockets of liquid water. Computer modeling of Titan’s orientation in space supported their theory.

Sapienza University of Rome’s Luciano Iess, whose previous studies using Cassini data indicated a hidden ocean at Titan, is not convinced by the latest findings.

While “certainly intriguing and will stimulate renewed discussion ... at present, the available evidence looks certainly not sufficient to exclude Titan from the family of ocean worlds," Iess said in an email.

NASA’s planned Dragonfly mission — featuring a helicopter-type craft due to launch to Titan later this decade — is expected to provide more clarity on the moon’s innards. Journaux is part of that team.

Saturn leads the solar system’s moon inventory with 274. Jupiter’s moon Ganymede is just a little larger than Titan, with a possible underground ocean. Other suspected water worlds include Saturn’s Enceladus and Jupiter’s Europa, both of which are believed to have geysers of water erupting from their frozen crusts.

Launched in 1997, Cassini reached Saturn in 2004, orbiting the ringed planet and flying past its moons until deliberately plunging through Saturn’s atmosphere in 2017.

The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education and the Robert Wood Johnson Foundation. The AP is solely responsible for all content.

FILE - This image provided by NASA shows bright methane clouds drifting in the summer skies of Saturn's moon Titan, along with dark hydrocarbon lakes and seas clustered around the north pole, as seen from the Cassini spacecraft, June 9, 2017. (NASA/JPL-Caltech/Space Science Institute via AP, File)

FILE - This image made by the Cassini spacecraft and provided by NASA on March 12, 2006, shows two of Saturn's moons, the small Epimetheus and smog-enshrouded Titan, with Saturn's A and F rings stretching across the frame. (NASA via AP)

WASHINGTON (AP) — Four centrist Republicans broke with Speaker Mike Johnson on Wednesday and signed onto a Democratic-led petition that will force a House vote on extending for three years an enhanced pandemic-era subsidy that lowers health insurance costs for millions of Americans.

The stunning move comes after House Republican leaders pushed ahead with a health care bill that does not address the soaring monthly premiums that millions of people will soon endure as the tax credits for those who buy insurance through the Affordable Care Act expire at year’s end.

Democrats led by Minority Leader Hakeem Jeffries of New York needed 218 signatures to force a floor vote on their bill, which would extend the subsides for three years.

Republican Reps. Brian Fitzpatrick, Robert Bresnahan and Ryan Mackenzie, all from Pennsylvania, and Mike Lawler of New York signed on Wednesday morning, pushing it to the magic number of 218. A vote on the subsidy bill could come as soon as January under House rules.

“Unfortunately, it is House leadership themselves that have forced this outcome.” Fitzpatrick said in a statement.

The revolt against GOP leadership came after days of talks centered on the health care subsidies.

Johnson, R-La., had discussed allowing more politically vulnerable GOP lawmakers a chance to vote on bills that would temporarily extend the subsidies while also adding changes such as income caps for beneficiaries. But after days of discussions, the leadership sided with the more conservative wing of the party's conference, which has assailed the subsidies as propping up a failed ACA marketplace.

House Republicans pushed ahead Wednesday a 100-plus-page health care package without the subsidies, instead focusing on long-sought GOP proposals designed to expand insurance coverage options for small businesses and the self-employed.

Fitzpatrick and Lawler tried to add a temporary extension of the subsidies to the bill, but were denied.

“Our only request was a floor vote on this compromise, so that the American People’s voice could be heard on this issue. That request was rejected. Then, at the request of House leadership I, along with my colleagues, filed multiple amendments, and testified at length to those amendments,” Fitzpatrick said. “House leadership then decided to reject every single one of these amendments.

“As I’ve stated many times before, the only policy that is worse than a clean three-year extension without any reforms, is a policy of complete expiration without any bridge," Fitzpatrick said.

Lawler, in a social media post, similarly said that “the failure of leadership” to permit a vote had left him with “no choice” but to sign the petition. He urged Johnson to bring the plan up for an immediate floor vote.

Speaker of the House Mike Johnson, R-La., meets with reporters as Republicans struggle with a plan to address growing health care costs, at the Capitol in Washington, Tuesday, Dec. 16, 2025. (AP Photo/J. Scott Applewhite)

FILE - Pages from the U.S. Affordable Care Act health insurance website healthcare.gov are seen on a computer screen in New York, Aug. 19, 2025. (AP Photo/Patrick Sison, File)