We've cracked riddle of ANTIGRAVITY mountains on Saturn's Titan - boffins

Underground roots of ice fingered after Cassini probe's bizarre readings


Pic An icy shell around Saturn's largest moon Titan is thicker and tougher than boffins previously thought – and it is concealing a bizarre interior with inward-facing spikes.

ESA's Huygens probe image of a mountain on the surface of Titan

A root mountaintop on Titan. Credit: ESA/NASA/JPL/University of Arizona

NASA's Cassini space probe buzzed the mysterious heavenly body in February to scan its gravity field. Now researchers, who are poring over the collected data, have theorised that the ice surrounding the moon is likely rigid, with frozen roots jutting through the underlying hidden ocean.

Sensor readings from small peaks on the landscape led planetary scientists Douglas Hemingway and Francis Nimmo from the University of California, Santa Cruz to believe that the shell has inner spikes extending into the moon's interior.

"Normally, if you fly over a mountain, you expect to see an increase in gravity due to the extra mass of the mountain," said Nimmo, a Cassini project scientist. "On Titan, when you fly over a mountain, the gravity gets lower. That's a very odd observation."

The explanation for this gravity shift could be that each mountain is actually the top of these deep roots, which are like icebergs pushing into the interior oceans. Cassini detected a weaker gravitational force because ice is slightly less dense than water (which means, in a given space, there's less mass and therefore less gravitational pull).

"It's like a big beach ball under the ice sheet pushing up on it, and the only way to keep it submerged is if the ice sheet is strong," said Cassini team associate Hemingway, who was lead author on a paper about the findings. "If large roots under the ice shell are the explanation, this means that Titan's ice shell must have a very thick rigid layer."

If the boffins are correct, that means that the tough layer is unlikely to have ice volcanoes, which other scientists have theorised could be responsible for other features on Titan.

The findings also suggest that the ice shell isn't recycled by plate tectonics or convection, like Earth's geologically active crust is. ®

Similar topics

Broader topics

Narrower topics


Other stories you might like

  • Twitter founder Dorsey beats hasty retweet from the board
    As shareholders sue the social network amid Elon Musk's takeover scramble

    Twitter has officially entered the post-Dorsey age: its founder and two-time CEO's board term expired Wednesday, marking the first time the social media company hasn't had him around in some capacity.

    Jack Dorsey announced his resignation as Twitter chief exec in November 2021, and passed the baton to Parag Agrawal while remaining on the board. Now that board term has ended, and Dorsey has stepped down as expected. Agrawal has taken Dorsey's board seat; Salesforce co-CEO Bret Taylor has assumed the role of Twitter's board chair. 

    In his resignation announcement, Dorsey – who co-founded and is CEO of Block (formerly Square) – said having founders leading the companies they created can be severely limiting for an organization and can serve as a single point of failure. "I believe it's critical a company can stand on its own, free of its founder's influence or direction," Dorsey said. He didn't respond to a request for further comment today. 

    Continue reading
  • Snowflake stock drops as some top customers cut usage
    You might say its valuation is melting away

    IPO darling Snowflake's share price took a beating in an already bearish market for tech stocks after filing weaker than expected financial guidance amid a slowdown in orders from some of its largest customers.

    For its first quarter of fiscal 2023, ended April 30, Snowflake's revenue grew 85 percent year-on-year to $422.4 million. The company made an operating loss of $188.8 million, albeit down from $205.6 million a year ago.

    Although surpassing revenue expectations, the cloud-based data warehousing business saw its valuation tumble 16 percent in extended trading on Wednesday. Its stock price dived from $133 apiece to $117 in after-hours trading, and today is cruising back at $127. That stumble arrived amid a general tech stock sell-off some observers said was overdue.

    Continue reading
  • Amazon investors nuke proposed ethics overhaul and say yes to $212m CEO pay
    Workplace safety, labor organizing, sustainability and, um, wage 'fairness' all struck down in vote

    Amazon CEO Andy Jassy's first shareholder meeting was a rousing success for Amazon leadership and Jassy's bank account. But for activist investors intent on making Amazon more open and transparent, it was nothing short of a disaster.

    While actual voting results haven't been released yet, Amazon general counsel David Zapolsky told Reuters that stock owners voted down fifteen shareholder resolutions addressing topics including workplace safety, labor organizing, sustainability, and pay fairness. Amazon's board recommended voting no on all of the proposals.

    Jassy and the board scored additional victories in the form of shareholder approval for board appointments, executive compensation and a 20-for-1 stock split. Jassy's executive compensation package, which is tied to Amazon stock price and mostly delivered as stock awards over a multi-year period, was $212 million in 2021. 

    Continue reading
  • Confirmed: Broadcom, VMware agree to $61b merger
    Unless anyone out there can make a better offer. Oh, Elon?

    Broadcom has confirmed it intends to acquire VMware in a deal that looks set to be worth $61 billion, if it goes ahead: the agreement provides for a “go-shop” provision under which the virtualization giant may solicit alternative offers.

    Rumors of the proposed merger emerged earlier this week, amid much speculation, but neither of the companies was prepared to comment on the deal before today, when it was disclosed that the boards of directors of both organizations have unanimously approved the agreement.

    Michael Dell and Silver Lake investors, which own just over half of the outstanding shares in VMware between both, have apparently signed support agreements to vote in favor of the transaction, so long as the VMware board continues to recommend the proposed transaction with chip designer Broadcom.

    Continue reading
  • Perl Steering Council lays out a backwards compatible future for Perl 7
    Sensibly written code only, please. Plus: what all those 'heated discussions' were about

    The much-anticipated Perl 7 continues to twinkle in the distance although the final release of 5.36.0 is "just around the corner", according to the Perl Steering Council.

    Well into its fourth decade, the fortunes of Perl have ebbed and flowed over the years. Things came to a head last year, with the departure of former "pumpking" Sawyer X, following what he described as community "hostility."

    Part of the issue stemmed from the planned version 7 release, a key element of which, according to a post by the steering council "was to significantly reduce the boilerplate needed at the top of your code, by enabling a lot of widely used modules / pragmas."

    Continue reading

Biting the hand that feeds IT © 1998–2022