Year: 2024

New computer simulations suggest Saturn’s rings are not young but formed at the same time as the solar system

9:12 am

A bright spot in Saturn's rings
Click for original source.

The uncertainty of science: Scientists doing computer simulations now posit that Saturn’s rings are not young, between 100 to 400 million years old as has been believed for the last few decades, but formed instead when Saturn formed, 4.6 billion years ago.

You can read their paper here [pdf].

The young age had been based on data from the Cassini orbiter, which showed the ring particles to be very bright and clean. If old those particles would have been darker as they accumulated dust over time on their surface. The new computer simulations suggest a process whereby those particles get “cleaned,” thus making it possible for the rings to be very old, possibly as old as Saturn itself.

Must I point out the uncertainties? The paper itself admits in its abstract “uncertainties in our models that assume no porosity, strength, or ring particle granularity.” Seems these assumptions make the conclusions very uncertain indeed.

Then again, the previous young estimates of the age of the rings had many similar assumptions and uncertainties. Essentially, we don’t have enough information to make any definitive determinations.

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T-Mobile initiates direct-cell-to-satellite texting using Starlink

8:50 am

As expected after the most recent Starlink launch, T-Mobile has now begun offering its customers beta registration for using Starlink satellites for texting in areas where no cell towers exist.

The free beta program is available to all T-Mobile customers with compatible devices and postpaid voice plans, the telco announced Dec. 16, although first responders will receive priority access due to limited initial capacity. The company declined to detail capacity and device restrictions but said the beta program would gradually expand to more devices via software updates. “Spots are limited but the service will be available in most areas and most of the time,” a T-Mobile spokesperson said.

The goal right now is to test the system and get user feedback.

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Thailand signs the Artemis Accords

8:26 am

Thailand yesterday became the 51st nation to sign the Artemis Accords, joining the American alliance in space.

The full list of nations now part of this American space alliance: Angola, Argentina, Armenia, Australia, Austria, Bahrain, Belgium, Brazil, Bulgaria, Canada, Chile, Colombia, Cyprus, Czech Republic, Denmark, Dominican Republic, Ecuador, Estonia, France, Germany, Greece, Iceland, India, Israel, Italy, Japan, Lithuania, Luxembourg, Mexico, the Netherlands, New Zealand, Nigeria, Panama, Peru, Poland, Romania, Rwanda, Saudi Arabia, Singapore, Slovakia, Slovenia, South Korea, Spain, Sweden, Switzerland, Thailand, the United Kingdom, the United Arab Emirates, the Ukraine, the United States and Uruguay.

Trump created the accords with the goal to create an alliance with enough clout to overcome the Outer Space Treaty’s restrictions on private property. Biden rewrote the goal to accomplish the exact opposite, as NASA states in all recent press releases about new nations joining:

The Artemis Accords are grounded in the Outer Space Treaty and other agreements including the Registration Convention, the Rescue and Return Agreement, as well as best practices and norms of responsible behavior that NASA and its partners have supported, including the public release of scientific data.

I expect there to be a shift back to the original goals in the second Trump administration.

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China and SpaceX complete launches

11:21 pm

Two launches today. First China launched four Earth observation radar satellites, its Long March 2D rocket lifting off from its Taiyuan spaceport in northeast China. No word where the rocket’s lower stages, using very toxic hypergolic fuels, crashed within China.

SpaceX then launched a GPS-type satellite for the Space Force, its Falcon 9 rocket lifting off from Cape Canaveral. Little was released about the payload and what information was released was not very informative. The first stage completed its fourth flight, landing softly on a drone ship in the Atlantic.

The leaders in the 2024 launch race:

130 SpaceX
62 China
16 Russia
13 Rocket Lab

American private enterprise still leads the rest of the world combined in successful launches 149 to 94, while SpaceX by itself leads the entire world, including American companies, 130 to 113.

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December 16, 2024 Quick space links

5:01 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.

  • On this day in 1984 the Soviet Union launched Vega-1
    The spacecraft not only flew past Venus on its way to flying past Halley’s Comet, it also put a lander on Venus and a French balloon in its atmosphere.
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    On the Space Show tomorrow

    4:36 pm

    I will be doing a long 90 minute-plus appearance with David Livingston on the Space Show tomorrow evening, beginning at 7 pm (Pacific). I hope my readers will consider calling in with questions or disagreements or comments. The show is always better with listener interaction.

    I definitely plan to talk about my proposal for rethinking NASA’s Artemis program, as outlined in this two-part essay:

    Part 1 of 2: What NASA’s next administrator should do if SLS and Orion are cancelled

    Part 2 of 2: De-emphasize a fast Moon landing and build a real American space industry instead December 11, 2024

    I very much would like to hear other people’s opinions about my suggestions.

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    A galactic eye in heaven

    12:30 pm

    A galactic eye in space
    Click for original image.

    Cool image time! The picture to the right, reduced and sharpened to post here, was taken by the Hubble Space Telescope as part of a project to study the star formation processes over time in this galaxy, located about 76 million light years away.

    A prominent bar of stars stretches across the centre of this galaxy, and spiral arms emerge from each end of the bar. Because NGC 2566 appears tilted from our perspective, its disc takes on an almond shape, giving the galaxy the appearance of a cosmic eye.

    As NGC 2566 gazes at us, astronomers gaze right back, using Hubble to survey the galaxy’s star clusters and star-forming regions. The Hubble data are especially valuable for studying stars that are just a few million years old; these stars are bright at the ultraviolet and visible wavelengths to which Hubble is sensitive. Using these data, researchers will measure the ages of NGC 2566’s stars, helping to piece together the timeline of the galaxy’s star formation and the exchange of gas between star-forming clouds and stars themselves.

    To get the full picture, astronomers have also obtained infrared data from the Webb Space Telescope and millimeter/submillimeter radio wavelength data from the ALMA telescope.

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    The Insight lander on Mars as seen from orbit over six years

    12:07 pm

    Insight as seen by MRO over six years
    Click for movie.

    Using photos taken by Mars Reconnaissance Orbiter (MRO) from 2018 to 2024, researchers have compiled a short movie showing how the dust around the Mars lander Insight changed over time.

    This video shows images taken by HiRISE between Dec. 11, 2018, just a couple weeks after InSight landed on Mars, and Oct. 23, 2024. In the images, InSight often appears as a bright, blue dot due to its reflection of sunlight. A dark halo was scorched into the ground by the spacecraft’s retrorocket thrusters; this halo fades away over time. Dark stripes that can be seen on the surface are tracks left by passing dust devils. [emphasis mine]

    You can see the movie here. The image to the right was the first picture taken by MRO only three weeks after landing.

    Insight eventually shut down because this dust accumulated on its solar panels, and the lander never was blessed with having a dust devil cross over it to blow that dust away. This video illustrates why. Out of the seven images making up the short movie, only three show dust devil tracks, and in each case only a few tracks are seen. No other tracks are detected.

    In other words, over six years this region simply did not get a lot of dust devils. The odds of one crossing over InSight was thus quite low. Ironically, the image to the right shows that a dust devil crossed very close to the lander about the time it landed in 2018, probably just beforehand since the dark scorch created by the lander’s thrusters cover the track. No dust devil ever got that close again.

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    Another American rocket startup gets a multi-launch contract

    10:25 am

    The American rocket startup Vaya Space announced today that it has been awarded a multi-launch contract to use its proposed Dauntless rocket to place up to 250 small satellites in orbit for the satellite startup Space Telecommunications.

    Vaya has been around since 2017, has won contracts with the Air Force in connection with developing its hybrid-solid-fueled rocket, and in 2022 completed a test suborbital launch. It hopes to launch Dauntless for the first time in 2026.

    This contract is probably like most launch contracts awarded to rocket startups. It allows the company to claim progress, while giving the satellite company the right to go elsewhere at no cost should the rocket not launch on time.

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    Northwestern University joins Giant Magellan Telescope consortium

    10:14 am

    In what might be a signal as to the future of the two competing giant telescopes being built in the United States, Northwestern University has now chosen to join the consortium building the Giant Magellan Telescope (GMT) in Chile.

    The university could have instead joined the consortium building the Thirty Meter Telescope (TMT) in Hawaii. That project however has been stalled for almost a decade due to opposition by DEI protesters who claim its construction would be a desecration to Mauna Kea, the mountain where it is being built.

    At the moment both telescopes are lobbying the National Science Foundation (NSF) for the additional funds needed for completion. The NSF however can’t fund both, and either has to chose one or the other, or get Congress to give it more money. Right now it has been lobbying for more money, even though it has recognized that GMT is farther along and is in better shape. This decision by Northwestern might be telling us that university officials don’t expect that additional NSF funding to come through, and thus it is putting its money on the project most likely to get finished.

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    Ispace awarded $5.83 million loan from Japanese government

    10:01 am

    Ispace landing map

    The planetary lander startup Ispace today announced that it has been awarded a $5.83 million loan from the Japan Finance Corporation, a government corporation designed to issue loans to encourage Japanese businesses.

    The money will be issued this month, and Ispace will have ten years to pay it back. Depending on whether the company is profitable or not, the interest rate will be either 0.5% or 4.15%.

    Ispace’s one lunar landing attempt so far, Hakuto-R1, was a failure when its software thought it was close to the ground at three miles altitude and shut off its engines. The company however is going to try again, with the launch of its second lander, dubbed Resilience, scheduled for a January 2025 launch. It will also carry the company’s own Tenacious micro-rover, and will hopefully land as shown in the map to the right, in the north of the Moon’s near side.

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