Month: October 2019

October 14, 2019 Zimmerman Space Show appearance

9:10 am

David Livingston has now posted the podcast for my two hour appearance on the Space Show last night, making it available for download.

David had this to say about the show in an email this morning, “Thanks for a good, passionate, and opinionated discussion. A Zimmerman show at its best!”

The discussions on Starship, Musk, and the Thirty Meter Telescope I think were especially interesting. Other topics included the debt vs NASA’s budget, China’s future in space, and the lies of the Green New Deal.

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Europe schedules new parachute tests for ExoMars 2020

8:59 am

Following the failure on all previous tests of the parachutes for its ExoMars 2020 Mars lander, the European Space Agency has now made some design changes and is planning to do additional tests in the first quarter of 2020.

ESA has also requested support from NASA to benefit from their hands-on parachute experience. This cooperation gives access to special test equipment at NASA’s Jet Propulsion Laboratory that will enable ESA to conduct multiple dynamic extraction tests on the ground in order to validate any foreseen design adaptations prior to the upcoming high altitude drop tests.

The next opportunities for high altitude drop tests are at a range in Oregon, US, January–March. ESA is working to complete the tests of both the 15 m and 35 m parachute prior to the ExoMars project’s ‘qualification acceptance review’, which is planned for the end of April in order to meet the mission launch window (26 July–11 Aug 2020).

Their schedule is incredibly tight, since their launch window to Mars is in July 2020, and if they fail to meet it the launch will have to be delayed two years until the next launch window.

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Unexplained issues with assembling SLS’s core stage?

8:52 am

It appears that in its effort to finally assembly SLS’s core stage so that it can be tested prior to its first launch, probably in 2021, NASA and Boeing recently experienced an issue that required “corrective action.”

Neither NASA nor Boeing have provided any detailed explanation for what the issue was, but according to the story at the link,

…one source suggested to Ars that Boeing technicians are having difficulty attaching the large rocket engines in a horizontal configuration rather than a vertical position. NASA and Boeing made a late change to the final assembly process, deciding to mate pieces of the core stage horizontally rather than vertically to save time. However, this source said horizontal mating of the engines has created problems.

Despite this, NASA officials said progress is being made. “NASA and Boeing are expected to have the first engine soft mated to the core stage next week,” Tracy McMahan, a spokesperson for Marshall Space Flight Center, said on Saturday. “However, there are many steps in engine installation that have to occur before the installation is complete.”

I applaud them for finally trying to “save time,” a concept that up until now the entire SLS project has never had much interest in. That this effort ended up causing a delay however is symptomatic of the design of the project, which remains cumbersome and inefficient, a fault not of the engineering but of some fundamental decisions at the top by Congress and NASA’s management.

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Preparations begin for China’s next Long March 5 launch

8:44 am

China has apparently begun preparations for a long-delayed third and critical Long March 5 launch by the end of this year.

Two cargo transport ships left port on the Yangtze river late Friday Eastern for the northern city of Tianjin. They are expected to collect components of a third Long March 5 heavy-lift launch vehicle, which has been grounded since a 2017 launch failure.

After expected arrival Oct. 15 and subsequent loading, Yuanwang-21 and 22 ships will deliver the rocket to the island province of Hainan. Launch preparations requiring about two months will then commence at the Wenchang Satellite Launch Center.

Without this rocket, which is the world’s second most powerful after the Falcon Heavy, China cannot build its space station or launch either of its 2020 Mars orbiter or its Chang’e-5 lunar sample return mission.

The rocket’s failure on its second launch in July 2017 occurred because of an engine failure that required a major redesign. Since much of China’s space technology is initially stolen from others, it does not surprise me that they had problems. When you steal this kind of technology, rather than develop it yourself, your engineers might not fully understand it to the degree necessary to make it work.

At the same time, the track record of China’s engineers in eventually figuring out how their stolen technology works and even improving it has been very good. I would expect this December launch to be successful.

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InSight’s mole digs an inch

8:33 am

The InSight science team today tweeted that their attempt to use the lander’s robot arm to help the mole push downward in its effort to insert a heat sensor fifteen feet into the Martian interior has resulted in a gain of about an inch or three centimeters.

This success, small as it seems, is important in that it proves that the reason the drill had been stopped penetrating downward was not because of the presence of a rock, but because the drill hole had become so wide that the drill no longer had side friction to hold it in place. They are now using the arm to give the mole that friction.

The goal was to insert to heat sensor five meters or about sixteen feet into the ground. They are presently a little over a foot down. If this effort has really succeeded, they can then proceed to drill the remaining distance.

One issue however is whether the unexpected weak and porous nature of the soil, which allowed the hole to become so wide, might affect any data produced by the heat sensor. This is presently unknown, but it is a significant question that the scientists involved must ask. If the sensor ends up inside a very wide shaft that allows the surface environment to reach the sensor then it will not really be measuring the temperature of the Martian interior.

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The bad consequences from California’s imposed blackouts

12:54 pm

Link here. The blackout was imposed to avoid electric lines from causing wildfires. However, the reason there is a risk of wildfires is not because of electricity but because the Democratically-controlled government in California would rather inconvenience its citizens than simply clear the brush from the forests and thus to lower the risk of wildfires.

The consequences? Supermarkets might go out of business because of food spoilage. Cancer research was destroyed. And at least one man died because his oxygen supply was cut off when the power shut down.

And in a remarkable example of irony, home owners with solar power discovered that solar power doesn’t work if there is a blackout, as their power is not fed to their homes but into the electric grid. With the grid shut down, the electricity from their panels vanished into the ether. Similarly, the owners of electric cars have suddenly discovered their cars won’t work without a power supply.

But don’t worry Californians! You clearly want Venezuela and the Democrats who run California sincerely and passionately want to give it to you. These blackouts are only the beginning. Socialism and centralized rule by government always leads to bankruptcy, starvation, failure, and the deaths of millions. And it has done it so many times in the past century that it makes me despair for a human race that cannot seem to learn anything from these horrific lessons.

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Skylights into Martian lava tube?

12:31 pm

Possibly connected skylights into lava tube
Click for full image.

Close-up of skylights
Click for full image.

Cool image time! In the archive of images from the high resolution camera on Mars Reconnaissance Orbiter (MRO) I came across the uncaptioned image on the right, dubbed “Possibly Connected Lava Tube Skylight Pair in Tharsis Region.”

The top image, cropped and reduced to post here, is a wide view, showing a narrow depression oriented in a north-south direction. Downhill is to the north, with the caldera of the giant volcano Arsia Mons to the south. The white box indicates the area covered by the bottom image, cropped and expanded to post here. Within this close-up are two dark spots, each about 150 feet across.

The two dark spots surely look like small pit openings. Their alignment with the north-south depression strongly suggests that an underground lava tube is below. That this depression is also aligned with the downhill slope further reinforces this supposition.

The depression itself also aligns with the gigantic fault that runs from the northeast to the southwest through all three of the giant Tharsis Bulge volcanoes. Arsia Mons is the southernmost of the three. It is also where that fault is most clearly expressed by two dramatic breaks in the volcano’s rim in the northeast and southwest, as seen in the overview image below. Scientists have taken of lot of images of these breaks in an effort to better understand the geology and how it fits in with the formation of the volcanoes.

Overview of Arsia Mons

However, a review of the entire image archive of MRO’s high resolution camera shows that scientists have taken very few close-up images in this region. The black box in the overview map on the right is the location of this image. As of now, only three other high resolution images, as indicated by the white boxes, have been taken by MRO of this part of the volcano’s north slope.

That the skylights and depression align with this giant fault is not evidence that this supposed lava tube is linked to that fault. Lava will flow down the mountain’s slopes, fault or no fault. At the same time, the fault’s existence is also going to encourage north-south cracks and fissures, which in turn could have served as a convenient flow route for the lava. Without a closer look, on site, it is hard to know one way or the other..

I’ve located a few more lava related cool images in the MRO archive, so I’m going to make this week lava week on Behind the Black. Stay tuned!

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SpaceX extends Boca Chica purchase deadline, will do new appraisals

4:03 pm

SpaceX has agreed to do new appraisals on the private homesites in Boca Chica that it wishes to purchase, while also agreeing to extend the deadline for owners to accept their offer.

It appears that Musk invited the owners to his Starship presentation on September 28, and then met with some of them afterward to discuss the situation face to face.

Musk met with seven villagers following the presentation, though others … gave up waiting for him to show.

Cheryl Stevens, who owns a house down the street from the Heatons, did stick around. The meeting was “sort of testy” at first, as the owners confronted Musk with their concerns after waiting a long time, though the mood eventually lightened, she said. “We all had things we wanted to say,” Stevens said. “He was good about listening to what we said, then referring to what we said. … I left there feeling OK. Overall it was fairly cordial, just testy at the beginning. At least we felt like we were heard.”

At the same time, she said, “I’m not interested in giving my house away.”

This is the kind of thing that Musk does very well. Rather than stay in his ivory tower, as most modern big corporate heads, he talks with people directly. I expect SpaceX will end up offering these people deals where they can buy homes relatively comparable to what they have now, in a similar location. This will engender good will, and good press for the company.

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First SLS launch will likely be delayed again

3:57 pm

Surprise! Surprise! NASA officials hinted at a conference October 10th that the first SLS launch will likely be delayed again, from late in 2020 to the first half of 2021.

This actually isn’t news. When NASA committed in July to doing a full static fire test of SLS’s first stage it almost guaranteed that the first launch could not happen before 2021.

What this means is that Trump’s desire to have a lunar landing, with SLS, by 2024, is practically impossible, even if Congress should agree to provide full funding, which it has not. SLS as designed simply cannot meet the launch pace required to get a lunar landing by 2024. It is too cumbersome, designed badly in terms of management and efficiency.

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Astronomers identify likely origin star for interstellar Comet Borisov

3:49 pm

Astronomers have backtracked the path of interstellar Comet Borisov to identify its likely origin.

When you rewind Comet Borisov’s path through space, you’ll find that 1 million years ago, the object passed just 5.7 light-years from the center of Kruger 60, moving just 2.13 miles per second (3.43 kilometers per second), the researchers wrote.

That’s fast in human terms —— about the top speed of an X-43A Scramjet, one of the fastest aircraft ever built. But an X-43A Scramjet can’t overcome the sun’s gravity to escape our solar system. And the researchers found that if the comet were really moving that slowly at a distance of no more than 6 light-years from Kruger 60, it probably wasn’t just passing by. That’s probably the star system it came from, they said. At some point in the distant past, Comet Borisov likely orbited those stars the way comets in our system orbit ours.

The remains some uncertainty about these calculations because astronomers are still gathering data on the comet’s path.

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New owners for Stratolaunch

6:07 pm

Capitalism in space: Stratolaunch announced today that it is now under new ownership, without identifying who that new owner is.

The company offered few other details in a statement released to media Friday. It was the first official update on the status of Stratolaunch since its huge rocket carrier aircraft completed its first — and so far only — test flight in April. “Stratolaunch LLC has transitioned ownership and is continuing regular operations,” the company said in a statement. “Our near-term launch vehicle development strategy focuses on providing customizable, reusable, and affordable rocket-powered testbed vehicles and associated flight services.

Stratolaunch did not identify its new owner Friday, or details on the type of launch vehicle it seeks to develop.

It would be a massive understatement to say their announcement is vague and lacking in details.

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Alexei Leonov, the first man to walk in space, dies

12:59 pm

R.I.P. Alexei Leonov, the first man to walk in space, passed away today at the age of 85.

Leonov also participated in the Apollo-Soyuz mission, the first joint mission between the U.S. and the Soviet Union.

The obituary notes Leonov’s sense of humor. I met Leonov in 2003 when I was in Moscow interviewing cosmonauts for my book Leaving Earth and found him to be a jovial, friendly, and open person.

He told me one story that I thought was significant. He noted the American practice in the 1960s to openly discuss everything that happened in its space effort worked to enhance our achievements, while the secrecy of the Russians only devalued anything they did. As he said,

The honesty of the American press made [those space achievements] more persuasive, more influential. Every little problem was written about in great detail, so that the image of the American astronauts grew, making them heroes. It was a much more clever approach. [Leaving Earth, p. 172]

Leonov for years would accompany astronauts on the bus on their way to the launchpad, providing encouragement. When Helen Sharman flew in space as a tourist in 1991 he gave her

…a ridiculous-looking, pink, frilly jumpsuit. “I got one of the ladies at the hotel to make it up for you,” Leonov said, his sweet round face lighting up in an infectious grin. “Just for fun.” [Leaving Earth, p. 301]

She wore it the first day in space, to the silly delight of everyone.

In the long endless future of humanity in space, only beginning now, Leonov will always hold an honored place.

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Leftist rioters attack Trump supporters leaving Trump rally

10:15 am

They’re coming for you next: As has become routine now from fascist Democratic Party supporters, a mob of several hundred rioters in Minnesota yesterday attacked Trump supporters as they were leaving last night’s Trump rally.

It appears individuals were surrounded and attacked. Others had their MAGA hats stolen, which were then burned. In addition, reporters were maced, and it also appears the police stood by while this was happening.

The Democratic mayor of Minneapolis vehemently opposed this rally, trying and failing to squelch it with an unreasonable security fee. It appears he has decided to allow violence to act for him instead.

This is today’s Democratic Party, a fascist operation that tries to squelch the free speech of its political opponents, by any means necessary. If legal manipulation fails, they then send out their jack-booted thugs.

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Air Force selects 8 launch companies for future contracts

9:56 am

Capitalism in space: The Air Force yesterday announced that it has selected eight launch companies as part of a program allowing it to order future launch contracts quickly.

SpaceX, Xbow Launch Systems, Northrop Grumman, Firefly Aerospace, United Launch Alliance, Aevum, Vox Space and Rocket Lab have been selected to provide launch services in the Orbital Services Program-4 [OSP-4] — a $986 million procurement of launch services over nine years. The Air Force announced the winners Oct. 10.

OSP-4 is designed to accommodate small and medium payloads greater than 400 lbs. and providers have to be able to deliver these payloads to orbit within 12 to 24 months after receiving an order. The program is managed by the Air Force Space and Missile Systems Center’s Launch Enterprise Small Launch and Targets Division at Kirtland Air Force Base, New Mexico.

…The OSP-4 multi-vendor deal is known as a “multiple-award, indefinite-delivery/indefinite-quantity” contract. The eight companies will be awarded $50,000 as the contract’s minimum guarantee. Under [this arrangement], the Air Force will compete as many as 20 missions among the awardees.

The company list includes every operational rocket company (SpaceX, Northrop Grumann, ULA, Rocket Lab), as well as several in development (Xbow, Firefly, Aevum, Vox). It is interesting that several other developing rocket companies are not included (Blue Origin, Relativity, Vector). Vector has suspended operations because of financial issues, but Relativity and Blue Origin both appear to be moving forward with full financing. Meanwhile, I have until now never heard of Xbow, Aevum, and Vox. One wonders the reasoning behind their selection.

This selection is separate from the Air Force’s big rocket contracting process, where the military says it will very soon pick two companies to launch its big satellites for the next decade.

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FAA gives Rocket Lab an umbrella 5-year launch license

9:41 am

Capitalism in space: The FAA has awarded the smallsat launch company Rocket Lab a 5-year launch license, allowing it to streamline its regulatory process so that it can up its launch pace.

Rocket Lab has received a new five-year Launch Operator License from the Federal Aviation Administration, which grants it permission to do multiple launches of its Electron rocket from its LC-1 launch site in New Zealand without having to seek individual clearance for each one. While not the only limiting factor, this should help Rocket Lab increase the frequency of its launches from LC-1, servicing more customers more often for commercial small satellite customers.

While Rocket Lab has yet to achieve its goal of launches every two weeks, or even one per month, this license should at least remove one obstacle.

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Northrop Grumman buys back Pegasus rockets from Stratolaunch

9:35 am

Northrop Grumman announced this week that it has bought back from Stratolaunch the two Pegasus rockets that company had bought for the purpose of launch from its giant Roc airplane.

Phil Joyce, vice president of space launch programs at Northrop Grumman, said this week that the company is trying to sell the launches using the two remaining Pegasus XL rockets, and officials plan to keep the Pegasus rocket’s L-1011 carrier jet flying for at least five or 10 more years.

The airborne launch of NASA’s Ionospheric Connection Explorer, or ICON, scientific satellite Thursday night off Florida’s east coast is the final scheduled flight of a Pegasus XL rocket. Variants of the solid-fueled Pegasus rocket have flown on 43 satellite delivery missions since 1990.

“We actually purchased those back (from Stratolaunch),” Joyce said in an interview with Spaceflight Now. “So they’re in a very advanced state of integration, which means they’re available for a very rapid response launch. We could launch one of those in six months, the second one probably in eight (months).

This buy back tells us two things, both negative, about both companies. With Stratolaunch, it means they have abandoned entirely the idea of launching satellites using a combination of Roc and Pegasus. The reasons are unclear, but I would guess that they have either discovered the engineering didn’t work, or the economics made the combination unprofitable, being too expensive.

As for Pegasus, it appears the rocket has no further contracts, and has had so much trouble drumming up business that they have decided not to build more. Instead, they are going to try to get contracts for these already built Pegasuses, and are likely going to offer lower prices for them. Even if this works, it does appear that we are about to see the end of the Pegasus rocket.

Created in the early 1980s by Orbital Sciences (later Orbital ATK) as a cheaper alternative to the expensive big rockets of the time, Pegasus had a viable business model for years. Slowly over time however its launch price rose, until it was no longer very cheap. And when SpaceX and other new cheaper alternatives arrived in the past six years, the company, eventually absorbed by Northrop Grumman, was unable to remain competitive.

The irony here is that Northrop Grumman purchased Orbital ATK expressly to allow it to enter the launch market, using both Pegasus and Antares. With Pegasus gone, and Antares still failing to find any customers other than NASA, it doesn’t look like the merger is paying off well for the company.

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1st launch attempt tonight on Pegasus aborted; 2nd attempt a success

6:38 pm

Less than two minutes from launch mission control aborted the launch of the Pegasus rocket because of a communications problem between mission control and the flight crew on L-1011 aircraft.

This is after more than a year’s delay because of a difficult-to-pin-down problem with the Pegasus rocket itself.

They are presently working towards a second launch attempt tonight in about thirty minutes. You can follow this at the link above. Note that the NASA television feed is delayed about two minutes from the comment feed below. It is also filled with NASA’s incessant propaganda and pandering documentaries.

Pegasus has launched ICON and the first two stages have done their job. They are now coasting to the point where the third stage will fire. That coast is complete, the third stage has completed its job and ICON is in orbit.

This is Northrop Grumman’s second launch in 2019, so the leader rankings for the 2019 launch race remains unchanged:

19 China
17 Russia
10 SpaceX
6 Europe (Arianespace)

The U.S. however has regained its lead over China, 20 to 19, in the national rankings.

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Bridenstine’s visit to SpaceX a non-story

6:16 pm

Link here. Essentially he just reiterated his desire to have the private capsules being built by SpaceX and Boeing flying by early next year.

Essentially, the announcements in the last few days by Musk and Boeing about their upcoming testing and launch schedule for both Dragon and Starliner respectively took the steam out of his SpaceX visit.

In fact, I wonder what the politics were behind this. It is almost as if both companies wanted to take the steam out of his appearance here. Most intriguing.

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Ice suspected in both old and young lunar craters

1:46 pm

The uncertainty of science: New research of the craters where ice is suspected to exist on the Moon suggests that the ice is found in both young and old craters, which also suggests both that it comes from multiple sources and that some has been deposited more recently.

The majority of the reported ice deposits are found within large craters formed about 3.1 billion years or longer ago, the study found. Since the ice can’t be any older than the crater, that puts an upper bound on the age of the ice. Just because the crater is old doesn’t mean that the ice within it is also that old too, the researchers say, but in this case there’s reason to believe the ice is indeed old. The deposits have a patchy distribution across crater floors, which suggests that the ice has been battered by micrometeorite impacts and other debris over a long period of time.

If those reported ice deposits are indeed ancient, that could have significant implications in terms of exploration and potential resource utilization, the researchers say. “There have been models of bombardment through time showing that ice starts to concentrate with depth,” Deutsch said. “So if you have a surface layer that’s old, you’d expect more underneath.”

While the majority of ice was in the ancient craters, the researchers also found evidence for ice in smaller craters that, judging by their sharp, well-defined features, appear to be quite fresh. That suggests that some of the deposits on the south pole got there relatively recently. “That was a surprise,” Deutsch said. “There hadn’t really been any observations of ice in younger cold traps before.”

If there are indeed deposits of different ages, the researchers say, that suggests they may also have different sources. Older ice could have been sourced from water-bearing comets and asteroids impacting the surface, or through volcanic activity that drew water from deep within the Moon. But there aren’t many big water-bearing impactors around in recent times, and volcanism is thought to have ceased on the Moon over a billion years ago. So more recent ice deposits would require different sources — perhaps bombardment from pea-sized micrometeorites or implantation by solar wind.

I must emphasize that there is much uncertainty here. Most fundamental is the fact that at this moment we still really do not have a solid confirmation of the presence of ice in these permanently shadowed craters, only orbital data that suggests the presence of hydrogen, which scientists believe can only be there if it is locked in water molecules. This is not yet proven however.

It is intriguing however the evidence suggests ice in both young and old craters. This implies either some on-going process to put water there, or a series of specific but different events over time.

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Ice! Ice! Everywhere on Mars ice!

1:20 pm

Ice scarp in Milankovic Crater
Click for full image.

In January 2018 scientists announced the discovery of exposed ice in a number scarp cliff faces found in the high-mid-latitudes of Mars.

These scarps, which have so far been found in one southern 50-55 degree latitude strip and in one crater, Milankovic, at the same latitude in the north, are important because they are one of the first places on Mars in its lower latitudes where we have found ice actually exposed and visible, not buried like the many buried glaciers very near the surface found in the 30 to 60 degree northern and southern latitude bands.

Since that press announcement, scientists have been monitoring these sites for changes, as well as expanding their survey to see if they can locate more of these scarps.

Overview map

My previous posts on this subject were mostly focused on that southern strip near Hellas Basin, as shown on the map on the right. In reviewing the most recent image download from the high resolution camera on Mars Reconnaissance Orbiter (MRO), I noticed that the only new images of ice scarps were taken in the northern location, in Milankovic Crater, as indicated by the white dot north of Olympus Mons. The first image above shows the north-facing scarp of one of these images, cropped to focus in on the color section where, if you look close, you will see a strip of blue across the base of the scarp. That’s the ice layer, exposed as the scarp sublimates away over time from the north to the south.

over view of all MRO images taken so far in Milankovic Crater

This scarp, labeled #2 on the overview map of Milankovic Crater on the right, is located inside the crater’s eastern rim. The second image, posted below and labeled #1 on the overview map, shows a wider area of several ice scarps located on the inside of the crater’s southwestern rim.

The red boxes in the overview map indicate all the images taken by MRO inside this crater. If you go to the camera’s archive and focus in on Milankovic Crater at 54.5 degrees north latitude and 213.3 degrees longitude, you can then click on each red box to see the high resolution image. In practically every image along the crater’s inside rim can be found numerous scarps.
» Read more

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More “Free Hong Kong” protesters at NBA-Chinese exhibition games

9:30 am

Maybe we aren’t sheep: A group of protesters showed up at a Washington Wizards exhibition game yesterday against a Chinese basketball team with more “Free Hong Kong” signs, chanting the same throughout the game.

NBA officials however continue to kowtow to China’s demand to squelch these American protests, in America:

During the pregame singing of the Chinese national anthem, there were additional protests, with activists holding up signs and yelling, “Free Hong Kong.” One couple displaying a Tibetan flag left after being confronted by security. Yells of “Free Hong Kong” continued to ring out over the course of the game, as protesters migrated to different sections of the arena.

Security confiscated a “Free Hong Kong” sign from a group of protesters sporting the t-shirts. Later in the first quarter, the protesters displayed a smaller sign reading “Google Uyghurs,”—referring to Chinese Muslims incarcerated in state prison camps—which was also confiscated. [emphasis mine]

Meanwhile, the satirical website, the Babylon Bee, captures the stupidity and anti-Americanism of the NBA perfectly: NBA Now Requiring All Players To Stand For Chinese National Anthem, adding that “Anyone who doesn’t comply will be shot, a beloved Chinese custom that should further smooth things over with the authoritarian regime.”

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Mars Express looks at Martian river relic

9:18 am

Mars Express perspective view of Nirgal Vallis
Click for full image.

The Mars Express science team today released a mosaic produced by the orbiter’s high resolution camera of the 300 hundred mile long relic river valley Nirgal Vallis. The image to the right, reduced to post here, is the oblique view that was produced by computer using the camera’s stereo images.

This ancient valley system is named Nirgal Vallis, and was once filled with running water that spread across Mars. By exploring the characteristics of the surrounding craters, scientists estimate the system’s age to be between 3.5 and 4 billion years old.

The part of Nirgal Vallis captured in these images lies towards the western end of the river system, where it is slowly spreading out and dissipating; the eastern end is far less branched and more clearly defined as a single valley, and opens out into the large Uzboi Vallis – the suspected location of a large, ancient lake that has long since dried up.

Nirgal Vallis is a typical example of a feature known as an amphitheatre-headed valley. As the name suggests, rather than ending bluntly or sharply, the ends of these tributaries have the characteristic semi-circular, rounded shape of an Ancient Greek amphitheatre. Such valleys also typically have steep walls, smooth floors, and, if sliced through at a cross-section, adopt a ‘U’ shape. The valleys pictured here are about 200 m deep and 2 km wide, and their floors are covered in sandy dunes; the appearance of these dunes indicates that martian winds tend to blow roughly parallel to the valley walls.

Unlike the high resolution camera on Mars Reconnaissance Orbiter (MRO), which is for taking close-up images of specific surface features, Mars Express is producing a high resolution survey of the entire planet. Its camera does not have quite the same resolution, but as it is taking wider images that’s okay.

What is unfortunate is the European Space Agency’s policy for releasing those images. Unlike MRO, they do not make them all available to the public instantly. Instead, they periodically do press releases like today’s, highlighting a specific region or single large feature. As a result, Mars Express does not get the press it deserves.

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Buddy Ebsen – I’m nuts about you

6:01 pm

An evening pause: Ebsen is joined by Eleanor Powell, Jimmy Stewart, Una Merkel and Sid Silvers in this dance number from the 1936 film, Born to Dance.

Ebsen is remembered most for playing Jed Clampett in the tv comedy series, The Beverley Hillbillies, but he started out as a dancer in movies.

Hat tip Phill Oltmann.

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