Tag: science

Curiosity’s wheels holding up despite very mountainous and rocky terrain

12:01 pm

Wheel comparison on Curiosity after five months of rough travel
Click here and here for original images.

In the past half year the Mars rover Curiosity has moved into the mountainous foothills of Mount Sharp, crossing the roughest and rockiest terrain seen during its entire decade-long sojourn on the red planet.

Such terrain poses a serious threat to the rover’s already damaged wheels. Since early in the mission the science team had discovered that the wheels were more easily damaged by the Martian surface than had been expected when they were designed. Since then engineers have been very careful about picking the rover’s route, weaving it in and out to avoid the worst ground. They also take images of the wheels every few months to see if any additional damage has occurred.

The bottom image to the right is part of the most recent wheel survey, taken on January 11, 2022, the 3,353 sol the rover has been on Mars. The top image was taken about six and a half months earlier, in early June 2021. The numbers indicate the same tread areas in both pictures.

Based on this one comparison of part of one wheel, it appears that Curiosity’s wheels have not experienced much new damage, even though during the last half year it has climbed into the mountains and has been traveling continuously over rocks, stones, and boulders. Even now, as its sits in the stone valley beyond Gordon Notch, the ground everywhere is stark and forbidding. Yet, this wheel appears to show no new damage, suggesting that the rover’s full set of wheels are also holding up quite well considering its recent travels.

I focus on this particular wheel because it is the same wheel I have used for comparison since 2017, and thus provides a nice baseline for change. In fact, a comparison of today’s image with the one from 2017 shows that in four years there has been practically no change.

This data is quite encouraging, and bodes well for the mission, suggesting there is really nothing to stop Curiosity from climbing Mount Sharp for years to come.

Of course, this is a comparison of only one part of one of Curiosity’s six wheels. A review of the other wheels might suggest a different conclusion. I suspect however that the other wheels show the same thing. The engineers of Curiosity have done a miraculous job protecting the wheels these last four years.

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Astronomers detect interstellar object invading another distant solar system

9:56 am

Using the Atacama Large Millimeter/submillimeter Array (ALMA) and the Jansky Very Large Array (VLA) astronomers think they have detected for the first time an interstellar object that has invaded another distant solar system and disturbed material in its protoplanetary accretion disk.

From the paper’s abstract:

A point source ~4,700 au [astronomical unit, equal to about 100 million miles] from the binary has been discovered at both millimetre and centimetre wavelengths. It is located along the extension of a ~2,000 au streamer structure previously found in scattered light imaging, whose counterpart in dust and gas emission is also newly identified. Comparison with simulations shows signposts of a rare flyby event in action.

This data further confirms that interactions between interstellar objects occur with reasonably frequency, and can thus act to influence the formation of solar systems.

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Lucy update: Engineers testing solar panel fix on ground

3:44 pm

Engineers for the asteroid probe Lucy have begun doing ground tests on a duplicate solar array motor on Earth to see if their plan will work to get the partly deployed solar panel in space opened and latched.

If all goes right, they are aiming for an April attempt at deploying the panel.

In the meantime, the spacecraft continues its coast outwards, presently being about 30 million miles from Earth. Even though one solar array is not fully open, it appears the spacecraft is getting “ample power” for its present operations. It is unclear if this power — with one solar panel not fully opened — will be sufficient once the spacecraft reaches the region of Jupiter’s Trojan asteroids, much farther from Earth.

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Scientists discover that mid-sized dunes near Mars’ north pole move

11:41 am

Mars' North Pole

Scientists using images from Mars Reconnaissance Orbiter (MRO) collected over six Martian years (6.5 Earth years) have found that the mid-sized dunes dubbed mega-dunes near the north pole actually do move from year to year, unlike similar sized dunes elsewhere on the planet.

Megaripples on Mars are about 1 to 2 meters tall and have 5 to 40 meter spacing, where there size falls between ripples that are about 40 centimeters tall with 1 to 5 meter spacing and dunes that can reach hundreds of meters in height with spacing of 100 to 300 meters. Whereas the megaripples migration rates are slow in comparison (average of 0.13 meters per Earth year), some of the nearby ripples were found to migrate an average equivalent of 9.6 meters (32 feet) per year over just 22 days in northern summer – unprecedented rates for Mars. These high rates of sand movement help explain the megaripple activity.

Previously it was believed that such dunes were static planetwide, left over from a time when Mars’ atmosphere was thicker and could then move them more easily. This data however suggests that the winds produced over the north pole when the carbon dioxide in the atmosphere freezes in winter and sublimates back to a gas in summer are sufficient to shift these dunes in the surrounding giant Olympia Undae dune sea.

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InSight recovering from safe mode caused by Martian dust storm

9:34 am

Engineers have been able to regain contact with the Mars lander InSight after a Martian dust storm that put it in safe mode and cut off all communications for three days.

The mission’s team reestablished contact with InSight Jan. 10, finding that its power was holding steady and, while low, was unlikely to be draining the lander’s batteries. Drained batteries are believed to have caused the end of NASA’s Opportunity rover during an epic series of dust storms that blanketed the Red Planet in 2018.

The lander remains however in safe mode. The engineers hope they can resume limited science operations in about a week. Even before this even the limitations on InSight’s power generation due to dust on its solar panels had forced the science team to only gather data from the seismometer, and even then had to suspend all data gathering periodically.

Though the lander has survived this dust storm, it is presently unclear how much dust remains on its panels and thus how much power it can generate. If it only can generate enough power to keep the lander from freezing, but not do any science, it might be time to shut it down entirely.

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A butte on Mars

11:13 am

A butte on Mars
Click for full photograph.

Cool image time! Because the Martian geology inside the enclosed stone valley beyond Maria Gordon notch is so complex and exposed, the Curiosity science team is spending a lot of time there. As noted in their January 7th update:

[W]e are marvelling at the landscape in front of us, which is very diverse, both in the rover workspace and in the walls around us. It’s a feast for our stratigraphers (those who research the succession in which rocks were deposited and deduce the geologic history of the area from this). We are all looking forward to the story they will piece together when they’ve had a bit of time to think!

The image to the right, cropped and reduced to post here, was taken by the rover’s high resolution camera on December 18th, soon after it entered this stone valley and was part of scan covering both this butte as well as a nearby cliff. I had previously featured a close-up of the top of this butte and its incredible overhang on December 20, 2021. This image however shows the whole butte, which I estimate to be about 30 to 40 feet high is about 10 feet high.

Not only does the butte illustrate well the alien nature of this stark and barren Martian terrain, so does all the terrain surrounding it. The surface everywhere is nothing but pavement stones of all sizes. Once again, there is no life, something you practically never see on Earth.

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A tumbling 1,100-foot-wide asteroid

10:04 am

Nereus tumbling on December 10th close approach
Click for full image.

Using the Goldstone radio antenna in California, scientists have been able to take some of the highest resolution radar images of the 1,100-foot-wide asteroid Nereus during its close approach to Earth on December 10, 2021.

The montage to the right, cropped to post here, shows twelve images from the 39-image sequence, which can also be viewed as an animation here.

During the asteroid’s close approach, an image resolution of about 12.3 feet (3.75 meters) per pixel was possible, revealing surface features such as potential boulders and craters, plus ridges and other topography. Asteroid Nereus’ previous approach in 2002 was near enough to Earth to reveal the asteroid’s size and overall shape, but too distant to show surface features. The new observations will also help scientists better understand the asteroid’s shape and rotation while providing them new data to further refine its orbital path around the Sun.

The asteroid will not make a similar close-approach again until 2060.

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An oblong exoplanet?

9:46 am

The uncertainty of science: Astronomers, using a variety of space telescopes, have concluded that the shape of an exoplanet in the constellation Hercules is deformed by tidal forces imposed on it by its star.

On the planet WASP-103b, tides are much more extreme. The planet orbits its star in just one day and is deformed by the strong tidal forces so drastically that its appearance resembles a rugby ball. This is shown by a new study involving researchers from the Universities of Bern and Geneva as well as the National Centre of Competence in Research (NCCR) PlanetS, published today in the scientific journal Astronomy & Astrophysics.

The data also suggests that the nearby heat of its star has also caused the exoplanet to be inflated in size.

Need I add that this result is uncertain? It requires the scientists to make many assumptions based on only a tiny bit of data, something they admit to near the end of the press release, where the releases notes that this result needs to be confirmed by future observations.

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Strange land forms on the flanks of Mars’ Arsia Mons volcano

1:24 pm

Strange landforms on the flanks of Arsia Mons
Click for original image. Click here for the context camera image.

Cool image time! The center of the photo to the right was taken by the high resolution camera on Mars Reconnaissance Orbiter (MRO) on September 5, 2021. For posting here I have rotated, cropped, and reduced it, as well as added to each side the lower resolution context camera image of this region.

The ground slopes downhill to the north. Make sure you click on the image to see the full resolution version. In only a few miles the terrain changes from a mound with small knobs to a smooth area with few knobs to a chaotic area where the larger ridges and knobs are the dominant feature, with hollows and canyons in between.

You should also take a look at the full context camera image. Just to the southeast of the above picture is a large depression that looks like it has been filled with lava, with its western rim covered by that flow. Scientists have taken a lot of high resolution pictures of this depression with MRO, trying to decipher its geology.
» Read more

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Data from China’s Chang’e-5 lander detects very tiny amounts of water in lunar soil

9:29 am

The uncertainty of science: In a paper published yesterday, Chinese scientists revealed that data from an instrument on the Chang’e-5 lunar lander has detected evidence of very tiny amounts of water in lunar soil, amounts that confirm past data showing the Moon is very dry.

From China’s state-run press:

The study published on Saturday in the peer-reviewed journal Science Advances revealed that the lunar soil at the landing site contains less than 120 ppm water or 120g water per ton, and a light, vesicular rock carries 180 ppm, which are much drier than that on Earth. … The additional 60 ppm water in the rock may originate from the lunar interior, according to the researchers. [emphasis mine]

It is believed that most of this water is the result of hydrogen in the solar wind.

The paper can be found here.

Before we begin dancing in joy that the Moon is wet, reread the highlighted words. This data instead simply confirms past data that the Moon is very dry. In the paper itself, it is made very clear that this high water content, small as it is, was only detected in a single rock, with all of the surrounding terrain much much drier. From the paper:

The water contents are less than 30 ppm in most measured regolith spots except for [areas] D12 and D17, which may be due to the disturbance of the top layer of the more space-weathered/solar wind–implanted regolith by the lander exhaust and the subsequent sampling process. The unsampled areas of D12 and D17 may have been shielded by [a rock] from the lander exhaust and thus retain the top space-weathered layer that contains higher water content. We predict that higher water content may be found in surface regolith than that from the subsurface of the returned borehole samples if the original stratigraphy is preserved. The estimated water contents of the regolith in the landing area are in agreement with those measured in the Apollo regolith samples and the orbital observations.

In other words, the higher water content, still very dry, appears to only exist on the surface, which is why they suspect it is produced by the solar wind and is also very temporary.

Moreover, there are many uncertainties in this result. The detection might not even be water, but hydroxyl molecules.

What this study suggests is that the patches of suspected water that some orbiters think they have identified in low latitudes on the Moon may simply be these surface molecules left by the solar wind, and that if there is usable water on the Moon, it will only be found in those permanently shadowed craters at the poles, if there.

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Webb’s primary mirror successfully deployed

2:54 pm

Today engineers successfully completed the unfolding of the primary mirror on the James Webb Space Telescope.

The two wings of Webb’s primary mirror had been folded to fit inside the nose cone of an Arianespace Ariane 5 rocket prior to launch. After more than a week of other critical spacecraft deployments, the Webb team began remotely unfolding the hexagonal segments of the primary mirror, the largest ever launched into space. This was a multi-day process, with the first side deployed Jan. 7 and the second Jan. 8.

Mission Operations Center ground control at the Space Telescope Science Institute in Baltimore began deploying the second side panel of the mirror at 8:53 a.m. EST. Once it extended and latched into position at 1:17 p.m. EST, the team declared all major deployments successfully completed.

Next step over the next few months will be aligning the primary mirrors 18 segments with each other as well as the secondary mirror. First science images are expected during the summer, but do not be surprised if NASA releases some test images before then, should all be well and it obtains some eye candy.

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Debris in Perseverance core sample equipment

9:07 am

Debris in core sample carousel on Perseverance
Click for full image.

In attempting to store its sixth core sample on Mars last week, engineers discovered that Perseverance could not do so because several small pieces of the core sample had fallen into the equipment and prevented the drilling bit with the core from inserting itself completely into the sample storage carousel.

To understand the issue precisely, the engineers commanded Perseverance to first extract the bit from the carousel so they could get pictures of it.

The extraction took place yesterday (1/6) and data was downlinked early this morning. These most recent downlinked images confirm that inside the bit carousel there are a few pieces of pebble-sized debris. The team is confident that these are fragments of the cored rock that fell out of the sample tube at the time of Coring Bit Dropoff, and that they prevented the bit from seating completely in the bit carousel.

The photo to the right shows that material at the image’s bottom.

It appears this issue was anticipated when the rover was designed giving engineers a way to remove the debris. They plan to do so, but will proceed slowly as this will be the first time it will be attempted on Mars.

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A Martian cliff

1:30 pm

A strange Martian cliff
Click for full image.

Many features on Mars immediately make one think of the Grand Canyon and the stark dramatic geology of the American southwest. Today’s cool image on the right, cropped and reduced to post here, is a typical example. Photographed on September 7, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), it shows a dramatic cliff face that I estimate is about 3,000 feet high.

A closer look, however, almost always shows that this Martian terrain is not like the American southwest at all, but alien in its own way.

At the base of this abrupt cliff the terrain suddenly changes to a series of smooth downward fan-shaped flows. The cliff evokes rough boulders, avalanches, and chaotic erosion. The fans evoke a gentle and organized erosion of small particles like dust or sand. The two processes are completely different, and yet here the former is butted right up against the latter.

The fans also appear to flow out of hollows in the rough cliff, suggesting that somehow as the cliff erodes in chunks those chunks break into sand or dust, find the lowest points, and then flow downward like liquid.

How strange. How Martian. And how truly beautiful.

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Ice-filled crater on the Martian north polar ice cap

2:15 pm

Ice-filled crater on the Martian north pole ice cap
Click for full image.

Cool image time! The photo to the right, cropped to post here, was taken on September 18, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO) and shows a very distinct impact crater on top of the layered deposits of ice mixed with dirt that form the bottom layers as well as surround the visible north pole ice cap on Mars.

I purposely cropped the high resolution image so that the crater is off center to show the dark streaks that appear to blow away from the crater to the northwest, west, and southwest. This asymmetric pattern suggests the wind direction at this location generally flows to the west, but the pattern might also be caused by lighting effects. The location is at 82 degrees north latitude, and the Sun was only 31 degrees high when the picture was taken, causing long shadows. Also, in the full image, you can see a whole strip of similarly oriented streaks, suggesting that these are slope streaks descending a slope going downhill to the northwest.

The overview map below also provides important information about this location.
» Read more

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The very first observations of dying star before, during, and after it goes supernova

9:43 am

Astronomers have, for the very first time, observed in real time a dying red supergiant star prior to, during, and after it exploded as a supernova, thus destroying itself and collapsing into either a neutron star or a black hole.

This discovery is unprecedented because previous observations of the star prior to its explosion were discovered post-supernova, when astronomers went back and found it in archival footage. In this case the astronomers were studying the star before it exploded, and thus got a far more detailed look at its behavior.

Prior to this, all red supergiants observed before exploding were relatively quiescent: they showed no evidence of violent eruptions or luminous emission, as was observed prior to SN 2020tlf. However, this novel detection of bright radiation coming from a red supergiant in the final year before exploding suggests that at least some of these stars must undergo significant changes in their internal structure that then results in the tumultuous ejection of gas moments before they collapse.

This data will require the computer modelers and theorists to completely revise their computer models and theories for explaining the ignition of a supernova.

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Webb deploys heat radiator

8:57 am

Engineers today successfully deployed the heat radiator on the James Webb Space Telescope, allowing for unfolding of its 21-foot-diameter primary mirror over the next two days, the final step in the telescope’s deployment.

At about 8:48 a.m. EST, a specialized radiator assembly necessary for Webb’s science instruments to reach their required low and stable operating temperatures deployed successfully. The Aft Deployable Instrument Radiator, or ADIR, is a large, rectangular, 4 by 8-foot panel, consisting of high-purity aluminum subpanels covered in painted honeycomb cells to create an ultra-black surface. The ADIR, which swings away from the backside of the telescope like a trap door on hinges, is connected to the instruments via flexible straps made of high-purity aluminum foil. The radiator draws heat out of the instruments and dumps it overboard to the extreme cold background of deep space.

The whole operation took fifteen minutes.

If all goes well, by Saturday night (January 8th) engineers and scientists will have in their hands the world’s largest infrared telescope, and it will be operating in space. Actual scientific observations however will not begin immediately. It will still take several weeks for the telescope to cool down to the very cold temperatures it needs to see faint infrared objects, and then about five more months of additional testing to precisely align the mirrors while figuring out how the telescope itself operates in space.

We should expect the first raw and unaligned infrared images in about a month, with the first official observations released sometime in the very early summer.

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Webb engineers successfully deploy the telescope’s secondary mirror

2:50 pm

Engineers today confirmed that the secondary mirror for the James Webb Space Telescope has successfully deployed, its tripod structure unfolding and locking into place.

In addition the cover protecting the Mid-Infrared Instrument (MIRI) was successfully unlocked. The instrument’s science team did not open the cover yet because the telescope hasn’t yet cooled enough, its sun shield only in place for a day or so.

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Ingenuity’s next flight and the plans beyond

1:19 pm

Overview map
Click for interactive map.

In an update posted today written by Ingenuity pilot Martin Cacan, he outlined the engineering team’s goal for the Mars’ helicopter’s next flight, its nineteenth.

This flight, which will take place no earlier than Friday, Jan. 7, takes the scout vehicle out of the South Séítah basin, across the dividing ridge, and up onto the main plateau. The precise landing target for Flight 19 is near the landing site of Flight 8. Images taken during Flight 9 by the rotorcraft’s high-resolution Return-To-Earth (RTE) camera were used to select a safe landing zone.

…Spanning 207 feet (63 meters), this flight will last about 100 seconds at a groundspeed of 2.2 mph (1 meter per second) and altitude of 33 feet (10 meters) while taking 9 new RTE images. The final act of the flight is to turn nearly 180 degrees to flip the RTE camera to a forward-facing orientation for future flights toward the river delta. [emphasis mine]

The green line in the map to the right indicates the exact path, going about 207 feet to the northeast. The red dot marks the location of Perseverance on December 8, 2021, the last time the Perseverance science team updated their map showing the rover’s travels.

The highlighted words are the most important. Cacan also said this in his update:

The current mission goal is to reach the Jezero river delta to aid the Perseverance rover in path planning and scientific discovery.

Assuming the helicopter continues to function correctly, their next flights will apparently be aimed towards the delta. Whether that path will follow the planned route marked by the dashed yellow line, or cut straight across, is not clear. If the latter, that implies they have revised Perseverance’s planned route so that it also cuts straight across from about the point of Ingenuity’s next landing site.

More likely Cacan was not speaking literally, and that the route Ingenuity will take to the delta will follow the planned route, around that crater to the northeast.

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China takes the global lead in fusion research

9:47 am

In setting new records of temperature and running time in its own tokamak fusion experiment, China now leads the U.S. in the field of developing the technology for generating practical fusion energy.

[The U.S.] ITER’s target temperature is 150 million °C (270 million °F). China’s EAST facility, which is a key contributor to the ITER project, has hit this mark already, reaching 160 million °C (288 million °F) for 20 seconds, and holding 120 million °C (216 million °F) for 101 seconds in separate experiments announced last May.

The latest experiment tested the Chinese tokamak’s capability to endure extreme temperatures over longer periods, sustaining a temperature 2.6 times hotter than the Sun’s core for some 1,056 seconds, or 17 minutes and 36 seconds. Nobody’s ever sustained a high-temperature plasma for 1,000 seconds before, so this is an important milestone.

The development of this capability continues China’s effort to lead the world in all areas of research, led I think by the many high government officials in positions of great power after cutting their teeth as managers for China’s space effort. These individuals understand how to build big technology projects at the cutting edge of science, and are likely pushing for more such research in all fields, such as the experiments in fusion energy above.

As big government projects, however, the long term future of such work is very risky. Government projects like this might start out great, which describes China’s status today, but they always end up corrupt and hidebound, as seen in the Soviet Union and at NASA in the U.S.

Nonetheless, this success highlights China’s aggressive effort to lead the world in all things. We would be foolish to ignore this.

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Webb: Sun shield deployment completed

3:32 pm

Engineers today successfully completed the full deployment of the sun shield of the James Webb Space Telescope.

The unfolding and tensioning of the sunshield involved 139 of Webb’s 178 release mechanisms, 70 hinge assemblies, eight deployment motors, roughly 400 pulleys, and 90 individual cables totaling roughly one quarter of a mile in length. The team also paused deployment operations for a day to work on optimizing Webb’s power systems and tensioning motors, to ensure Webb was in prime condition before beginning the major work of sunshield tensioning.

The process took eight days, and was by far the most complex such remote deployment ever attempted by an unmanned spacecraft. The shield is now in place to shade Webb from sunlight and heat and thus allow it to observe very faint infrared objects billions of light years away.

Next comes the deployment of Webb’s secondary mirror, followed by the unfolding of its main mirror.

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Ice canyons at the Martian north pole

1:46 pm

Ice canyons at the Martian north pole
Click for full image.

Cool image time! The photo to the right, cropped and reduced to post here, was taken on July 24, 2021 by the high resolution camera of Mars Reconnaissance Orbiter (MRO) and shows one small portion of the edge of Mars’ north pole ice cap.

The many layers in that ice cap are clearly evident, with some darker because they were probably laid down at a time when the Martian atmosphere was more filled with volcanic ash. According to the presently accepted theory, the layers show the cyclical climate patterns of Mars, caused by the large shifts in its obliquity, or the tilt of the planet along its rotational axis, ranging from 11 to 60 degrees. Presently Mars is tilted 25 degrees, similar to Earth’s 23 degrees. The two extremes cause the planet’s water ice to shift back and forth from the mid-latitudes to the poles, causing the layers.

The height of this layered cliff face is probably about 1,500 feet, though that is a very rough estimate. Notice also that this image shows an ice canyon running from the left to the right and flowing into a much larger ice canyon to the right. The top cliff is probably about a third the height of the bottom cliff.

The overview map below shows gives the context, not only in place but also in time.
» Read more

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Webb deployment resumes, with continuing success

9:50 am

After a day delay to assess the telescope’s earlier operation in space, engineers yesterday resumed the deployment of the James Webb Space Telescope’s sun shield.

First they began tensioning the shield’s first of five layers, completing that operation in about five and a half hours.

Next the engineers proceeded to tighten layers two and three, completing that task in about three hours.

Today they have begun tightening the last two layers. A live stream of this slow and relatively unexciting process (as long as nothing goes wrong) is available from NASA here.

Based on what has been done so far, it appears that the deployment of the sun shield, considered the most challenging part of Webb’s deployment, is going to complete successfully. While the unfolding and deployment of the mirror still must be done, getting the sun shield deployed eliminates one of the great concerns that has kept both astronomers and engineers awake nights for decades.

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Sunspot update: The Sun blasts off!

10:16 am

Over the weekend NOAA posted its monthly update to its graph showing the long term trends in the Sun’s sunspot activity. As I do every month, I have posted that graph below, annotated to show the previous solar cycle predictions and thus provide context.

In December the Sun’s sunspot activity not only continued the pattern of the past two years — whereby sunspot activity has consistently exceeded the prediction of NOAA’s solar scientist panel — the amount of activity shot up like a rocket. December 2021 saw the most sunspots in a single month since September 2015, when the Sun was about a third of the way into its ramp down from the solar maximum in 2014.

» Read more

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The unfurling of Webb’s sun shield begins

5:18 pm

Engineers have begun the multi-day unfurling and deployment of the sun shield on the James Webb Space Telescope.

The first step is to deploy two booms on each side of the telescope that draw the shield itself outward.

The deployment of the first boom was held up several hours to give engineers time to make sure the protective covers had, in fact, rolled off to the side of the sunshade pallets as required.

“Switches that should have indicated that the cover rolled up did not trigger when they were supposed to,” NASA said in a blog post. “However, secondary and tertiary sources offered confirmation that it had.”

“The deployment of the five telescoping segments of the motor-driven mid-boom began around 1:30 p.m., and the arm extended smoothly until it reached full deployment,” NASA said.

Engineers then sent commands to deploy the second sunshade boom, which extended smoothly and locked in place at 10:13 p.m., finally giving Webb its iconic kite-like shape.

Next the shield has to be tightened in place, which will also separate and tighten in place the shield’s five layers. According to the schedule, the four layers will be tensioned today, with the fifth tomorrow.

The step-by-step deployment is outlined in detail here, and updates to the most recently completed step after it is finished.

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1st stage of Webb sun shield deployment completed

9:29 am

The deployment of the forward and aft pallets required to support the sun shield for the James Webb Space Telescope has apparently been successfully completed.

The link takes you to the website that outlines each step in Webb’s entire 30-day deployment sequence, and is updated to show you the next required step as the process continues. Though I have yet to see any official announcement, this page now shows that both pallets have successfully unfolded and that the next step is removal of the covers that have protected the sun shield membrene during assembly and launch.

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The badlands on the floor of Valles Marineris

1:03 pm

The badlands on the floor of Valles Marineris
Click for full image.

Cool image time! The recent discovery that there might be a near surface reservoir of ice on the floor the canyon Valles Marineris, near the Martian equator, immediately brought this location to the forefront as a possible site for establishing colonies. The weather will be less harsh than higher latitudes, the low elevation means a thicker atmosphere, and the terrain will be more appealing than the boring flat northern lowlands.

The picture to the right, cropped and reduced to post here, illustrates however the likely difficulties of landing and living on the floor of Valles Marineris. Taken on July 26, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), the photo shows just one small area of the floor of Ius Chasm, the western part of Valles Marineris and about 300 miles to the east of that water reserve.

In this one picture we can see trapped sand dunes in hollows, eroded depressions, mottled terrain resembling stucco, and innumerable cliffs and sinks and plateaus. For the first manned spacecraft to land on Mars, this is not a good first choice. Even later, when the first bases have been built, this terrain would still be forbidding for the early colonists to land in and traverse.

The overview map below shows exactly where this picture is relative to the rest of the Valles Marineris.
» Read more

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Finalists announced in the ’21 Illusion of the Year contest

9:59 am

The top ten finalists, including the first place winner, in the 2021 best optical illusion of the year contest have now been announced.

The annual illusion contest is run by the Neural Correlate Society, an organization devoted to promoting awareness of the science behind perception and cognition. For 17 years the annual contest has consistently delivered an assortment of compelling illusions, frequently underpinned by fascinating scientific principles.

This year’s winner, from UK scientist and magician Matt Pritchard, is a unique example of an anamorphic illusion. These are illusions that present a viewer with an image that appears distorted until it is looked at from a specific perspective.

I have embedded below a video showing Pritchard’s illusion, dubbed the Phantom Queen. If you go to the contest’s website you can see videos of all ten finalists, all of which are fun and quite remarkable in their ability to fool the eye.
» Read more

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Slope streaks in frozen lava flows on Mars

12:30 pm

Slope streaks on frozen lava
Click for full image.

Cool image time! The photo to the right, cropped and reduced to post here, was taken on June 5, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows a ridgeline at the base of the giant volcano Pavonis Mons, with slope streaks on ridge’s north and south sides.

Slope streaks are a mysterious phenomenon unique to Mars. While they resemble an avalanche, they do not change the topography of the surface at all. They appear to occur randomly year round, fading slowly with time. Also, while most are dark, scientists have also spotted bright slope streaks as well.

Slope streaks also only appear on surfaces covered with a layer of fine dust, something that is obviously the case in the cool image to the right. There is so much dust on the surface here that bedrock only appears at the top of the ridge, peeking out in only a few places.

The location of this image, as shown in the overview map below, adds some additional details.
» Read more

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Deployment of Webb’s critical sunshield has begun

9:03 am

The deployment of the complex sunshield for the James Webb Space Telescope has successfully begun, and if all continues as planned, will continue for the next five days.

Early this afternoon the Webb mission operations team concluded the deployment of the first of two structures that hold within them Webb’s most unpredictable and in many ways complicated component: the sunshield.

The structures – called the Forward and Aft Unitized Pallet Structures – contain the five carefully folded sunshield membranes, plus the cables, pulleys, and release mechanisms that make up Webb’s sunshield. The team completed the deployment of the forward pallet at approximately 1:21 p.m. EST, after beginning the entire process about four hours earlier. The team will now move on to the aft pallet deployment.

Over the next five days the aft pallet must be deployed, along with a tower assembly that will raise the telescope itself away from the sunshield to better keep Webb cold. After this the deployment of the many additional parts of the shield will take place, a process that is probably the most complex in-space spacecraft deployment ever.

It is good news that so far all is proceeding as planned, and gives hope that all will continue to do so.

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