Category: Points of Information

Very brief descriptions, with appropriate links, of current or recent news items.

The same region on Ganymede, as seen by Voyager-1 in 1979 and Juno in 2021

11:30 am

Ganymede compared between Voyager-1 and Juno
Click for full image.

When the Jupiter orbiter Juno did a close pass of the moon Ganymede on June 7, 2021, it took four pictures, covering regions mostly photographed for the first time by Voyager-1 in its close fly-by in 1979.

Scientists have now published the data from this new fly-by. Though Juno’s higher resolution pictures revealed many new details when compared with the Voyager-1 images from four decades earlier, the scientists found no changes. The comparison image, figure 2 of their paper, is to the right, reduced and sharpened to post here.

A flicker comparison between the registered JunoCam and Voyager reprojected mosaics revealed no apparent new impact features. Given the high albedo of fresh craters on Ganymede, with high albedo ejecta deposits two or three times the diameter of the craters themselves, we argue that new craters as small as 250 m diameter would be detectable in images at these 1 km per pixel scales. Extrapolating Ganymede cratering rates from Zahnle et al. (2003) below 1 km, the probability of JunoCam observing a new crater over 12.2 million km2 in 42 years is 1 in 1500, consistent with none being observed.

In other words, at these resolutions finding no new impacts is not a surprise.

Of the new features detected, the Juno images could see more details in the bright rays emanating from the crater Tros (in the lower center of both images), and thus found “…terrain boundaries previously mapped as ‘undivided’ or as ‘approximate’, several large craters, and 12 paterae newly identified in this region.”

Paterae resemble craters but are thought to be a some form of volcanic caldera. Their geological origin however is not yet completely understood.

The paper’s conclusion is actually the most exciting:

The insight gained from this handful of images makes it likely in our opinion that new observations from the upcoming JUICE and Europa Clipper missions will revolutionize our understanding of Ganymede.

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SpaceX and the Ukraine resolve funding issues for Starlink terminals

9:39 am

According to a Ukrainian official, the Ukraine has worked out a method to pay for another 10,000 Starlink terminals by obtaining funding from several European nations.

Ukraine’s deputy prime minister Mykhailo Fedorov has announced that over 10,000 additional Starlink terminals will be sent to Ukraine in the coming months, confirming that issues regarding how to fund the country’s critical satellite internet service have been resolved.

The governments of several European Union countries are ready to share payment said Fedorov (who is also Ukraine’s minister for digital transformation) in an interview with Bloomberg, affirming that “As of now all financial issues have been resolved.” Fedorov did not publicly identify which governments are contributing towards the payments but confirmed that there’s currently no contract in place and that Ukraine will need to find additional funding by spring 2023.

Elon Musk had threatened to end Starlink support without some form of payment. It appears his threat, which was almost immediately retracted, forced some action by these governments.

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Kepler’s first discovered exoplanet is spiraling into its aging star

9:33 am

Measurements of the orbit of first exoplanet discovered by the Kepler space telescope have determined that its orbit is very slowly shrinking, and that it will eventually spiral into its aging sun.

In the case of Kepler-1658b, according to the new study, its orbital period is decreasing at the miniscule rate of about 131 milliseconds (thousandths of a second) per year, with a shorter orbit indicating the planet has moved closer to its star.

Detecting this decline required multiple years of careful observation. The watch started with Kepler and then was picked up by the Palomar Observatory’s Hale Telescope in Southern California and finally the Transiting Exoplanet Survey Telescope, or TESS, which launched in 2018. All three instruments captured transits, the term for when an exoplanet crosses the face of its star and causes a very slight dimming of the star’s brightness. Over the past 13 years, the interval between Kepler-1658b’s transits has slightly but steadily decreased.

The scientists think tidal forces are causing the orbit to shrink. The star itself is old and beginning to expand as it evolves towards its own stellar death.

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ISS spacewalk postponed because controllers had to maneuver station to avoid space junk

9:26 am

An American spacewalk to install new solar panels to ISS yesterday was suddenly scrubbed when ground controllers identified a piece of space junk that was going to fly within a quarter mile of the station.

While flight control teams were preparing for today’s U.S. spacewalk, updated tracking data on a fragment of Russian Fregat-SB upper stage debris showed a close approach to station. Based on this new data, flight control teams directed the crew to stop spacewalk preparations as the ground team stepped into procedures to perform a Pre-Determined Debris Avoidance Maneuver (PDAM.)

Russian controllers successfully used the engines on a docked Progress freighter today to complete the avoidance maneuver, firing those engines for 10 minutes and 21 seconds.

It appears the station was never in any danger.

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Virgin Orbit finally receives launch license from British bureaucracy

9:15 am

We’re here to help you! The UK’s Civil Aviation Authority has finally issued a license to Virgin Orbit to launch nine satellites from a Cornwall airport.

The launch date however has not yet been set, because it appears licenses for the nine satellites still need to be issued, though according to the article at the link, approval appears “imminent.”

The press release from the UK Space Agency brags about the speed in which this license was issued:

The UK Civil Aviation Authority granted the licences within 15 months, well within the expected timescales for these types of licences, putting the UK’s regulatory framework on a competitive footing with other international space regulators.

Hogwash. If the licensing process for every commercial launch in the UK is going to take this long, rocket companies are going to quickly find other places to launch from.

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Launch failure for Arianespace’s Vega-C rocket

8:58 am

The second launch of Arianespace’s Vega-C rocket, an upgrade from the Vega rocket that has launched previously, failed yesterday when a problem with the second stage occurred at 2 minutes 27 seconds into the flight.

Designated Vega Vehicle 22 (VV22), the rocket was the second Vega flight of the year and Arianespace’s fifth mission of 2022. VV22 was originally set to launch in November 2022, but a component in the upper composite in the payload fairing needed to be replaced. The launch failure occurred during stage 2 flight, with CEO Stephane Israel citing an “underpressure” indicated during that stage’s burn.

I have embedded video of the launch below, cued to T-30 seconds, just before launch. The rocket was carrying two Earth observation satellites built by Airbus.

The rocket itself has four stages, with the failure occurring when the second stage clearly did not maintain the rocket’s correct path. Though it appeared to be working, it was not providing enough power, so instead of continuing upward into space, the rocket fell back into the atmosphere.
» Read more

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December 20, 2022 Quick space links

3:51 pm

Courtesy of BtB’s stringer Jay.

 

  • Is Virgin Orbit a Phantom in the UK?

    • Interesting article, but in a word, the answer has always been “Yes!” Virgin Orbit wants to launch from Cornwall in the UK, but its factories and management is all U.S. based. Since its launch vehicle is an airplane, it is not likely to bring much else to the UK for a very long time. For anyone in Britain to think otherwise is to live in a fantasy world.

 

 

 

 

Three quick links providing graphics of China’s next generation crew spacecraft, suggesting it will be larger. None should be taken very seriously, as yet.

 

 

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Pushback: Blacklisting Virginia Tech soccer coach loses effort to get lawsuit dismissed

2:10 pm

Kiersten Hening, blacklisted by Virginia Tech
Kiersten Hening

Bring a gun to a knife fight: Charles Adair, the soccer coach for the woman’s team at Virginia Tech, has lost in his effort to dismiss a lawsuit against him by former player, Kiersten Hening, who he blacklisted from playing because she refused to kneel in support of Black Lives Matter during the National Anthem before a game.

Hening filed a lawsuit against Virginia Tech and Coach Adair in 2021 but Virginia Tech immediately attempted to file a motion to have the suit tossed. The athlete stated that when she refused to take part in the kneeling, which at the time was a virtue signal statement indicating public support for the Black Lives Matter movement, Adair began to insult and demean her as well as limiting her time to play during matches.

According to [U.S. District Judge Thomas T. Cullen], “Hening, who had been a major on-field contributor for two years prior to the 2020 season, also asserts that Adair removed her from the starting lineup or the next two games and drastically reduced her playing time in those games because she had engaged in this protected First Amendment activity. As a result, Hening resigned from the team after the third game of the season.” [emphasis mine]

You can read Cullen’s full decision here [pdf].

Cullen’s decision is intriguing not only because he not only threw out Adair’s effort to get the lawsuit dismissed, he also threw out Adair’s claim that he deserves “qualified immunity” as a public official. » Read more

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A congregation of Martian dust devils

12:13 pm

A congregation of Martian dust devils
Click for full image.

Cool image time! The photo to the right, rotated, cropped, reduced, and sharpened to post here, was taken on September 9, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows a spot on Mars where, as indicated by the many many tracks, dust devils routinely develop and travel across the surface.

Though this whole region appears to favor dust devils, within it are places that are even more favored. For example, the number of tracks on the northern and eastern slopes of that small hill at center left practically cover the surface, while the hill’s western and southern slopes are almost untouched.

Both the overview map and the global Mars map below provide the full context.
» Read more

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Perseverance’s planned route up onto the Jezero Crater delta

9:55 am

Perseverance's future route onto the delta
Click for original image.

Even as the Perseverance science team prepares to cache the ten first core samples on the surface of Mars for later pickup by a future Mars helicopter for return to Earth, they have also released the planned route they intend to follow as they drive the rover up onto the delta that flowed into Jezero Crater in the distant past.

The black line on the map to the right shows that route, with the black dots indicating points in which further core samples will likely be taken. The red dot indicates Perseverance’s present position, with the white line indicating its past travels. The green dot marks Ingenuity’s present position.

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Rocket Lab reschedules first Wallops launch to January

9:28 am

Having had to scrub the launch on December 18th and December 19th due of weather, Rocket Lab has now officially rescheduled its first Wallops launch to January.

The move of the planned launch window from December 2022 to early 2023 was driven by weather and the additional time that the National Aeronautics and Space Administration (NASA) at Wallops and the Federal Aviation Administration (FAA) required to complete essential regulatory documentation for launch. The delay in documentation left only two days in the originally scheduled 14-day launch window and both of those final remaining days were unsuitable for launch due to bad weather. The Mid-Atlantic Regional Spaceport within NASA’s Wallops Flight Facility is now closed for launch activity for the remainder of the December due to holiday airspace restrictions, preventing further launch attempts in 2022.

Rocket Lab originally wanted to launch from Wallops two years ago, but has been repeatedly stymied by government red tape. At that time the company wanted to use the software of its own flight termination system, a system that it has successfully used in New Zealand more than two dozen times, including several times where launch failures actually required the system to destroy the rocket. NASA said no, and instead insisted on spending two years apparently creating its own software which also requires the added presence of NASA officials during launch.

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Astronomers identify what they think are the Milky Way’s first stars

9:17 am

The concentration of ancient stars in the Milky Way's core region
The concentration of ancient stars in the Milky Way’s core region.
Click for originial image.

The uncertainty of science: Using data produced by the European space telescope Gaia, combined with computer analysis, astronomers think they have identified the Milky Way’s first stars, all located within 30,000 light years of the galaxy’s core region.

The researchers began by locating a sample of two million bright red giant stars with the right spectra, using computer neural network machine learning.

With that sample, it proved comparatively easy to identify the ancient heart of the Milky Way galaxy – a population of stars that Rix has dubbed the “poor old heart”, given their low metallicity, inferred old age, and central location. On a sky map, these stars appear to be concentrated around the galactic center. The distances conveniently supplied by Gaia (via the parallax method) allow for a 3D reconstruction that shows those stars confined within a comparatively small region around the center, approximately 30,000 light-years across

The stars in question neatly complement Xiang’s and Rix’s earlier study of the Milky Way’s teenage years: They have just the right metallicity to have brought forth the metal-poorest of those stars that, later on, formed the Milky Way’s thick disk. Since that earlier study provided a chronology for thick-disk formation, this makes the ancient heart of the Milky Way older than about 12.5 billion years.

While the uncertainties of this scientific result are huge, it still helps identify the beginnings of the Milky Way, its initial size, and the kind of stars that existed here at that time.

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