Tag: science

Next Ariane 5 launch postponed

11:39 am

Arianespace today announced that it has postponed its next Ariane 5 launch of two communications satellites, scheduled for October 22nd, because of issues with ground equipment.

Though there appear to be no issues with the rocket, this delay could effect the launch of the James Webb Space Telescope in December on another Ariane 5 rocket. Arianespace has said that it wants to complete this launch first, to make sure the fixes it completed on the rocket’s fairing are truly working.

It was those problems that shut down all Ariane 5 launches for almost a full year.

No new launch date has been set. Normally, ground equipment issues cause short delays, so we should be hopeful all will be fixed quickly and this launch will be quickly rescheduled and take off without problems.

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Pop-up clouds on Jupiter

9:12 am

Pop-up clouds on Jupiter
Click for full image.

Cool image time! The photo above was cropped and enhanced by citizen scientist Gerald Eichstädt from a raw Juno image taken during that spacecraft’s 37th orbit. I have reduced it slightly to post here.

The photo shows what he calls “pop-up” clouds floating above a much larger cloud eddy. Unfortunately, Eichstädt provides no scale, but I suspect this image would easily cover the Earth, with those white clouds probably far larger than the biggest hurricane on Earth.

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China resumes communications with Tianwen-1 Mars orbiter

8:45 am

With the Sun no longer between the Earth and Mars, China has re-established communications with its Tianwen-1 Mars orbiter.

According to the CNSA [China National Space Administration], the orbiter will enter the remote-sensing orbit of Mars in early November to carry out global detection and obtain scientific data such as morphology and geological structure, surface material composition and soil type distribution, atmospheric ionosphere, and space environment of Mars.

The orbiter will also relay the communication between the rover and Earth for the rover’s extended mission, the CNSA added.

Based on this information, full communications with the rover Zhurong will not resume until November because the orbiter needs to re-adjust its orbit.

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Curiosity’s new mountain views

1:14 pm

Curiosity's future route
Click for full image.

With the resumption of communications with Mars, following the two week hiatus because the Sun was in the way, Curiosity is about to begin its travels again. The view above, taken by the right navigation camera and reduced and annotated to post here, looks forward, with the red dotted line indicating the planned route.

The distinct white outcrop on the right top is the same spectacular outcrop I have highlighted previously.

At the moment however the rover is not going anywhere. Just before the hiatus the scientists had Curiosity move a short distance to crush some nearby nodules so that they could see their interior. At their update they post an image of one crushed nodule, and write the following:

[L]ook closely for very straight imprinted lines in the middle of flattened areas that appear slightly more grey. You can also see cracks, especially clearly on the right of the nodule in the image, but if you look around, you’ll find there are more of them. Some of the scratched areas are looking white, too. All those features will allow us an insight into the nodules and an interpretation beyond what we can otherwise see on the surface.

The image below, also taken by the right navigation camera and reduced to post here, looks back at Curiosity’s earlier travels, across the floor of Gale Crater about 1,500 feet below. The rim, about 25 miles away, can be seen through the atmospheric haze as the distant mountain chain.

See the orbital map at this post in September to get the context of what the two images are viewing. The top image looks south along the cliff line, the bottom looks almost due north.
Looking across Gale Crater
Click for full image.

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A collapsing north wall in Valles Marineris

2:05 pm

Mass wasting in Valles Marineris
Click for full image.

Cool image time! The photo to the right, rotated, cropped, and reduced to post here, was taken on July 17, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the scientists label as an alluvial fan.

I have also seen them label this kind of avalanche as mass wasting, where the material moves down slope suddenly in a single mass.

The image shows the aftermath of such an event, after a large blob of material broke free from the mountainside and slid almost as a unit downhill to settle more than two miles away on the floor of the canyon. The distance traveled and the blobby nature of the flow both reveal how the lower Martian gravity changes the nature of such events, compared to what you might see on Earth. The flows can travel farther, and can hold together as a unit easier.

The overview map below not only provides the context, but it tells us that such events are remarkably common in this place.
» Read more

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Scientists resume communications with U.S. Martian rovers

9:11 am

Example of first rover images downloaded following communications break
Click for full image.

Both U.S. Mars rovers Curiosity and Perseverance have resumed communications with Earth, each downloading a bunch of images that they had been programmed to take during the two week communications hiatus from October 3 to October 17, caused by the Sun being between the Earth and Mars.

Most of the images are a variation of the one to the right, reduced to post here, taken by Curiosity’s left hazard avoidance camera. As neither rover moved during the communications break, the scientists limited most photography to only a handful of cameras, with the photographs mostly confirming day to day that the rover and its instruments were functioning.

You can see all of Curiosity’s new images here. Perseverance’s new images can be viewed here. (To see the new Perseverance images click on “latest images.”)

A Curiosity team update today notes the work they plan to do in the coming days as they gear up for future travels. The Perseverance update today focused more on the paper published during the break that confirmed, using data from the rover, that Jezero Crater once contained a lake.

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Parker probe completes fifth Venus flyby

8:40 am

The Parker Solar Probe on October 16th successfully completed its fifth flyby of Venus, designed to lower its solar orbit around the Sun.

At just after 5:30 a.m. EDT, moving about 15 miles (24 kilometers) per second, the spacecraft swooped 2,370 miles (3,814 kilometers) above Venus’ surface. Such gravity assists are essential to the mission to bring Parker Solar Probe progressively closer to the Sun; the spacecraft counts on the planet to reduce its orbital energy, which in turn allows it to travel closer to the Sun and measure the properties of the solar wind near its source.

This was the fifth of seven planned Venus gravity assists. The flyby reduced Parker Solar Probe’s orbital speed by about 6,040 miles per hour (9,720 kilometers per hour), and set it up for its 10th close pass (or perihelion) by the Sun, on Nov. 21.

Parker Solar Probe will break its own distance and speed records on that closest approach, when it comes approximately 5.3 million miles (8.5 million kilometers) from the Sun’s surface — some 1.2 million miles (1.9 million kilometers) closer than the previous perihelion on Aug. 13 – while reaching 101 miles (163 kilometers) per second, or 364,621 miles per hour. Assisted by two more Venus flybys, in August 2023 and November 2024, Parker Solar Probe will eventually come within 4 million miles (6.2 million kilometers) of the solar surface in December 2024.

That speed record, 364,621 miles per hour, is the fastest any human built object as ever traveled.

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Update on Lucy: panels generating more than 90% of expected power

9:38 pm

According the Lucy science team, the spacecraft’s solar panels are generating more than 90% of the expected power at this stage of the mission, despite the fact that one panel did not deploy completely and has not latched in final position.

“We’re very happy to report that we are getting most of the power we expected at this point in the mission,” said Joan Salute, associate director for flight programs at NASA’s planetary science division. “It’s not 100%, but it is fairly close. So that is great news.’

In an interview with Spaceflight Now, Salute said the power output from the solar arrays appears to be “most likely above 90%” of the expected level of 18,000 watts. “We don’t know if it’s a latch problem, or that it is only partially deployed,” Salute said.

If correct, there is an excellent chance the mission will not be seriously hindered, even if they cannot get the panel fully deployed or latched. At the same time, there are worries about firing Lucy’s main engine for major course corrections with the panel unlatched. The first major course correction is scheduled for mid-November.

The engineers are presently reviewing their data. One option might be to order the spacecraft to re-attempt a full deployment, in the hope that the process will complete during that second attempt.

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The icy Phlegra Mountains on Mars

1:37 pm

Overview map

Cool image time! The Phlegra Mountains on Mars are probably the iciest mountains on the red planet, something I noted previously in an April 2020 essay, highlighting a half dozen images from the high resolution camera on Mars Reconnaissance Orbiter (MRO) that showed that iciness. As I stated:

Here practically every photograph taken by any orbiter appears to show immense glacial flows of some kind, with some glaciers coming down canyons and hollows [#1], some filling craters [#2], some forming wide aprons [#3] at the base of mountains and even at the mountains’ highest peaks [#4], and some filling the flats [#5] beyond the mountain foothills.

And then there are the images that show almost all these types of glaciers, plus others [#6].

The overview map above not only shows the locations of these six images in black, it also shows in red two of SpaceX’s four prime candidate landing sites for its Starship spacecraft. Note that #3 above is one of those sites.

The white rectangle in the Phlegra Mountains marks the location of today’s cool image below, taken on June 11, 2021 by MRO’S high resolution camera.
» Read more

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Today’s blacklisted American: Doctor banned from seeing patients because he has natural immunity

11:49 am

UC's ban of Kheriaty
The University of California’s action against Kheriaty.
Click for full image.

The modern dark age: The University of California has placed Dr. Aaron Kheriaty on administrative leave, preventing him from seeing any patients, because Kheriaty has sued the college for its vaccine mandate that refuses to recognize the documented stronger and safer effects of natural immunity over the COVID vaccines.

I was being placed on “Investigatory Leave” for my failure to comply with the vaccine mandate. I was given no opportunity to contact my patients, students, residents, or colleagues and let them know I would disappear for a month. Rather than waiting for the court to make a ruling on my case, the University has taken action.

…[H]alf of my income from the University comes from clinical revenues generated from seeing my patients, supervising resident clinics, and engaging in weekend and holiday on-call duties. So while on leave my salary is significantly cut. Furthermore, my contract stipulates that I am not able to conduct any patient care outside the University: to see my current patients, or to recoup my losses by moonlighting as a physician elsewhere, would violate the terms of my contract.

Kheriaty, who has had the Wuhan flu (along with his entire family) and now had natural immunity, opposes mandating a vaccine for such individuals because the costs far outweigh the benefits. As he writes:
» Read more

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Early solar system had gap separating its inner and outer regions

9:29 am

New research looking at the make-up of asteroids now suggests that the early solar system had a gap that separated the formation of planets between its inner and outer regions.

Earlier data had suggested that asteroids come in two fundamentally different groups. This new research, looking the magnetic field strength of these two groups, has confirmed this distinction, and provided additional information about the formation process of each.

Surprisingly, they found that their field strength was stronger than that of the closer-in noncarbonaceous meteorites they previously measured. As young planetary systems are taking shape, scientists expect that the strength of the magnetic field should decay with distance from the sun.

In contrast, Borlina and his colleagues found the far-out chondrules had a stronger magnetic field, of about 100 microteslas, compared to a field of 50 microteslas in the closer chondrules. For reference, the Earth’s magnetic field today is around 50 microteslas.

A planetary system’s magnetic field is a measure of its accretion rate, or the amount of gas and dust it can draw into its center over time. Based on the carbonaceous chondrules’ magnetic field, the solar system’s outer region must have been accreting much more mass than the inner region.

In other words, the accretion of planets in the outer region was faster and producing larger objects, while the inner region was slower and producing smaller objects. The data also suggests that gap existed about 4.5 billion years ago, at about the location of the asteroid belt. All in all, this scenario matches the solar system we see today.

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A Lucy solar panel on Lucy fails to latch properly after deployment

8:40 am

Partly deployed panel

Engineers at Lockheed Martin (the prime contractor) and Northrop Grumann (which built the panels) are now troubleshooting an issue with one of the solar panels on the asteroid probe Lucy, which failed to latch properly after deployment.

The NASA graphic to the right illustrates this issue, though the graphic might not accurately portray the exact circumstance at Lucy. To get more solar power, Lucy’s panels are larger, and thus were designed to unfurl like a fan rather than the more commonly used accordion design. One panel has not completed that unfurling.

NASA’s announcement tries to minimize the issue but this quote from the link makes it clear that this could be a very big problem.

It’s not yet clear whether the array in question is, in fact, fully deployed but not latched in place or whether it did not reach full deployment and is not generating the same amount of power as its counterpart. It’s also not yet clear whether Lucy can safely fire its maneuvering thrusters with an unlatched array.

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ULA’a Atlas-5 successfully launches the Lucy asteroid probe

6:08 pm

ULA’a Atlas-5 rocket early this morning successfully launched the Lucy asteroid probe on a 12 year mission to study eight Trojan asteroids over a period from 2025 to 2031. One tidbit about the mission is especially creative:

Scientists named the Lucy mission after the fossilized remains of a human ancestor, called Lucy by the scientists who discovered her in Ethiopia in 1974.

The leaders in the 2021 launch race:

36 China
23 SpaceX
17 Russia
4 Northrop Grumman
4 ULA

The U.S. and China are once again tied in the national rankings, at 36 each.

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Dry Martian chaos

1:52 pm

Dry chaos on Mars
Click for full image.

On Mars, one of the most common kinds of landscape is called chaos terrain. Made up of mesas, buttes, and cross-cutting random canyons, this geology is not seen on Earth, and when first identified by scientists in early orbital pictures in the 1970s, it baffled them. While it is clear that some form of erosion process caused it, the scientists did not have enough data then to figure out what that process was.

Today scientists have a rough theory, based on what they now know about Mars’ overall geology and its climate and orbital history. The canyons of chaos terrain were originally fault lines where either water or ice could seep through and widen. See this January 2020 post for a more detailed explanation.

Most of the cool images I have posted of chaos terrain have been in places in the mid-latitudes that are covered with glaciers. See for example this December 2019 post of one particular mesa in glacier country, with numerous glaciers flowing down its slopes on all sides. That mesa is quite typical of all such mesas in the mid-latitudes.

Today’s cool image above, cropped to post here, takes us instead to the Martian very dry equatorial regions. The photo was taken on May 17, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), and like mid-latitude chaos, it shows a collection of random mesas with canyons cut almost randomly between.

Unlike the mid-latitudes, however, there is no evidence of glaciers here. Instead, the canyons and mesa slopes are covered with dust, shaped into wind-blown dunes.

As always, the overview map below gives us some context.
» Read more

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Hubble data detects persistent water vapor on one of Europa’s hemispheres

1:30 pm

Using data from the Hubble Space Telescope spanning sixteen Earth years, scientists have detected the presence of water vapor on Europa, but strangely spread only across one of the moon’s hemispheres.

Previous observations of water vapor on Europa have been associated with plumes erupting through the ice, as photographed by Hubble in 2013. They are analogous to geysers on Earth, but extend more than 60 miles high. They produce transient blobs of water vapor in the moon’s atmosphere, which is only one-billionth the surface pressure of Earth’s atmosphere.

The new results, however, show similar amounts of water vapor spread over a larger area of Europa in Hubble observations spanning from 1999 to 2015. This suggests a long-term presence of a water vapor atmosphere only in Europa’s trailing hemisphere – that portion of the moon that is always opposite its direction of motion along its orbit. The cause of this asymmetry between the leading and trailing hemisphere is not fully understood.

First, it must be emphasized that the amounts of atmospheric water being discussed are tiny, so tiny that on Earth we might consider this a vacuum.

Second, that the water vapor is only seen on the trailing hemisphere suggests there is some sort of orbital influence involved, though what that influence is remains unknown.

Hopefully when Europa Clipper finally arrives in orbit around Jupiter in 2030, with a path that will fly past Europa fifty times, we will some clarity on these questions.

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A gecko on Mars

12:24 pm

Gecko on Mars
Click for full image.

Today’s cool image is also today’s picture of the day from the science team of the high resolution camera on Mars Reconnaissance Orbiter (MRO. That picture, rotated, cropped, and reduced to post here, can be seen to the right. As the caption authors Sharon Wilson and Sarah Sutton write:

The smooth volcanic surfaces in the Gordii Fossae region are sometimes interrupted by long, narrow troughs, or fissures. These fissures form when underground faults, possibly involving magma movement, reach the near-surface, allowing material to collapse into pits or an elongated trough. This fissure appears to have erupted material that flowed onto the surface.

If you use your imagination, this trough resembles a gecko with its long tail and web-shaped feet!

This impression is even more evident in the wider image taken by MRO’s context camera below.
» Read more

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Webb telescope finally arrives at launch site in French Guiana

2:54 pm

Webb deployment

After almost twenty years of construction (a decade behind schedule) and a cost of $10 billion, ($9.5 billion over budget), the James Webb Space Telescope today arrived at the processing facility at Arianespace’s French Guiana spaceport, where it will be prepared for a December 18, 2021 launch on an Ariane 5 rocket.

Once launched the telescope, which is not a replacement for Hubble because it observes in the infrared (not optical) and is optimized for deep space cosmology, will take two weeks to reach its orbital position about a million miles from Earth, as shown in the graphic.

Let us all cross our fingers and toes that it all works as designed, for if it doesn’t this will be the biggest failure ever in the history of NASA.

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Today’s blacklisted American: Brownstone Institute blackballed by LinkedIn for associating with famed Harvard epidemiologist

11:12 am

They’re coming for you next: The non-profit Brownstone Institute, founded in 2021 to provide an outlet for educated dissent on science and economic issues, has found itself repeatedly censored by LinkedIn in the past two weeks because one of its founders is famed Harvard epidemiologist Martin Kulldorff.

Brownstone Institute: Censored

If you are a regular reader of this column you might remember Kulldorff’s name. He was blacklisted by the CDC, Twitter, and LinkedIn in late August because he dissents from the oppressive lockdown policies those organizations advocate. He was also one of the leading authors of the Great Barrington Declaration [also available here a pdf], which strongly opposes the policies of lockdowns, mandates, and the other totalitarian actions taken by governments since 2020, and instead calls for the more traditional (and successful) “focused” approach for dealing with epidemics and diseases: Protect the vulnerable (the old and sick) from the disease while letting everyone else (the young and healthy) live normal lives and thus get infected quickly, become immune, and thus squelch off the virus.

Kulldorff is also one of the world’s preeminent experts on vaccine safety and “helped develop the CDC’s current system for monitoring potential vaccine risks.”

Anyway, it appears that on October 1st, LinkedIn suddenly discovered that Kulldorff was one of the senior scholars at the Brownstone Institute, and began deleting the institute’s posts.
» Read more

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Dusty chaos in Martian canyons

1:37 pm

Outcrops in dusty chaos on Mars
Click for full image.

Cool image time! The photo to the right, cropped and reduced to post here, was taken on May 30, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows the dusty dry floor of the chaos region of rough terrain in a side canyon of Valles Marineris, near its outlet. The color strip and the bright outcrops suggest that this terrain contains interesting minerals and resources. To determine exactly what those materials are however requires more information not available in this photo.

This ancient chaos terrain is the leftover eroded sea floor of a intermittent inland sea, leftover water from the catastrophic floods that are theorized to have flowed out of Valles Marineris and carved its gigantic canyons.

The overview map below shows this hypothesized sea.
» Read more

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Ancient fossil river in the very dry equatorial regions of Mars

1:27 pm

Inverted Channel on Mars
Click for full image.

Cool image time! The photo to the right, rotated, cropped, and reduced to post here, was taken on August 29, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the scientists label an “inverted channel in Arabia Terra,” a small example of the more than 10,000 miles of fossilized rivers in this region on Mars that scientists have identified using MRO.

They are made of sand and gravel deposited by a river and when the river becomes dry, the channels are left upstanding as the surrounding material erodes. On Earth, inverted channels often occur in dry, desert environments like Oman, Egypt, or Utah, where erosion rates are low – in most other environments, the channels are worn away before they can become inverted. “The networks of inverted channels in Arabia Terra are about 30m high and up to 1–2km wide, so we think they are probably the remains of giant rivers that flowed billions of years ago. [emphasis mine]

Since this fossilized river is located at 11 degrees north latitude, smack in the middle of the dry equatorial regions of Mars, it has certainly been a dry desert for a very long time. You can see how barren the terrain appears by looking at the wider view afforded by MRO’s context camera below.
» Read more

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As expected, Pluto’s atmosphere is freezing as its orbit takes it from the Sun

10:48 am

Data from ground-based telescopes has now confirmed that Pluto’s nitrogen atmosphere has begun it annual winter freeze out as the planet’s somewhat elliptical 248-year-long orbit takes it away from the Sun.

For about 25 years, Pluto has been moving farther and farther away from the sun, so its surface temperature has been going down. And with these recent observations, the researchers found evidence showing that Pluto’s atmosphere is actually refreezing back onto its surface as the dwarf planet gets colder and colder. Pluto is so far from the sun that, as time goes on, it will get distinctly farther away (and colder) before getting closer to the sun in other regions of its immense orbit.

The astronomers were able to detect this refreezing by observing the planet as it eclipsed a star in 2018.

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Data from Perseverance confirms Jezero Crater once held a lake

6:52 am

figure 5 from paper showing ancient lake in Jezero Crater

According to a newly published paper, the data obtained by the rover Perseverance has confirmed and refined what orbital data has suggested, that Jezero Crater once held a lake. From the abstract:

We analyze images taken by the rover in the three months after landing. The fan has outcrop faces that were invisible from orbit, which record the hydrological evolution of Jezero crater. We interpret the presence of inclined strata in these outcrops as evidence of deltas that advanced into a lake. In contrast, the uppermost fan strata are composed of boulder conglomerates, which imply deposition by episodic high-energy floods. This sedimentary succession indicates a transition, from a sustained hydrologic activity in a persistent lake environment, to highly energetic short-duration fluvial flows.

In other words, the crater first held a lake, which as it slowly dried out was periodically renewed by flash floods. The distinct delta of material that made Jezero Crater the prime landing site was apparently formed during the period when the lake existed. The conditions that caused the subsequent flash floods is as yet not been determined, though it likely is related to the red planet’s long term evolution.

The image above, figure 5 from the paper, shows the inferred lake in that early history. The red cross marks Perseverance’s landing site.

This data reinforces the fundamental scientific mystery of Mars. It shows evidence that liquid water once flowed on the surface of Mars, even though other long term data of the planet’s history says the Martian atmosphere has been too thin and too cold to allow that to happen. There is evidence that the atmosphere might have once been thicker, but no computer model or theory has been able to produce a time when it was warm enough.

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Chang’e-5 lunar samples youngest ever found

6:28 am

The uncertainty of science: The lunar samples returned to Earth by China’s Chang’e-5 lander have been found to be the youngest ever found, about two billion years old and a billion years younger than any other previous sample, with a composition that confirms the material in this area was also the youngest volcanism so far found on the Moon.

Collecting young lunar rocks was one of the main objectives for the Chang’e-5 mission, which sent a lander to the Moon in December 2020. The craft grabbed 1.7 kilogram (4 pounds) of lunar regolith from the vast volcanic plain of Oceanus Procellarum and flew back to Earth within the month. Observations from lunar orbit had identified this mare to be younger than other areas by its paucity of craters, which suggested that the lava there had flowed more recently. By dating the samples returned to Earth, the scientists confirm that volcanism occurred later in Oceanus Procellarum than other areas of the Moon.

Many news stories are claiming that the young age of these samples is a surprise, but this isn’t true. It was expected, as the quote above indicates.

However, the composition of the rocks did not match what was expected. Though created by volcanism, it appears the material did not have kind of composition seen in other lunar volcanic rocks. This is now a new puzzle for scientists.

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Today’s blacklisted American: Woman denied kidney transplant in Colorado because she is unvaccinated

1:10 pm

The unvaccinated denied healthcare in Colorado
No healthcare in Colorado permitted for the unvaccinated. Let them die!

Persecution is now cool! A woman who has stage 5 renal failure was suddenly told by UCHealth (University of Colorado Health) — just before her kidney transplant operation — that she was banned from the hospital because both she and her donor are unvaccinated.

“Here I am, willing to be a direct donor to her. It does not affect any other patient on the transplant list,” Jaimee Fougner, Leilani Lutali’s kidney donor, told CBS4. “How can I sit here and allow them to murder my friend when I’ve got a perfectly good kidney and can save her life?”

Lutali said she received a letter from Colorado health system UCHealth at the end of September explaining that she and Fougner have 30 days to begin the vaccine process. They would be removed from the kidney transplant list if they refuse the shots. “I said I’ll sign a medical waiver. I have to sign a waiver anyway for the transplant itself, releasing them from anything that could possibly go wrong,” said Lutali. “It’s surgery, it’s invasive. I sign a waiver for my life. I’m not sure why I can’t sign a waiver for the COVID shot.”

According the article, when they first scheduled the surgery in August they were told by the hospital that being unvaccinated was not a problem. This changed suddenly in late September, at the last moment.
» Read more

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The wavy and beautiful edge of the northern ice cap of Mars

12:32 pm

The scarp of the north pole icecap on Mars
Click for full image.

Cool image time! The photo to the right, cropped and reduced to post here, was taken on August 7, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows the many layered scarp that forms the edge of the northern polar ice cap on Mars, probably more than 2,000 feet high.

Those layers are significant, as they indicate the many climate cycles that scientists think Mars has undergone over the eons as the red planet’s rotational tilt, or obliquity, rocked back and forth from 11 degrees inclination to as much as 60 degrees. At the extremes, the ice cap was either growing or shrinking, while today (at 25 degrees inclination) it appears to be in a steady state.

Why the layers alternate light and dark is not known. The shift from lighter colors at the top half and the dark bottom half marks the separation between the top water ice cap and what scientists label the basal unit. It also marks some major change in Mars’ climate and geology that occurred about 4.5 million years ago.
» Read more

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Sunspot update: The boom in sunspots returns!

12:11 pm

It is time for my monthly sunspot update, based on the most recent NOAA monthly graph, showing the changes in the Sun’s sunspot activity during September. That graph is below, annotated to show the previous solar cycle predictions and thus provide context.

In September sunspot activity boomed once again, producing the most sunspots in a month since 2016 and ending the slight drop in activity in August to return to the pattern the Sun has exhibited since the end of solar minimum. Consistently the number of sunspots on the visible hemisphere of the Sun since 2020 has exceeded the April 2020 prediction of the NOAA scientist panel, as indicated by the red curve in the graph.

» Read more

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Land of Martian slope streaks

12:37 pm

Land of Martian slope streaks
Click for full image.

Cool image time! The photo to the right, cropped and reduced to post here, was taken on May 21, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows a typical example of the many slope streaks found in the rough and very broken region north of the Martian volcano Olympus Mons, the largest in the solar system.

See this May 2019 post for a detailed explanation of slope streaks. While they appear to be avalanches, they do not change the topography of the ground, sometimes flow over rises, and appear to be a phenomenon entirely unique to Mars. While no theory as yet explains them fully, the two most favored postulate that they are either dust avalanches or the percolation of a brine of chloride and/or perchlorate in a thin layer several inches thick close to the surface. In both cases the streak is mostly only a stain on the surface that fades with time.

The location of this cool image however tells us something more about them.
» Read more

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BeppiColombo’s first images of Mercury

10:52 pm

Mercury by BebiColomo
Click for full image.

This past weekend the European/Japanese duel-orbiter mission made its first flyby of Mercury, taking its first images of that planet.

The photo to the right is one example, cropped and reduced slightly to post here. It was taken by the spacecraft’s monitoring cameras, designed for engineering purposes, which means the resolution is not very high and the camera is positioned so that parts of the spacecraft were visible in each shot. For example, the white strut in the lower right is the spacecraft’s magnetometer boom, which also was used to gather data during the flyby.

Still, the photos demonstrated that the spacecraft is pointing correctly and on course. It will complete five more Mercury fly-bys before going into orbit in 2025.

The next flyby will occur in June ’22.

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