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

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.

Webb deploys heat radiator

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.

Webb engineers successfully deploy the telescope’s secondary mirror

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.

Ingenuity’s next flight and the plans beyond

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.

China takes the global lead in fusion research

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.

Webb: Sun shield deployment completed

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.

Ice canyons at the Martian north pole

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

Webb deployment resumes, with continuing success

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.

Sunspot update: The Sun blasts off!

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

The unfurling of Webb’s sun shield begins

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.

1st stage of Webb sun shield deployment completed

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.

The badlands on the floor of Valles Marineris

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

Finalists announced in the ’21 Illusion of the Year contest

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

Slope streaks in frozen lava flows on Mars

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

Deployment of Webb’s critical sunshield has begun

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.

Webb: Course correction burn and main antenna deployment both a success

Over the weekend engineers for the James Webb Space Telescope successfully completed a course correction burn that put the telescope on route to is planned location a million miles from Earth.

They also successfully deployed the telescope’s main antenna.

Other steps completed on Webb’s first full day in space included the switch-on of temperature sensors and strain gauges on the telescope, used for monitoring Webb’s thermal and structural parameters, NASA said. The antenna release and first mid-course correction burn set the stage for the next step of Webb’s post-launch commissioning — the deployment and tensioning of the observatory’s tennis court-sized sunshield.

These next steps are likely the most risky part of the telescope’s deployment, as it involves the most moving parts and is the most complex. While similar such unfoldings have been done successfully many times before, they have also been the very prone to failure.

The sunshield must work however for Webb to operate. As an infrared telescope, it essentially detects heat, and if it is not well shielded from sunlight its images will be fogged.

The deployment is presently set to begin tomorrow.

Webb successfully launched

Early this morning an Ariane 5 rocket successfully launched the James Webb Space Telescope from French Guiana.

The key moment that indicated the launch was success was, after Webb was deployed from the rocket’s upper stage, its solar panels deployed and the telescope began receiving power from them.

The launch itself was something that has been done by the Ariane 5 rocket many many times, without failure. Now comes the part of this operation that has never been done before.

Now “30 days of terror” begin, as JWST starts its career in space. First, it will take the space telescope 30 days to reach the start of its halo orbit at L2. On its way, the telescope must unfurl its 18 gold-plated beryllium mirror segments using 132 actuators. It will also have to deploy its five-layer, origami sunshield and cool down to below 50K (-223°C or -370°F) to begin the start of science operations in 2022.

NASA has a webpage that shows the step-by-step deployment, and allows you to see the status at any time during the next 30 days.

After almost twenty years of development and a budget that went 20x over its original estimate, let’s us all hope that Webb deploys properly and begins collecting data as intended. If it does, it will allow astronomers to make ground-breaking discoveries, and we shall gain a better idea of what lies hidden behind that black sky that surrounds us.

As for the 2021 launch race, this is the updated leader board:

49 China
31 SpaceX
22 Russia
7 Europe (Arianespace)

China will likely be the winner in the national rankings, 49 to 48 over the U.S. This was the 130th successful launch in 2021, only the second time in the history of space exploration that the world reached that number of launches in a single year.

December 22, 2021 Zimmerman/Pratt on Texas podcast

Robert Pratt has now made available a 20 minute podcast I did with him this week. You can listen or download it here. From the podcast announcement:

New Texan Elon Musk has the ear of many of the younger techies and he is giving them good lessons on government policy. Also, Robert Zimmerman of BehindtheBlack.com joins us for a space industry updated including comment on the James Webb Telescope set for launch on Friday; Blue Origin’s orbital engine delays, and; much on Elon Musk’s SpaceX including developments at the firm’s Texas launch facility in Cameron County.

Astronomers detect 70 to 170 free floating exoplanets

The uncertainty of science: Astronomers today announced that they think they have detected from 70 to 170 exoplanets in a nearby star-forming region that are apparently free-floating, unattached to any star or solar system.

The astronomers also combined the vast number of images available in public astronomical archives with the new deep wide-field observations obtained with the best infrared and optical telescopes on the ground and in space. Using over 80,000 wide-field images adding up to around 100 terabytes and spanning 20 years, they identified at least 70, and up to as many as 170 of these Jupiter-sized planets, as members of the Upper Scorpius association among the background stars and galaxies.

If confirmed, this discovery more than doubles the number of free-floating planets known.

The discovery was made by first using the motion of the stars to pinpoint which ones belonged to the Upper Scorpius star-forming region. The astronomers then compared this data with past archival telescopic images.

Though intriguing, a great deal of skepticism of this discovery is required. The press release is very vague about some points. For example, no explanation is given on how they measured the mass of these objects to determine they were Jupiter-sized.

The barren rocky terrain in the mountains of Gale Crater

Curiosity's view looking south towards Mt Sharp, Sol 3333, December 21, 2021
Click for full resolution image. Original photos can be found here, here, here, here, and here.

Overview map
Click for interactive map.

Cool image time! Curiosity yesterday used its navigation cameras to take a panorama of the view inside Maria Gordon Notch. The mosaic above, created from five images taken by the right navigation camera, shows the view looking south and uphill towards Mount Sharp. The heights of the nearest four hills are likely ranging from 30 to 100 feet.

The red dotted line indicates the planned route out of Gordon Notch and up onto the Greenheugh Pediment. If you click on the panorama to look at the full resolution version, you will see that the exit route looks extemely rough, possibly too rough for Curiosity to handle. How the science team handles this issue will be fascinating to watch in the coming weeks.

The map to the right gives us an overview. The white line is Curiosity’s actual travels. The red dotted line marks the planned route. The yellow lines indicate the area covered by the panorama above.

The most striking feature of this Martian terrain is its stark barrenness. All one can see in all directions are rocks and inanimate geology. There is no life, none at all. On Earth it is practically impossible to find any mountainous spot as barren as this, even in the most extreme and hostile environments.

As I’ve said before, Mars is strange, Mars is wonderful, and above all, Mars is alien.

ESA delays Webb launch one day due to weather

The European Space Agency (ESA) announced late yesterday that, due to “adverse weather conditions” in French Guiana, it has delayed the launch of the James Webb Space Telescope on an Ariane 5 rocket one day to December 25th.

The announcement also stated that the final launch readiness review also approved the launch, though no update has yet been issued on the ground control communications problem that had caused a two day delay last week.

Meanwhile, this story and its headline encapsulates the terror I think many astronomers presently feel about this telescope:

Why Astronomers Are “Crying and Throwing Up Everywhere” Over the Upcoming Telescope Launch

The sense is one of helpless panic among astronomers who want to use Webb. They know it will do really cutting edge science, but they also know that many things can go wrong, and the history of the telescope (ten years late and 20x overbudget) will likely make replacing it impossible.

And many things can go wrong. Below is NASA’s video showing the telescope’s complex unfolding, step-by-step, after launch.
» Read more

Curiosity: Through the notch and looking back

Looking back at the entrance to Gordon Notch
Click for full image.

The Mars rover Curiosity has now climbed up into Maria Gordon Notch. The image to the right, reduced to post here, was taken by the rover’s left navigation camera and looks back at the entrance to the notch, with the floor and rim of Gale Crater beyond. The crater floor is about 1,700 feet below and the rim is about 30 miles away.

The red dotted line indicates the path Curiosity took after entering the notch, traveling about 80 feet to the southeast. The rover will continue south inside the notch for another 800 feet or so and then turn west, climbing out of the notch and up onto the Greenheugh Pediment and continuing west until it gets to the base of Gediz Vallis Ridge, a ridge that had been in prominent view about a year ago when the rover was north of it but lower down the mountain. (See the panorama in this February 2021 post.)

Below is another picture from a day earlier, this time taken by the rover’s high resolution mast camera. I think it looks up at the top of the western cliff, but now looks at that cliff after having gone past it slightly.
» Read more

Webb launch confirmed for December 24, 2021

Ten years late and twenty times over budget the European Space Agency (ESA) yesterday confirmed that the launch of NASA’s infrared James Webb Space Telescope is now scheduled for December 24, 2021.

The ESA announcement is only a couple of sentences long, and does not mention if engineers had solved the intermittent ground communications issue with the telescope. Further tweets from ESA and NASA also said nothing about the communication issue.

A final readiness review is set for December 21st where a final launch decision will be made.

Scientists discover underground reservoir of hydrogen, likely ice, near Martian equator

Detection of underground hydrogen in Valles Marineris
Click for full image.

In what could be a very significant discovery, scientists using Europe’s Trace Gas Orbiter (TGO) have discovered a surprisingly large underground reservoir of hydrogen, likely ice, near Martian equator and inside the solar system’s largest known canyon, Valles Marineris.

The map to the right, reduced to post here, provides all the important data. From its caption:

The coloured scale at the bottom of the frame shows the amount of ‘water-equivalent hydrogen’ (WEH) by weight (wt%). As reflected on these scales, the purple contours in the centre of this figure show the most water-rich region. In the area marked with a ‘C’, up to 40% of the near-surface material appears to be composed of water (by weight). The area marked ‘C’ is about the size of the Netherlands and overlaps with the deep valleys of Candor Chaos, part of the canyon system considered promising in our hunt for water on Mars.

What the caption does not note is the latitude of this hydrogen, about 3 to 10 degrees south latitude. Assuming the hydrogen represents underground ice, this would be the first detection on Mars below 30 degrees latitude, and the very first in the equatorial regions. Data from orbit has suggested that Mars has a lot of water ice, found near the surface more and more as you move into higher latitudes above 30 degrees and making Mars much like Antarctica. Almost no ice however had until now been detected below 30 degrees latitude. As the European Space Agency’s press release noted,
» Read more

Visible clean water ice on Mars

Crater with ice scarp
Click for full image.

Cool image time! The photo to the right, cropped and reduced to post here, is today’s picture of the day for the high resolution camera on Mars Reconnaissance Orbiter (MRO). Taken on September 13, 2021, it shows an exposed scarp on the southern inner wall of a small 800-foot-wide crater.

What makes that scarp intriguing is its blue color. As noted by Shane Byrne of the Lunar and Planetary Lab University of Arizona, who wrote the caption:

This north-facing cliff appears to expose icy material that’s similar to other pole-facing scarps showing buried ice elsewhere on the planet. These cliffs give us a cut-away view of the buried ice in that location and can help answer questions about what the Martian climate was like when this ice formed.

The crater itself sits inside a much larger crater, as shown in the wider picture below.
» Read more

Scientists confirm Parker entered Sun’s corona in April 2021

Scientists yesterday announced that the Parker Solar Probe successfully entered the Sun’s corona for the first time during its April 2021 close fly-by.

More information here, including some excellent short movies made from images created by Parker’s instruments.

The top edge of the corona is dubbed the Alfvén surface, and Parker’s passage across that boundary three different times during the April ’21 fly-by revealed it to be a sharp boundary that also has a great deal of topography. From the second link:

The first time Parker passed the Alfvén surface was the longest; it flew through the atmosphere for about five hours. Even as it continued flying toward the Sun, though, it popped back out, only to submerge again more deeply when it was at its closest approach — but briefly, that time exiting after just half an hour. Then, on its way outward, the spacecraft once again skimmed beneath the surface for a few hours.

“[The Alfvén surface] has to be wrinkly,” Kasper says. “It’s not fuzzy — it’s well-defined while we’re under it — but the surface has some structure to it.” So while the probe sees a smooth change in conditions while crossing the boundary, where the boundary is can change. The reason for this wrinkly surface is still an open question, though the researchers suspect the crossing over a pseudostreamer lower in the corona pushed the boundary out to enable the first crossing.

What’s clear is that inside the Sun’s atmosphere, conditions are different than just outside. Parker saw plasma waves moving back and forth instead of flowing outward. That difference was visible not just to the SWEAP and FIELDS instruments, which measure particles and electric and magnetic fields, respectively, but also to the probe’s WISPR imager.

The Parker science team also indicated that the preliminary data from the probe’s next two fly-bys — the most recent in November that was the closest yet — suggest it passed through the corona then as well.

One of the biggest unsolved mysteries about the Sun’s corona is that it appears to have a temperature in the millions of degrees, far hotter than the Sun’s surface below, something that is counter-intuitive. The expectation was that the atmosphere would be cooler than the surface. Finding out why the corona is hotter is one of the main science goals of Parker. It appears the probe is finally gathering data that might help solve that mystery.

Webb launch delayed two days because of ground equipment issue

After engineers at Arianespace’s French Guiana launch facility found an intermittent issue with ground equipment related to the Ariane 5 rocket launching the James Webb Space Telescope, it was decided to delay the launch two days to make sure the problem was resolved.

n a brief statement, NASA wrote on its website late Tuesday that the Webb team is “working a communications issue between the observatory and the launch vehicle system.”

Thomas Zurbuchen, associate administrator for NASA’s science mission directorate, said Tuesday that engineers found an “interface problem” in a system that communicates with Webb while it’s on top of the Ariane 5 rocket. “The way to think about it is it’s a ground support equipment thing,” Zurbuchen said Tuesday night in an interview with Spaceflight Now. “Basically, the data cables are dropping some frames.”

Technicians inside the Ariane 5 rocket’s final assembly building in Kourou have tried to diagnose the problem, but so far, haven’t been able to resolve it.

The December 24th target day date remains tentative, and could slip to December 25th, or even later, depending on how successful engineers are at fixing the issue.

99.9% of all mass at center of Milky Way is found in central black hole

New measurements of the orbits of several stars circling the Milky Way’s central supermassive black hole, Sagittarius A* (pronounced A-star), have confirmed that 99.9% of all mass at the galaxy’s center is concentrated in that black hole.

Astronomers have measured more precisely than ever before the position and velocity of four stars in the immediate vicinity of the supermassive black hole that lurks at the center of the Milky Way, known as Sagittarius A* (Sgr A*) [1]. These stars — called S2, S29, S38, and S55 — were found to be moving in a way that shows that the mass in the center of the Milky Way is almost entirely due to the Sgr A* black hole, leaving very little room for anything else.

The measurements, which further refine the mass of Sagittarius A* as 4.3 million times the mass of the Sun, show that very little of this mass is found in the surrounding space as gas or dark matter. It is all in the black hole, which might also help explain why the Milky Way’s central black hole is so quiescent. It has very little gas or other stars to feed it and thus produce emissions.

Conflict in Hubble constant continues to confound astronomers

The uncertainty of science: In reviewing their measurements of the Hubble constant using a variety of proxy distance tools, such as distant supernovae, astronomers recently announced that their numbers must be right, even though those numbers do not match the Hubble constant measured using completely different tools.

Most measurements of the current acceleration of the universe (called the Hubble constant, or H0) based on stars and other objects relatively close to Earth give a rate of 73 km/s/Mpc. These are referred to as “late-time” measurements [the same as confirmed by the astronomers in the above report]. On the other hand, early-time measurements, which are based on the cosmic microwave background emitted just 380,000 years after the Big Bang, give a smaller rate of 68 km/s/Mpc.

They can’t both be right. Either something is wrong with the standard cosmological model for our universe’s evolution, upon which the early-time measurements rest, or something is wrong with the way scientists are working with late-time observations.

The astronomers are now claiming that their late-time observations must be right, which really means there is either something about the present theories about the Big Bang that are fundamentally wrong and that our understanding of early cosmology is very incomplete, or the measurements by everyone are faulty.

Based on the number of assumptions used with both measurements, it is not surprising the results don’t match. Some of those assumptions are certainly wrong, but to correct the error will require a lot more data that will only become available when astronomers have much bigger telescopes of all kinds, in space and above the atmosphere. Their present tools on Earth are insufficient for untangling this mystery.

Curiosity looks back at its entire journey

Curiosity looking back across Gale Crater
Click for high resolution mosaic. Original images here, here, here, and here.

Wide overview map
Click for interactive map.

Cool image time! The mosaic above was created from four photos taken by Curiosity’s left navigation camera on December 12, 2021, just after the rover had moved into Maria Gordon Notch. The view is to the north, looking back at the rover’s journey climbing up the floor of Gale Crater into the foothills of Mount Sharp. The rim of Gale Crater can be seen about 25 to 30 miles away.

The cliff in shadow on the left is about 40 feet high. The cliff in sunlight on the right is between 30 to 60 feet high, depending on where you measure.

The overview map to the right shows Curiosity’s entire journey, with the yellow lines indicating the approximate area covered by the mosaic above. All told the rover has climbed about 1,700 feet since it landed. While much of the rover’s route is blocked from our view by the cliffs on left, the nearest sand dune sea in the center of the mosaic is the one that the rover circled around from January 2021 to June 2021.
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