Year: 2024

Scientists: We think the Saturn moon Mimas may have a young underground ocean

8:45 am

The uncertainty of science: Using computer modeling based on orbital data obtained from the orbiter Cassini, scientist now believe the Saturn moon Mimas may have a young underground ocean.

[I]n 2014, a team that included Lainey and that was led by Radwan Tajeddine, an astronomer then at the Paris Observatory, analysed images taken by NASA’s Cassini spacecraft, which explored Saturn and its moons between 2004 and 2017. By studying how the 400-kilometre-wide Mimas wobbled in its orbit around Saturn, the researchers concluded that it had either a buried ocean or a rugby-ball-shaped core. As more scientists studied how an ocean could have formed and evolved, it became harder to explain the geology of Mimas without invoking an ocean.

In the 2024 study, Lainey and his colleagues seem to have nailed the case. They went further than they had in 2014, by analysing not just the orbit’s wobble but also how Mimas’s rotation around Saturn changed over time. The team combined Cassini observations with simulations of Mimas’s interior and its orbit to conclude that there must be an ocean 20–30 kilometres below Mimas’s surface.

The journal Nature published the paper, and the link above goes to an article in Nature describing the results, with a headline “The Solar System has a new ocean — it’s buried in a small Saturn moon.” This is very poor journalism, but very typical these days from Nature. Nowadays that journal routinely pushes the results it publishes with great certainty, even if the data is quite uncertain.

And these results are quite uncertain. They are based on computer simulations using orbital data only. No data from Mimas itself is involved. While that orbital data and computer models might suggest an underground ocean that is very young, that is the best it does, “suggest.” Without question this conclusion is very intriguing, but it should not be treated as a discovery, only a theory that still needs confirmation with much better data.

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February 7, 2024 Quick space links

3:29 pm

Courtesy of BtB’s stringer Jay. This post is also an open thread. I welcome my readers to post any comments or additional links relating to any space issues, even if unrelated to the links below.

 

 

 

 

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Pushback: Fired by Disney for noting Nazis killed Jews, actress sues, her lawyers paid for by X

2:24 pm

Gina Carano's tweet about the Nazi genocide

Bring a gun to a knife fight: Back in February 2021 my daily blacklist column focused on the horrible blackballing of actress Gina Carano by the Disney corporation. It had fired her because of the tweet to the right, in which she had stated some undeniable facts about the Nazis and their compaign to murder the Jews. As a company spokesperson stated falsely at her firing,

[H]er social media posts denigrating people based on their cultural and religious identities are abhorrent and unacceptable.

It was the company’s false and slanderous position — as demonstrated by numerous other actions at the same time — that Carano’s conservative positions on many issues was the equivalent of “denigrating” the queer and black communities, like a Nazi. To Disney, her effort to retell the history of the Holocaust in order to prevent it from happening again was unacceptable, and so it fired her.

Carano is now suing Disney and Lucasfilms for that firing and its subsequent smear campaign against her. You can read her complaint here. It is easy reading, and outlines in great detail the very reasonable positions taken by Carano in public, and the campaign of slanders against her that followed from Disney officials as well as advocates in the BLM and queer communities. Repeatedly Carano made it clear she was not attacking any particular group, and that her goal was to outline actual facts and defend the free speech rights of everyone. The response from Disney and the activists in the BLM and queer communities were slanders, lies, and falsehoods. Her case is strong, as she is suing under California law, which states that
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A small Martian volcano?

12:35 pm

A small Martian volcano?
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on December 21, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). The science team labeled it a “fresh crater”, but that description I think is misleading, as it implies a recent impact.

The crater does not look like a fresh impact crater to me. Such things on Mars usually appear very dark, as the impact dredges up dark material. This crater is not dark. More significant is the crater itself. The small 300-foot-wide inner crater, surrounded by a circular plateau and all sitting inside the larger 1,200-foot-wide crater is completely unique compared to any impact crater I have ever seen. Impacts in soft material, such as ice-impregnated ground, can cause concentric ripple rings, but they don’t look like this.

Instead, this crater more resembles the caldera of a volcano, where subsequent eruptions can produce overlapping depressions at the volcano peak. (See for example this picture of Olympus Mons.)

Moreover, the crater sits on top of a peak approximately 300 feet high. While impacts in ice-impregnated ground on Mars can produce splash aprons as seen here, the crater usually sits at about the same elevation as the surrounding terrain, not at the top of a peak. This peak suggests the apron was forned not by a splash but repeated flows coming down from the top.
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Freedom capsule undocks from ISS with AX-3 commercial crew

10:06 am

SpaceX’s Freedom capsule today undocked from ISS at 9:20 am (Eastern), carrying three European passengers and one commander, with a planned splashdown in the Atlantic off the coast of Florida at 8:30 am (Eastern) on February 9, 2024.

Ax-3 astronauts Michael López-Alegría, Walter Villadei, Marcus Wandt, and Alper Gezeravci will complete 18 days aboard the orbiting laboratory at the conclusion of their mission. The SpaceX Dragon will return to Earth with more than 550 pounds of science and supplies, including NASA experiments and hardware.

Live stream for that splashdown can be found here. The mission is a private one. Axiom sold the tickets, and purchased from SpaceX the Falcon 9 launch and use of its Freedom capsule. It also rented time on ISS from NASA for its crew and passengers.

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Computer problem on Voyager-1 remains unsolved

9:54 am

Engineers remain baffled over a computer issue that has prevented the receipt of any data since November 2023 from Voyager-1, floating some 15 billion miles away just outside the solar system in interstellar space.

In November, the data packages transmitted by Voyager 1 manifested a repeating pattern of ones and zeros as if it were stuck, according to NASA. Dodd said engineers at JPL have spent the better part of three months trying to diagnose the cause of the problem. She said the engineering team is “99.9 percent sure” the problem originated in the FDS [Flight Data Subsystem], which appears to be having trouble “frame syncing” data.

So far, the ground team believes the most likely explanation for the problem is a bit of corrupted memory in the FDS. However, because of the computer hangup, engineers lack detailed data from Voyager 1 that might lead them to the root of the issue. “It’s likely somewhere in the FDS memory,” Dodd said. “A bit got flipped or corrupted. But without the telemetry, we can’t see where that FDS memory corruption is.”

Since November the only signal received from Voyager-1 is a carrier signal that simply tells engineers the spacecraft is alive. Though the effort continues to try to fix the spacecraft, the odds of bringing it back to life are becoming slim, especially because its power supply will run out in 2026 at the very latest. Even if they manage to fix the issue now, the spacecraft has only a short time left regardless.

Considering the computers on this spacecraft, as well as its twin Voyager-2, have been operating continuously for almost a half century since their launch in 1977, their failure now is nothing to be ashamed of. The engineers that built both did well, to put it mildly.

As for Voyager-1’s future, even dead it will fly on into interstellar space, eventually getting within 1.5 light years of a star in the constellation Camelopardalis.

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JPL to lay off 8% of its work force plus 40 contractors

11:34 pm

Claiming the uncertainty of its federal budget allocation due to Congress’s inability to pass a new budget, the Jet Propulsion Lab (JPL) earlier today announced it was laying off 8% of its work force, 530 employees, plus 40 contractors.

In a memo to JPL staff Feb. 6, [director Laurie] Leshin said that a lack of a final 2024 appropriations bill — NASA is operating on a CR [continuing resolution] that runs until March 8 — forced the layoffs after taking other measures such as a hiring freeze and reductions in MSR [Mars Sample Return] contracts and other spending, as well as the earlier contractor layoffs. “So in the absence of an appropriation, and as much as we wish we didn’t need to take this action, we must now move forward to protect against even deeper cuts later were we to wait,” she wrote.

Uncertainty about how the Mars Sample Return project should be designed and built had caused Congress to express doubts about the project, with the Senate suggesting major cuts. NASA responded by loudly pausing the project and suggesting its own cuts. JPL has now followed up with these layoffs. Both have I think done so as a lobbying tactic, and as expected in this game of budget lobbying these actions have caused many legislators to scream in horror: “We really didn’t mean it! We really don’t want to cut anything!”

Expect our bankrupt Congress to fold and provide NASA and JPL the blank check it wants to fly a Mars mission that will cost billions, be years late, and likely be beaten to Mars by SpaceX’s Starship (which could do the job for a tenth the cost).

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February 6, 2024 Quick space links

3:33 pm

Courtesy of BtB’s stringer Jay. This post is also an open thread. I welcome my readers to post any comments or additional links relating to any space issues, even if unrelated to the links below.

 

  • Chinese pseudo-company is considering launching its rockets using “an electromagnetic catapult system”

    • They say it would increase the rocket’s payload capacity, but so would anti-gravity. We should believe this only when we see it.

 

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