An evening pause: In honor the various space related engineering daring-do today, let’s watch a modern fighter jet show off at an air show.
Hat tip Danae.
I have embedded the live stream of Falcon Heavy launch below the fold. It does not go live until just before launch, which is now scheduled for 6;35 pm (Eastern).
The live stream is now live. I will post updates below, so refresh your screen to see them.
This is not a routine SpaceX launch, where we have become nonchalant about the company’s ability to vertically land a first stage. They admit getting the core stage back will be challenging. They also admit that this is essentially a countdown of three rockets, so they are going to be very conservative. If anything pops up during countdown, they will scrub and try another day.
They have launched.
The side boosters have successfully separated.
The center core stage has successfully separated.
Re-entry burns for the two side boosters has been completed.
Re-entry burn on the core stage has been completed.
Both side boosters have landed.
The payload is in orbit.
The core stage has landed successfully on the drone ship.
Though the satellite has not yet been deployed, the rest of this mission is almost certainly going to go as planned, as it is essentially identical to a normal Falcon 9 launch. Update: payload successfully deployed!
Getting all three stages back is a notable achievement. They intend to recycle the two side cores and use them on the very next Falcon Heavy launch in June. The core stage will likely be reused as well but when has not yet been announced.
The leaders in the 2019 launch race:
4 SpaceX
4 China
4 Europe
3 Russia
The U.S. leads the pack 7 to 4 in the national rankings.
In the heavy lift launch race, SpaceX is by far in the lead in successful launches:
2 SpaceX
1 China
0 SLS (NASA)
I should add that I am being generous to include China’s Long March 5 in this heavy lift list. It really doesn’t qualify, but it remains the only other near competitor.
» Read more
Summary: Curiosity successfully drills into the clay unit. Yutu-2 continues its exploration on the far side of the Moon.
For the updates in 2018 go here. For a full list of updates before February 8, 2018, go here.
For the overall context of Curiosity’s travels, see my March 2016 post, Pinpointing Curiosity’s location in Gale Crater.
The news this week from Curiosity is that the rover has successfully drilled into the ground in the clay unit valley the rover is presently exploring betweent Vera Rubin Ridge and Mount Sharp’s higher slopes.
The image to the right shows is a close-up of that drill hole.
The rover’s drill chewed easily through the rock, unlike some of the tougher targets it faced nearby on Vera Rubin Ridge. It was so soft, in fact, that the drill didn’t need to use its percussive technique, which is helpful for snagging samples from harder rock. This was the mission’s first sample obtained using only rotation of the drill bit.
Since my last rover update on February 20, 2019, they have been traveling for several weeks to get to a spot where they can do this drilling. The clay unit seems very soft, and almost mudlike, which made finding a good surface to drill somewhat challenging. Most of the terrain seemed too soft to drill into. It almost would be better to have a scoop, as the Viking landers had. Curiosity doesn’t really have this however. It needs to use its drill, which really is a more efficient way to get down deeper into the ground anyway.
The map below shows their recent travels.
» Read more
An engine problem during landing has caused Beresheet to crash onto the lunar surface.
The image on the right was the last image beamed back by the spacecraft during the landing sequence. It looks down at the lunar surface from several thousand meters.
As Netanyahu immediately noted, “If at first you don’t succeed, you try again.”
This failure definitely slows down the effort to transition from government-controlled space exploration to a free effort by the independent citizenry of all nations. It does not stop it however. There are other private lunar missions already scheduled, and of course, there is the effort by SpaceX to build its own heavy-lift rocket to make interplanetary space travel affordable for all.
The next decade will see this effort blossom. Beresheet’s failure is an example of those first baby steps, when the ability to stand is uncertain, and sometimes results in a fall. But babies turn into adults. The future is bright indeed.
They have begun the live stream of Beresheet’s landing on the moon, with the arrival of Benjamin Netanyahu in the viewer’s gallery. It is in Hebrew, and will likely mostly involve watching people sitting at computer consoles, and then standing and cheering when the spacecraft lands.
However, I have embedded it below the fold for your viewing pleasure.
UPDATE: They are including English commentary.
» Read more
Capitalism in space: DARPA has chosen Vector Launch, Virgin Orbit, and a third unnamed company to compete for up to $10 million in prizes in its quick launch competition.
The Defense Advanced Research Projects Agency (DARPA) is giving $400,000 to each of three companies chosen to compete in the “DARPA Launch Challenge” to demonstrate rapid and responsive launch of small payloads. Tucson-based Vector Launch, Virgin Orbit, and a “stealth” startup will now have the opportunity to compete for prizes up to $10 million for successfully proving they can successfully launch twice in a row within a short timeframe from being provided mission parameters, DARPA told reporters here April 10.
First, I wonder why Rocket Lab was not picked. I suspect this is because it is already launching operational missions, and so does not need this developmental boost. Also, its rocket might not meet DARPA’s criteria. The launch systems of both Vector and Virgin Orbit are designed to allow them to quickly transport their rocket to any number of launch sites and go. Rocket Lab’s Electron appears to need a more established launchpad.
Second, I wonder what that third unnamed startup is. There are more than two dozen in development right now, but I can only think of one, Exos Aerospace, that has actually done any successful test flights, albeit suborbital. Whether its reusable SARGE suborbital rocket, being used to incrementally develop an orbital version, fits DARPA’s needs is not clear.
It could also very well be that DARPA has not actually chosen a third company, but has informed several that they can get that third slot, if they can achieve certain goals in a certain time frame. It could be that both DARPA and these companies would rather keep this private competition private. For the companies, they’d rather not advertise their failure to win it. For DARPA, the goal is to help, not hurt, the companies.
The new colonial movement: Despite two launch failures already this year as well as U.S. opposition, Iranian officials earlier this week said that they still have plans to launch three more times in 2019.
I have no idea how seriously we should take this claim. Iranian officials have made a number of claims in recent years that proved nothing by bombast. This might be that, or not.
Embedded below the fold in two parts.
» Read more
An evening pause: A song that looks back at September, from the cold fading days of December.
From The Fantasticks.
The new colonial movement: The privately-built Israeli lunar probe Beresheet has completed its last orbital maneuver before attempting a landing on the Moon tomorrow.
The elliptical orbit now has a low point of 9 to 10 miles above the lunar surface.
Capitalism in space: SpaceX has pushed its Falcon Heavy launch back to tomorrow, April 11, at 6:35 pm pm (eastern) tonight.
No reason yet on why. The live stream is embedded below the fold, and will be available here when the launch happens.
» Read more
Cool image time! The Lunar Reconnaissance Orbiter (LRO) science team today released a beautiful oblique image looking of the central peaks of Compton Crater, a far side crater with a floor that is fractured and is one of about 200 hundred such craters.
Today’s Featured Image highlights an floor-fractured crater (FFC) that could tell us much about the lunar crust. An asteroid or comet impact is thought to have excavated 146.6-kilometer-wide Compton crater about 3.85 billion years ago. Igneous intrusion or viscous relaxation — or perhaps both processes — subsequently produced branching fractures and small basalt plains within Compton crater. The latter are darker than their surroundings.
Unlike Copernicus Crater, the surface appears smooth. Go to the link and zoom in to see what I mean. All the fractures appear very large and filled in. Of course, that could be because of the image’s resolution, and that other images might show more details and pits.
I find the central peaks more intriguing, however. It appears that, following their formation they were hit by several bolides, one of which carved a gigantic deep hole into those peaks.
The European Space Agency today released the results of more than a year of observations from its Trace Gas Orbiter (TGO), among which were two significant findings.
First, the orbiter detected no methane in Mars’s atmosphere, contradicting recent results from both Curiosity and Mars Express.
The new results from TGO provide the most detailed global analysis yet, finding an upper limit of 0.05 ppbv, that is, 10–100 times less methane than all previous reported detections. The most precise detection limit of 0.012 ppbv was achieved at 3 km altitude. As an upper limit, 0.05 ppbv still corresponds to up to 500 tons of methane emitted over a 300 year predicted lifetime of the molecule when considering atmospheric destruction processes alone, but dispersed over the entire atmosphere, this is extremely low.
…“The TGO’s high-precision measurements seem to be at odds with previous detections; to reconcile the various datasets and match the fast transition from previously reported plumes to the apparently very low background levels, we need to find a method that efficiently destroys methane close to the surface of the planet.”
It appears they think the Curiosity and Mars Express detections were very localized and occurred close to the surface, where TGO could not detect it.
The second significant finding is indicated by the map below, showing a global map of subsurface water distribution on Mars. I have also posted below this map a global elevation map from Mars Reconnaissance Orbiter (MRO), as the similarities and differences are important.
» Read more
These two stories gleaned from yesterday’s House testimony by Attorney General William Barr at first glance might seem unrelated:
Of course these stories are related. The spying occurred in conjunction with the FBI’s effort to pin the fake Russian collusion accusation on Trump.
If a legitimate investigation occurs here, then a number of people will be facing jail time, for perjury, for abuse of power, for actually conspiring to overturn a legal election. Moreover, it appears the investigation might not be limited to actions by the FBI. According to Barr’s testimony today at a Senate hearing, multiple intelligence agencies are implicated.
While it is important that the top law enforcement in the United States publicly acknowledged that the Obama administration and its intelligence agencies surveilled its domestic political opponents during the heat of a presidential election, it is what [Barr] said next that was most startling: that the CIA and other federal agencies in addition to the FBI may have been involved. “I’m not talking about the FBI necessarily, but intelligence agencies more broadly,” he said.
This whole Russian-collusion scam was corrupt from the get-go. Its only benefit is that it has revealed the depth of corruption in the executive branch of the federal government, which tried to set itself up as an American Praetorian Guard, with the right to anoint its favored political leaders as president, rather than the voters.
More importantly, this investigation is going to find out how much the Democratic Party, and its leader at the time, Barack Obama, were involved in this scam. We know already that the Washington bureaucracy is highly partisan and Democratic. What we don’t know is if that unhealthy partisanship was weaponized by Obama to generate this scam.
Barr might very well find out.
It now appears that this week’s election in Israel has once again given Benjamin Netanyahu’s right wing coalition a strong enough majority to form the next Israeli government.
The right-wing bloc is predicted to have around 65 seats, compared with 55 for the centre and left, similar to the make up of the outgoing parliament.
Even before the election, all the smaller right-wing parties had pledged to back Netanyahu for prime minister, meaning his victory was always likely, Zalzberg said. “He demonstrated again his mastery of alliance-building among the different political tribes of Israel — he is unmatched in this.”
The problem for the strongest opposition party, dubbed Blue-and-White, is that though their leadership is moderate and pro-Israel, they cannot form a coalition with the religious parties in Israel, as Netanyahu can. Blue-and-White has forged alliances with the nation’s leftist parties, and Israel’s religious parties cannot participate in coalitions that include those parties.
What is interesting about this particular election is that it reduced the number of parties in the Knesset, Israel’s parliament. It appears the voters are now consolidating their support around fewer factions, which clarifies and simplifies the formation of the next government. It also suggests that Israelis feel more threatened, and are thus looking at larger issues in choosing the parties they support. They no longer feel the luxury of pushing side issues. Survival is becoming more paramount.
Using a network of ground-based radio telescopes astronomers today released the highest resolution radio image of black hole ever produced.
Before giving more details, I must correct every other news report, as well as all of the press releases about this image. It is not “The first image of a black hole!” as these releases are claiming breathlessly. Radio telescope arrays have taken such images in the past, but their resolution was poor, so the result was not very imagelike. Instead, it showed contour lines in a coarse manner. Moreover, the coarseness of the resolution prevented them from seeing the black hole’s shadow itself.
This image now produced has the highest resolution ever for such a radio image, but believe me, it is still coarse. Nonetheless, it represents a giant technological leap forward. The effort required upgrades to many of these telescopes, along with significantly improved computer analysis. Now for some details:
Black holes are extraordinary cosmic objects with enormous masses but extremely compact sizes. The presence of these objects affects their environment in extreme ways, warping spacetime and super-heating any surrounding material. “If immersed in a bright region, like a disc of glowing gas, we expect a black hole to create a dark region similar to a shadow — something predicted by Einstein’s general relativity that we’ve never seen before,” explained chair of the EHT Science Council Heino Falcke of Radboud University, the Netherlands. “This shadow, caused by the gravitational bending and capture of light by the event horizon, reveals a lot about the nature of these fascinating objects and allowed us to measure the enormous mass of M87’s black hole.”
The image reveals the black hole at the center of Messier 87, a massive galaxy in the nearby Virgo galaxy cluster. This black hole resides 55 million light-years from Earth and has a mass 6.5-billion times that of the Sun.
…Multiple calibration and imaging methods have revealed a ring-like structure with a dark central region — the black hole’s shadow — that persisted over multiple independent EHT observations. “Once we were sure we had imaged the shadow, we could compare our observations to extensive computer models that include the physics of warped space, superheated matter and strong magnetic fields. Many of the features of the observed image match our theoretical understanding surprisingly well,” remarks Paul T.P. Ho, EHT Board member and Director of the East Asian Observatory. “This makes us confident about the interpretation of our observations, including our estimation of the black hole’s mass.” [emphasis mine]
Note the highlighted words. To create this image they needed to combine data from numerous radio telescopes. Such work requires extensive calibration. The resulting image is manufactured, though without doubt it is manufactured from real radio data accumulated by multiple telescopes. Because those telescopes are separated by distance, however, there will always be gaps between their images, and it is in the calibration and imaging methods that the gaps are extrapolated away.
I don’t wish to imply that this image is fake. It is not. That the features persisted over multiple observations confirms that they were actually seeing the black hole’s shadow. It also confirms that these new interferometry techniques work.
However, much of the press hyperbole today is an effort to justify the many millions in tax dollars spent on this effort. The effort was absolutely worthwhile scientifically, but government bureaucracies always feel a need to oversell their work. That is partly what is happening here.
Many of my image posts about Mars have emphasized how slowly things change there. This post will highlight the exact opposite. When it comes to dust devils, it appears they can leave their trace frequently and often, and for some reason they seem to also favor specific locations.
Click for full image.
The string of images above are all of the same location in the southern highlands of Mars. All were taken by the high resolution camera of Mars Reconnaissance Orbiter (MRO) and can be found in the camera’s archive. I have cropped them to show the same approximate matching area. The first image in that strip above, shown at higher resolution to the right, was taken in June 2011 and titled “Possible Gully Features” by the MRO science team. This is not surprising, as the rounded hills in this image are actually the southwest rim of a large crater, and the slopes of craters have been found one of the best places to find the gullies where seasonal changes occur, all possibly caused by underground water.
From the title, it appears that the science team might have first hoped to spot either slope streaks or recurring slope lineae, the two most intriguing of these changing features. Instead, that 2011 image showed them a very eroded crater rim with a small scattering of dust devil tracks.
Click for full image.
This lack of gullies probably reduced interest in this location. It wasn’t until seven years later, in November 2018, that the MRO team decided to take another image of this location (the second image in the strip above and shown to the right at higher resolution). This time they found a significant increase in the number of dust devil tracks.
At this point the decision must have been made to take another image of this location a month later in December 2018. I assume the scientists were curious to see if they would spot any additional changes in that one month period. This was dust devil season, so the likelihood of seeing more tracks was not unreasonable.
How many tracks appeared, and whether they were concentrated in any particular place, such as the ridge lines, would help researchers better understand what generates them, which in turn will give them a better understanding of the Martian atmosphere.
The result was astonishing.
» Read more
The discoverers of 2007 OR10, a Kuiper Belt object discovered in 2007, are asking the public to vote on their three top choices for the object’s name.
You can vote here. The choices are Gonggong, Holle, and Vili.
The new colonial movement: The privately built lunar lander Beresheet has lowered its orbit in preparation for its planned lunar landing on April 11, now set for between 3 and 4 pm (Eastern).
It fired its engines on April 8 for 36 seconds, lowering its orbital low point to 131 miles.
The landing will be live streamed here.
Capitalism in space: In order to speed the development of its next generation commercial rocket, the Vulcan Centaur, ULA will fly Vulcan components as they are developed on its Atlas 5 rocket.
The first Vulcan technology to fly on Atlas 5 will be new payload fairings from Swiss supplier Ruag built using an “out-of-autoclave” production process that enables fairing halves to be produced as one piece, a process Ruag says lowers production time and costs. “The out-of-autoclave fairings, which are manufactured by Ruag, and now in the U.S. — they are in a factory next to ours in Decatur — that’s going to fly on Atlas 5 this year,” Louradour said.
Sometime in 2020 they will then fly an Atlas 5 launch using the solid rocket boosters Northrop Grumman is building for Vulcan.
This is not really news. When ULA announced their plans to build Vulcan in 2015, they said then that they intended to transition from Atlas 5 to Vulcan over time, slowly introducing components on Atlas 5 until it was entirely replaced.
Nonetheless, it shows that ULA is adopting some of the the same common sense development procedures used by SpaceX. By taking advantage of launches as they happen, they can speed development. And they need to do this in order to keep pace with SpaceX.
Isn’t competition wonderful?
The new colonial movement: The launch of India’s first lunar lander/rover, Chandrayaan-2, will likely be delayed again, from May until July.
This further delay is not confirmed by ISRO, India’s space agency. Nor is any clear reason given in the article above to explain this additional delay.
It would not surprise me however. The head of ISRO, K. Sivan, is a trained engineer. He has shown himself to be very willing to impose delays if he has any doubts about the success of the mission.
Capitalism in space: Rocket Lab announced this week that it is now offering satellite manufacture in addition to its launch services.
The “Photon” satellite platform was developed so that customers would not have to build their own satellite hardware. “Small satellite operators want to focus on providing data or services from space, but building satellite hardware is a significant barrier to achieving this,” said Rocket Lab founder and chief executive Peter Beck, in a statement. “The time, resources and expertise required to build hardware can draw small satellite operators away from their core purpose, delaying their path to orbit and revenue. As the turn-key solution for complete small satellite missions, Rocket Lab brings space within easy reach. We enable our customers to focus on their payload and mission – we look after the rest.”
The satellites are designed for a range of Low Earth Orbit missions including technology demonstrations, risk reduction pathfinders, constellations, and hosted payloads, the company said in a statement.
This is not surprising. With their Electron rocket now operational, and about to begin monthly launches, they have the profits and margin to offer a complete launch package to smallsat customers.
Capitalism in space: SpaceX’s second launch of its Falcon Heavy rocket, the world’s most powerful, has now been rescheduled for 6:36 pm (eastern) on April 10.
This will definitely be worth watching. (I will post the SpaceX live stream link when it goes up.) If all goes well, the three first stage boosters will all land themselves after first stage separation, with two coming in simultaneously on neighboring landing pads in Florida, with the third landing very shortly thereafter on its landing barge in the Atlantic.
A success here will also give the Falcon Heavy two successful launches, two more than SLS (with none), and one more than China’s Long March 5, which is half as powerful but has not launched in almost two years after it failed on its second launch attempt.
The comparison with SLS is more pertinent. Tomorrow’s launch, if successful, will once again demonstrate the complete failure of NASA’s SLS rocket. This government boondoggle has been in development since 2004 in various iterations, for a cost that is likely to exceed $25 billion, fifty times more than it cost SpaceX to develop and make operational the Falcon Heavy. SLS’s first launch, originally scheduled for 2017, is now set to launch in June 2020, but is also more likely to be delayed months, if not more. Beyond that it will likely be more years before its second launch.
Falcon Heavy meanwhile is scheduled to do its third launch in mere months, should tomorrow go off without a hitch. It also has contracts for at least seven future launches. Nor would I be surprised if it completes most of these launches before SLS flies for the first time.
At some point the dimwits in Washington will I hope finally notice the contrast, and stop wasting money on SLS. Give it time, however. They are not very smart, and aren’t really interested in the needs of the American nation.
An evening pause: I like the commentary about this song at the youtube webpage. “Although it has been described as a protest song, it poses a series of rhetorical questions about peace, war and freedom. The refrain “The answer, my friend, is blowin’ in the wind” [is] … impenetrably ambiguous: either the answer is so obvious it is right in your face, or the answer is as intangible as the wind.
In this sense, Bob Dylan’s song really does transcend the 1960s, as does much of his work.
Hat tip John Vernoski.
New data from ground-based telescopes show that the atmosphere of Jupiter quickly changes due to changes in the solar wind, and that these changes descend deeper into the atmosphere than expected.
Auroras at Earth’s poles (known as the aurora borealis at the North Pole and aurora australis at the South Pole) occur when the energetic particles blown out from the Sun (the solar wind) interact with and heat up the gases in the upper atmosphere. The same thing happens at Jupiter, but the new observations show the heating goes two or three times deeper down into its atmosphere than on Earth, into the lower level of Jupiter’s upper atmosphere, or stratosphere.
…”What is startling about the results is that we were able to associate for the first time the variations in solar wind and the response in the stratosphere – and that the response to these variations is so quick for such a large area,” said JPL’s Glenn Orton, co-author and part of the observing team.
Within a day of the solar wind hitting Jupiter, the chemistry in its atmosphere changed and its temperature rose, the team found. An infrared image captured during their observing campaign in January, February and May of 2017 clearly shows hot spots near the poles, where Jupiter’s auroras are.
Considering Jupiter’s size, for these effects to extend so quickly really is startling.
Click for full image.
Honestly, don’t ask me. I didn’t come up with the name. I found the image on the right, cropped and reduced to post here, as part of the April image dump from the high resolution camera of Mars Reconnaissance Orbiter. The uncaptioned release dubbed this “Thumbprint Terrain in Northern Mid-Latitudes,” and it is obvious to see why. The cropped image on the right focuses in on the oval white mounds that really do look like some giant child was touching a soft damp muddy surface randomly with his fingers, leaving behind raised fingerprints as the mud stuck to his fingers as he pulled them away.
Each white area seems to have a crater. I suspect these are not impact craters, but possibly mud volcanoes, as each is at the top of a mound. My hypothesis is further strengthened by the location, which is deep within the low northern plains of Mars, a place where some scientists believe an intermittent ocean once existed. These mounds could have easily formed at that ocean’s floor, or thereafter when the land here was drying out.
On the other hand, these could be from impact. Maybe they are scattered ejecta from a larger impact, landing here in a group on a wet muddy surface. The impacts might have concentrated the material around the crater, making it more resistant to erosion, which is why the craters now stand above the floor of the plain.
On the third hand, all these theories could be wrong. Have any of your own?
They’re coming for you next: A coalition of more than forty leftwing organizations, most with strong ties to the Democratic Party, have written a letter demanding that corporations blacklist nearly thirty former Trump officials.
A coalition of left-wing groups is targeting nearly 30 current and former Trump-administration officials with a corporate blacklist meant to prevent the officials from obtaining jobs in the private sector.
…The letter urges the CEOs to not hire or contract any of the officials and to bar them from sitting on corporate boards.
Gee, I seem to remember how the left for decades condemned the concept of a blacklist. Of course, that was when the blacklist was aimed at them. I guess blacklists for the left are perfectly all right, as long as they only act to destroy the lives of those on the right.
To be blunt, a blacklist for political reasons is always wrong. While it is perfectly legitimate for certain companies to not hire certain people because of their political beliefs, especially if those beliefs could distract from the company’s business, it is never acceptable for society to demand that no one hire them, ever, which is exactly what what these leftist organizations are doing.
This is only the beginning. The left today smells blood, and wants it from all their opponents. It will not stop until someone stops it, forcefully. The best way this could happen would be by a smashing defeat at the polls. If that fails, then there will be violence, as eventually the people the fascist left wishes to oppress will stand up and fight.
Even though we are now deep into the beginning of what might become the first grand minimum in sunspot activity since the invention of the telescope, that does not mean the Sun has as yet stopped producing sunspots. Yesterday NOAA released its the monthly update of its tracking of the solar cycle, adding sunspot activity for March 2019 to its graph. Below is that graph, annotated by me to give it some context.
It shows the Sun with a slight burst in activity in March, suggesting that though we are now in the solar minimum that minimum still has the ability to produce sunspots.
At the same time, for me to say that we might be heading to a grand minimum, a time period lasting many decades where no sunspots are visible and the sunspot cycle essentially ceases, is not click bait or hyperbole. It is instead based on what I now think the solar science community is thinking, based on this very graph.
The graph above has been modified to show the predictions of the solar science community for the previous solar maximum. The green curves show the community’s two original predictions from April 2007, with half the scientists predicting a very strong maximum and half predicting a weak one. The red curve is their revised May 2009 prediction, extended in November 2018 four years into the future.
For past half dozen or so cycles the solar science community had issued its prediction for the upcoming solar maximum at about this stage in the overall cycle, during the final ramp down to minimum when it was clear that the Sun had entered that minimum.
This cycle’s prediction however has not yet happened, and in fact appears to be late. In fact, the extension of the May 2009 red curve that was made in November 2018 might very well be the only prediction we see. That extension is shown by the differences between the green 2007 prediction and the red 2009 prediction in the graph. Before November 2018 both curves ended at the same place, the end of 2018.
The extension of that red curve is important. As I noted in my December 2018 sunspot update,
» Read more
Embedded below the fold in two parts.
» Read more
