Tag: sun

Two flybys of Venus set by two spacecraft on August 9th and 10th

8:54 am

Two European planetary probes, one launched to study the inner solar enviroment and the second to study Mercury, are going to fly past Venus only 33 hours apart on August 9th and 10th.

Solar Orbiter, a partnership between ESA and NASA, will fly by Venus on 9 August with a closest approach of 7995 km at 04:42 UTC. Throughout its mission it makes repeated gravity assist flybys of Venus to get closer to the Sun, and to change its orbital inclination, boosting it out of the ecliptic plane, to get the best – and first – views of the Sun’s poles.

BepiColombo, a partnership between ESA and JAXA, will fly by Venus at 13:48 UTC on 10 August at an altitude of just 550 km. BepiColombo is on its way to the mysterious innermost planet of the solar system, Mercury. It needs flybys of Earth, Venus and Mercury itself, together with the spacecraft’s solar electric propulsion system, to help steer into Mercury orbit against the immense gravitational pull of the Sun.

The two spacecraft will zip past a different side of Venus. For a variety of reasons, the imagery gathered will not of high resolution, though both spacecraft will gather data that will eventually be correlated with similar data being gathered by Japan’s Akatsuki probe, in orbit around Venus since 2015.

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Sun unleashes strongest solar flare since last solar maximum

9:54 am

X1 solar flare as seen by Solar Dynamics Observatory

On July 3, 2021 the Sun emitted the first X-class solar flare of the rising present solar maximum, the first such flare since September 2017 during the previous maximum.

This flare is classified as an X1.5-class flare. X-class denotes the most intense flares, while the number provides more information about its strength. An X2 is twice as intense as an X1, an X3 is three times as intense, etc.

The image to the right was taken by the orbiting Solar Dynamics Observatory (SDO), designed to monitor the Sun continuously and catch such events.

More information here. The flare caused some disturbances to various radio instruments, though nothing that resulted in any serious consequences.

What the flare did demonstrate is that the Sun is definitely ramping up to solar maximum. In fact, the Sun has not been blank, with no sunspots on its facing hemisphere, since May 6th, the longest such stretch since the last solar maximum.

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Third set of new results from Parker released

9:32 am

The scientists using the Parker Solar Probe on June 2nd released their third set of new results as part of a special issue of the journal Astronomy & Astrophysics.

The latest articles include data analysis, theory, and modeling. Among the major topics covered are magnetic switchbacks first discovered by Parker Solar Probe, the role of waves in heating solar plasma, solar angular momentum, the near-Sun dust environment, and the diversity of small energetic-particle events.

The most interesting paper I think is the one describing data that lends strong weight to the theory, proposed in 1929 by astronomer Henry Norris Russell, that a dust-free zone exists close to the Sun and all stars. From the abstract:

The observed brightness decrease in the axis of symmetry is interpreted as the signature of the existence of a dust density depletion zone between about 19 [solar radii] and 3 [solar radii] which at the inner limit of WISPR’s field of view of 7.65 [solar radii] has a dust density that is ~5% lower than the density at 19 [solar radii], instead of the expected density which is three times if no depletion zone exists.

In plain English, the data shows that from about 1.3 million to 8.2 million miles from the Sun Parker found far less dust than predicted by other models. As the probe continues to lower its orbit and get closer to the Sun with each fly-by these numbers will be better refined, and are likely to in the end prove Russell’s hypothesis.

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Sunspot update: Activity in May continued to exceed predictions

11:07 am

Time for our monthly sunspot update. On June 1st NOAA updated its monthly graph showing the Sun’s sunspot activity through the end of May 2021. Below is that updated graph, annotated as always to show the previous solar cycle predictions.

As has happened now for almost every month since the Sun’s sunspot cycle began to increase following the long and deep minimum in 2019, the activity in June exceeded the numbers predicted by the computer models of NOAA’s panel of solar scientists. While the activity dipped slightly from April, it still was more active than predicted.

» Read more

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Parker makes course correction

9:25 am

On May 15th the Parker Solar Probe made the first of three small adjustments to its orbital path in order to refine its path during an October 16th fly-by of Venus, which in turn will make more precise its next three Venus fly-bys and thus bring it closer and closer to the Sun.

[The] Parker Solar Probe just completed its eighth close approach to the Sun, coming within a record 6.5 million miles (10.4 million kilometers) of the Sun’s surface on April 29. It’ll pass the Sun from about the same distance again on Aug. 9, before using Venus’ gravity on Oct. 16 to swing it even closer to the surface — about 5.6 million miles (9 million kilometers) — on Nov. 21. Assisted by the remaining three Venus flybys, Parker Solar Probe will eventually come within 4 million miles (6.4 million kilometers) of the solar surface.

The spacecraft remains healthy and continues to gather data with each fly-by of the both the Sun and Venus.

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Sunspot update: Sunspot activity continues to exceed predictions

1:29 am

The uncertainty of science: On May 1st NOAA updated its monthly graph to show the Sun’s sunspot activity through the end of April 2021. As I do every month, I have annotated it to show the previous solar cycle predictions and posted it below.

In my sunspot update last month I reviewed in detail the range of predictions by solar scientist for the upcoming solar maximum, noting that based on the higher than expected sunspot activity that has been occurring since the ramp up to solar maximum began in 2020, it appeared that all of their predictions might be wrong. The continuing high activity that occurred in April continued that trend.

» Read more

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Sunspot update: Higher than predicted activity continues

12:10 am

The uncertainty of science: Time for our monthly update of the Sun’s on-going sunspot cycle. Below is NOAA’s April 1, 2021 monthly graph, showing the Sun’s sunspot activity through the end of March 2021. I have annotated it as always to show the previous solar cycle predictions.

The higher than expected sunspot activity that has been occurring almost from the moment the ramp up to solar maximum began in 2020 continued in March. The numbers weren’t as high as they were in December and January, but they were still higher than the predicted sunspot number.

» Read more

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Sunspot update: February activity declines to predicted values

3:51 pm

Time to do another sunspot update. Below is NOAA’s March 1, 2021 monthly graph, showing the Sun’s monthly sunspot activity. It is annotated by me as always to show the previous solar cycle predictions.

February continued the decline of sunspot activity seen in January after a very unusually active November and December. Though the actual sunspot number was more than the prediction, the difference in February was trivial.
» Read more

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Sunspot update: January activity returns to expected levels

12:18 pm

Though I am a bit late this month, it is once again time provide my monthly update of the Sun’s on-going sunspot cycle. Below is NOAA’s February 1, 2021 monthly graph, showing the Sun’s monthly sunspot activity. I have, as I do each month, annotated it to show the previous solar cycle predictions.

After two months of relatively high activity, activity that was very high so early in the ramp up to solar maximum, the number of sunspots in January dropped down to closely match the predicted value. It was still higher, but not by much.

» Read more

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Parker completes 7th solar fly-by, sets new records

9:31 am

The Parker Solar Probe this week successfully completed its seventh close fly-by of the Sun, coming within 8.4 million miles and traveling at almost 300,000 miles per hour.

Nor is that all for 2021:

The spacecraft will make three more progressively close passes to the Sun in 2021 alone, as well as two gravity-assist flybys at Venus in February and October to adjust the trajectory of its orbit. After zipping past Venus on Feb. 20, Parker Solar Probe will again make close approaches to the Sun on April 29 and Aug. 9. Following another Venus gravity assist on Oct. 16, the spacecraft will make an even closer solar pass on Nov. 21, with perihelion just 5.3 million miles from the Sun’s surface.

Because the fly-bys of Venus are shrinking Parker’s solar orbit, the time between solar fly-bys is also shrinking.

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Sunspot update: December sunspot activity once again higher than predicted

1:11 pm

The uncertainty of science: It is time to once again take a look at the state of the Sun’s on-going sunspot cycle. Below is NOAA’s January 1, 2021 monthly graph, documenting the Sun’s monthly sunspot activity and annotated by me to show previous solar cycle predictions.

The ramp up to solar maximum continued in December. Though there was a drop from the very high activity seen in November, the number of sunspots in December still far exceeded the prediction as indicated by the red curve.

» Read more

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Sunspot update: November most active sunspot month since 2017

11:31 am

My monthly sunspot for December is late this month because I simply forgot to do it. (Thanks to reader Phill Oltmann for prodding my memory.)

Below is NOAA’s monthly graph for tracking the Sun’s monthly sunspot activity, annotated by me to show the past solar cycle predictions.

The increasing sunspot activity we saw in October continued spectacularly in November. In fact, the amount of activity was the most seen since the summer of 2017, when the last solar maximum gave us its last big outburst.

» Read more

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First sunspot image from Inouye Solar Telescope

8:42 am

Sunspot image taken by Inouye Solar Telescope
Click for full image.

The science team for the new Inouye Solar Telescope, now in the final phase of construction, has released the telescope’s first high resolution sunspot image.

The image is to the right, reduced to post here, and was taken almost a year ago, on January 28, 2020.

“The sunspot image achieves a spatial resolution about 2.5 times higher than ever previously achieved, showing magnetic structures as small as 20 kilometers on the surface of the sun,” said [Dr. Thomas Rimmele, the associate director at NSF’s National Solar Observatory (NSO)].

The image reveals striking details of the sunspot’s structure as seen at the Sun’s surface. The streaky appearance of hot and cool gas spidering out from the darker center is the result of sculpting by a convergence of intense magnetic fields and hot gasses boiling up from below.

…This sunspot image, measuring about 10,000 miles across, is just a tiny part of the Sun. However, the sunspot is large enough that Earth could comfortably fit inside.

The start of official telescope operations is set to begin in ’21, and had been delayed because of the Wuhan flu panic. Construction had begun in ’13.

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Parker completes record-setting sixth Sun fly-by

9:51 am

The Parker Solar Probe has successfully completed its sixth close fly-by of the Sun, flying as close as 8.4 million miles, the closest any spacecraft has ever gotten to the Sun, while also moving at a record speed of 289,927 miles per hour.

Flight controllers at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, received a “Status A” signal from the spacecraft through NASA’s Deep Space Network at 4:45 a.m. EDT; Status A is the best of four possible status signals, and indicates that the spacecraft is operating nominally.

The beacon comes after a six-day stretch when communications with the spacecraft were not possible as it wheeled around the Sun. This is the first sign of a successful solar encounter; this sixth solar encounter began Sept. 21 and continues through Oct. 2.

Future fly-bys will likely break this record as well.

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Scientists declare solar minimum over, with next sunspot maximum coming

10:47 am

Scientists from the government agencies of NOAA and NASA today announced that the solar minimum of the past sunspot cycle occurred in December 2019, and that the ramp up to the next solar maximum has begun, which they predict will be as active as the last weak maximum.

The announcement and prediction was put forth by “the Solar Cycle 25 Prediction Panel, an international group of experts co-sponsored by NASA and NOAA.” While this group is made up of legitimate scientists studying the Sun, its press releases tend to be lobbying efforts for government programs, which nicely describes today’s release as well. The release not only touts the importance of their work, it links this work to the Trump administration’s Artemis program to get back to the Moon.

Note also that this announcement only makes official what has been obvious for months, as I have noted in my monthly sunspot updates. See for example this quote from my September 7th update:

What is clear is that the activity does herald the next maximum. As in the past few months, the sunspots in August all had polarities that assigned them to the new maximum. While it is not impossible for there to be a handful of sunspots in the next few months that belong to the last maximum, it now appears that the last cycle is pretty much over. We are entering the ramp up to the next maximum, presently predicted by a portion of the solar science community aligned with NOAA to be a weak one.

The only change is that it appears they are upping their prediction for the next maximum slightly. Before the prediction panel had said that the next maximum would be weaker than the past maximum. Now they it appears they are saying it will be the same.

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Sunspot update: More evidence of an upcoming maximum

11:39 am

NOAA last week updated its monthly graph for tracking the Sun’s monthly sunspot activity. As I have done now for every month since 2011, I am posting that graph elow with additional annotations by me to show the past and new solar cycle predictions.

August 2020 sunspot activity

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 for the previous maximum, with half the scientists predicting a very strong maximum and half predicting a weak one. The blue curve is their revised May 2009 prediction. The red curve is the new prediction, first posted by NOAA in April 2020.

August continued the trends seen in the past two months whereby sunspot activity actually exceeded the prediction for this particular month.

Does this mean the prediction of a weak maximum in 2025 will be wrong? Hardly. Sunspot activity in any given month can easily be above or below the prediction, as is obvious if you compare the fluctuations of the last maximum with the prediction. We will not really know if these higher numbers the past few months mean anything until a lot more time has passed, with the gathering of a lot more data.

What is clear is that the activity does herald the next maximum. As in the past few months, the sunspots in August all had polarities that assigned them to the new maximum. While it is not impossible for there to be a handful of sunspots in the next few months that belong to the last maximum, it now appears that the last cycle is pretty much over. We are entering the ramp up to the next maximum, presently predicted by a portion of the solar science community aligned with NOAA to be a weak one.

Above all, the real scientific mystery remains: Scientists do not really yet understand the causes and processes that produce this sunspot cycle. They know without question that it is caused by cycles in the Sun’s magnetic dynamo, but their understanding of the details behind this process remain quite unknown.

Furthermore, the Sun’s importance to the climate on Earth is unquestioned. What we still do not know is its precise influence on long term climate changes. There is circumstantial evidence that it causes cooling and warming of the climate on scales of decades and centuries, but this remains unconfirmed. Once again, our understanding of the details behind the changes in the climate remain quite unknown.

And as always, the devil is in the details.

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Newly upgraded solar telescope sees first light

9:39 am

Early image from upgraded solar telescope.

Astronomers have finished a major instrument upgrade of the GREGOR solar telescope in the Canary Islands, making it possible for them to observe features on the Sun’s surface as small as thirty miles in diameter.

The image to the right is an example of the telescope’s new capability, showing the Sun’s granular surface features. From the introduction of the paper describing the upgrade:

GREGOR is Europe’s largest solar telescope. … Its 1.5 m diameter with an optical footprint of 1.44 m allows us to resolve structures on the Sun as small as 50 km at 400 nm.

…A past drawback of GREGOR was that its image quality did not reach the theoretical limit, partly because a risk was taken with untested technologies, such as silicon carbide mirrors, which could not be polished well enough, and partly because of design problems. These difficulties have recently been solved by replacing all silicon carbide mirrors with mirrors made of Zerodur, which can be polished to the required quality, and by redesigning the AO relay optics. GREGOR now operates at its diffraction limit. [emphasis mine]

In other words, the initial mirrors did not work as promised, requiring them to replace them to get the telescope to function as initially designed. By the image above, it looks like their upgrade has worked admirably.

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Sunspot update: Hints of the next maximum

11:07 am

It’s time for another monthly sunspot update! NOAA yesterday updated its monthly graph for tracking the Sun’s monthly sunspot activity, and as I do every month, I am posting it below with additional anotations by me to show the past and new solar cycle predictions.

July 2020 sunspot activity

The graph above has been modified to show the predictions of the solar science community for both the previous and upcoming solar maximums. The green curves show the community’s two original predictions from April 2007 for the previous maximum, with half the scientists predicting a very strong maximum and half predicting a weak one. The blue curve is their revised May 2009 prediction. The red curve is the new prediction, first posted by NOAA in April 2020.

July continued the trend from June, with a slight uptick in activity. The SILSO graph below for July illustrates this.
» Read more

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New model predicting solar flares is 56% accurate

1:01 pm

The uncertainty of science: Using observations from the space-based Solar Dynamics Observatory (SDO), solar scientists have developed a new model for predicting the biggest solar flares, and have found it to able to predict a big flare about 56% of the time.

Kusano and his team looked at the seven active regions from the last solar cycle that produced the strongest flares on the Earth-facing side of the Sun (they also focused on flares from part of the Sun that is closest to Earth, where magnetic field observations are best). SDO’s observations of the active regions helped them locate the right magnetic boundaries, and calculate instabilities in the hot spots. In the end, their model predicted seven out of nine total flares, with three false positives. The two that the model didn’t account for, Kusano explained, were exceptions to the rest: Unlike the others, the active region they exploded from were much larger, and didn’t produce a coronal mass ejection along with the flare. [emphasis mine]

What they did was apply their model to active regions on the Sun during the last solar maximum to see if it would accurately predict the events we know did happen. The model predicted that big flares would spout from ten of twelve active regions on the Sun during the last solar cycle. In reality, only seven of those twelve active regions produced flares.

The press release minimizes the three false positives, making believe they don’t count in the total. That’s hogwash. The model got it wrong, and so these false positives must be counted just like the two false negatives.

A prediction rate of 56% is barely above random, so this model needs a lot of work. Nonetheless, it is a major step forward, because it is not based on simple statistics — counting the number of big sunspots and the number of big flares and then calculating the percentage that flare — which is how most solar science models are structured, and thus are really meaningless. Instead, this model is based an actual analysis of the behavior of the Sun’s magnetic field in big active regions when solar flares erupt. They are trying to pinpoint the precise conditions that cause the big flares, and appear to be narrowing the conditions successfully.

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Solar Orbiter’s first images, the closest ever of Sun

10:07 am

Campfires on Sun
Click for full image.

The Solar Orbiter science team today released the first images taken during the spacecraft’s first close fly-by of the Sun.

The image to the right, reduced to post here, highlights what they are touting as their first discovery, what they have dubbed “campfires” on the solar surface, small flares previously not known to exist.

The campfires shown in the first image set were captured by the Extreme Ultraviolet Imager (EUI) from Solar Orbiter’s first perihelion, the point in its elliptical orbit closest to the Sun. At that time, the spacecraft was only 77 million km away from the Sun, about half the distance between Earth and the star. “The campfires are little relatives of the solar flares that we can observe from Earth, million or billion times smaller,” says David Berghmans of the Royal Observatory of Belgium (ROB), Principal Investigator of the EUI instrument, which takes high-resolution images of the lower layers of the Sun’s atmosphere, known as the solar corona. “The Sun might look quiet at the first glance, but when we look in detail, we can see those miniature flares everywhere we look.”

The scientists do not know yet whether the campfires are just tiny versions of big flares, or whether they are driven by different mechanisms. There are, however, already theories that these miniature flares could be contributing to one of the most mysterious phenomena on the Sun, the coronal heating.

Much more to come in future orbits, as the spacecraft works its way even closer to the Sun.

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Solar Orbiter operational, first images to be released

10:05 am

Engineers have now confirmed that Solar Orbiter, having completed its first close fly-by of the Sun, is working perfectly and is producing images and data better than expected.

They will release to the public the first images on July 16.

“The first images are exceeding our expectations,” says Daniel Müller, Solar Orbiter Project Scientist at ESA. “We can already see hints of very interesting phenomena that we have not been able to observe in detail before. The 10 instruments on board Solar Orbiter work beautifully, and together provide a holistic view of the Sun and the solar wind. This makes us confident that Solar Orbiter will help us answer profound open questions about the Sun.”

No other images of the Sun have been taken from such a close distance. During its first perihelion, the point in the spacecraft’s elliptical orbit closest to the Sun, Solar Orbiter got as close as 77 million kilometres from the star’s surface, about half the distance between the Sun and Earth. The spacecraft will eventually make much closer approaches to the Sun. The spacecraft is now in its cruise phase, gradually adjusting its orbit around the Sun. Once in its science phase, which will commence in late 2021, the spacecraft will get as close as 42 million kilometres from the Sun’s surface, closer than the planet Mercury. The spacecraft’s operators will gradually tilt Solar Orbiter’s orbit to enable the probe to get the first proper view of the Sun’s poles.

A previous spacecraft, Ulysses, flew over the Sun’s poles, but it did it from far away, and was designed not to take images but to study the Sun’s solar wind. Solar Orbiter is getting in close.

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Sunspot update: More evidence of an upcoming weak maximum

11:31 am

On July 4th NOAA updated its monthly graph tracking the monthly activity of sunspots on the Sun’s visible hemisphere. Below is that updated graph, annotated by me to show the past and new solar cycle predictions.

June 2020 sunspot activity

The graph above has been modified to show the predictions of the solar science community for both the previous and upcoming solar maximums. The green curves show the community’s two original predictions from April 2007 for the previous maximum, with half the scientists predicting a very strong maximum and half predicting a weak one. The blue curve is their revised May 2009 prediction. The red curve is the new prediction, first posted by NOAA in April 2020.

June saw an uptick of activity since my last update, though that activity remains quite low. We saw two sunspots during the month, both with polarities that link them to the next maximum and thus providing evidence that we will have a maximum in about five or six years. The first of those sunspots was also one of the strongest new cycle sunspots yet seen, and lasted for almost two weeks before it rotated off the visible face of the sun.

The ratio of next cycle sunspots vs sunspots from the past maximum has also been shifting. More and more, the new sunspots belong to the next cycle and less to the last. The ramp up to the next maximum is definitely beginning, though to call it a “ramp up” at this point is a big exaggeration. Sunspot activity remains low, though the last few months have seen some activity, unlike the seven months of nothing seen during the second half of last year.

The upcoming prediction for the next maximum calls for it to be very weak. Interestingly, the activity in June surpassed that prediction. This does not mean that the prediction will be wrong, only that June was more active when compared to the smooth prediction curve. As the cycle unfolds the monthly numbers will fluctuate up and down, as they did last cycle. The question will be whether their overall numbers will match closely with the prediction. In the past cycle actual sunspot activity was consistently below all predictions. It is too soon to say how well the new prediction is doing.

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NOAA awards contract to private company for solar observatory

9:22 am

Capitalism in space: NOAA today awarded a contract to the private company Xplore to study development of a commercial solar observatory at the Earth-Sun L1 point.

The press release at the link is somewhat vague about the contract. It appears to be a study to see if Xplore’s proposed Xcraft spacecraft can be used as platform for such a solar observatory, not an actual contract to build the observatory.

Regardless, this award is a strong indicator that the Trump administration is applying pressure at NOAA to get it out of the business of building weather satellites and instead be a customer buying such satellites from the private sector. The weather agency has been, like NASA earlier this decade, resistant to this concept, with its bureaucracy wanting to retain control over everything. Maybe the success of SpaceX at NASA is now helping to fuel the change at NOAA.

Let us hope so. NOAA’s present fleet of solar observatories in space is years past their due date, with no sign of a replacement fleet. The agency just can’t seem to get its act together to build these satellites. For example, NOAA has been trying and failing to build a new solar observatory to monitor sunspot activity now for more than a decade.

Maybe, like NASA, giving the job to private enterprise might get things going.

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Parker successfully completes fifth solar fly-by

9:42 am

The Parker Solar Probe has signaled scientists that it has successfully completed its fifth solar fly-by without damage.

On June 9, 2020, NASA’s Parker Solar Probe signaled the success of its fifth close pass by the Sun, called perihelion, with a radio beacon tone. The spacecraft completed the fifth perihelion of its mission two days prior, flying within 11.6 million miles from the Sun’s surface, reaching a top speed of about 244,225 miles per hour, which matches the spacecraft’s own records for closest human-made object to the Sun and fastest human-made object, set during its fourth orbit on January 29.

Mission controllers at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, received a “status A” beacon from the spacecraft at 4:40 p.m. EDT. Status A is the best of four possible status signals, and indicates that the spacecraft is operating nominally and the instrument suites are collecting science data. This beacon tone comes after a five-day period where communications with the spacecraft were not possible.

The data from this fly-by will arrive during the summer. Meanwhile, the spacecraft will next do a fly-by of Venus to slow it down further so that it can get even closer to the Sun on its next orbit.

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Sunspot update: The deep minimum deepens

12:07 pm

NOAA last week did its monthly update of its graph for tracking the monthly activity of sunspots on the Sun’s visible hemisphere. Below is that updated graph, annotated by me to show the past and new solar cycle predictions.

May 2020 sunspot activity

The graph above has been modified to show the predictions of the solar science community for both the previous and upcoming solar maximums. The green curves show the community’s two original predictions from April 2007 for the previous maximum, with half the scientists predicting a very strong maximum and half predicting a weak one. The blue curve is their revised May 2009 prediction. The red curve is the new prediction, first posted by NOAA in April 2020.

Since last month NOAA has done some further revisions to this graph, and improved it significantly since their first redesign, released in April. You can see the difference just by comparing it to my previous update last month. For scales covering longer periods, they have eliminated the diamonds, making the curve much more readable. They have also increased the size of the graph, which also serves to make it more readable as well. Kudos to the people at NOAA for these changes.

As you can see, sunspot activity in May plunged from the slight uptick in April. This is even more clearly shown by the SILSO graph below.
» Read more

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Parker extends length of science operations during upcoming fifth solar fly-by

9:22 am

The science team for the Parker Solar Probe have decided to extend the period the spacecraft’s instruments are operating during its fifth close fly-by of the Sun, based on the data they have obtained from the first four fly-bys.

On May 9, 2020, NASA’s Parker Solar Probe began its longest observation campaign to date. The spacecraft, which has already completed four progressively closer orbits around the Sun, activated its instruments at a distance of 62.5 million miles from the Sun’s surface, some 39 million miles farther from the Sun than a typical solar encounter. The four instrument suites will continue to collect data through June 28, markedly longer than the mission’s standard 11-day encounters.

The nearly two-month campaign is spurred by Parker Solar Probe’s earlier observations, which revealed significant rotation of the solar wind and solar wind phenomena occurring much farther from the Sun than previously thought. The earlier activation of the science instruments allows the team to cover a larger range in order to trace the evolution of the solar wind as it moves away from the Sun.

Perihelion will occur on June 7 at a distance of 11.6 million miles from the Sun. That will match the previous record set during Parker’s previous orbit for the closest solar fly-by ever. They will then follow this with another fly-by of Venus, which will tighten the orbit even more.

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Sunspot update: The deep minimum continues

1:00 pm

Last week NOAA updated its graph for tracking the monthly activity of sunspots on the Sun’s visible hemisphere. Below is that updated graph, annotated by me to show the past and new solar cycle predictions.

April 2020 sunspot activity

The graph above has been modified to show the predictions of the solar science community for both the previous and upcoming solar maximums. The green curves show the community’s two original predictions from April 2007 for the previous maximum, with half the scientists predicting a very strong maximum and half predicting a weak one. The blue curve is their revised May 2009 prediction. The red curve is the new prediction, first posted by NOAA in April 2020.

Because of the design of this graph, revamped by NOAA in April, it is difficult at this scale — which for context shows both the past cycle and the predicted future cycle — to see the addition of the April sunspot total, when compared to last month’s graph. Trust me, it is there. In April sunspot activity went up, but trivially so, with only four sunspots during the month, three of which had a magnetic polarity assigning them to the next solar maximum.

The solar minimum remains very deep, deeper than the very deep previous minimum, and possibly the least active in two hundred years. The presence however of more sunspots for the new cycle strengthens the expectation that we will not be entering a grand minimum, with no sunspots for decades. It just appears that, as predicted, the next solar maximum will be a very weak one.

How this weak activity will effect the climate remains an unknown. In the past, such as the weak maximum that just ended as well as during past weak maximums at the beginning of the 1800s and the 1900s, the Earth’s climate cooled. It also cooled during the Little Ice Age in the 1600s, during the last grand minimum.

Whether the same will happen in the next decade remains unknown. Global warming activists will claim impossible, we are all going to die from overheating. The data for the past decade proves them wrong, though in the coming years they might be vindicated.

All we can do is wait, pay attention to the data, and make our conclusions from that.

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The Sun fluctuates far less than other similar stars

12:24 pm

A new survey of 369 sun-like stars has confirmed what earlier studies have shown, that the Sun is remarkable inactive compared with similar stars.

A comprehensive catalogue containing the rotation periods of thousands of stars has been available only for the last few years. It is based on measurement data from NASA’s Kepler Space Telescope, which recorded the brightness fluctuations of approximately 150000 main sequence stars (i.e. those that are in the middle of their lifetimes) from 2009 to 2013. The researchers scoured this huge sample and selected those stars that rotate once around their own axis within 20 to 30 days. The Sun needs about 24.5 days for this. The researchers were able to further narrow down this sample by using data from the European Gaia Space Telescope. In the end, 369 stars remained, which also resemble the Sun in other fundamental properties.

The exact analysis of the brightness variations of these stars from 2009 to 2013 reveals a clear picture. While between active and inactive phases solar irradiance fluctuated on average by just 0.07 percent, the other stars showed much larger variation. Their fluctuations were typically about five times as strong. “We were very surprised that most of the Sun-like stars are so much more active than the Sun,” says Dr. Alexander Shapiro of MPS.

It is possible that this inactivity might be because the Sun just happens to be going through a quiet phase, but that is becoming increasingly less likely as the surveys find more and more sun-like stars, and none as inactive as the Sun.

If the Sun is this unusual, we must ask if this inactivity is a fundamental requirement for life to form. Active stars provide a more inhospitable environment. If inactive stars like the Sun are very rare, however, that suggests that life itself in the universe could be very rare as well.

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NOAA’s prediction for the next solar maximum

10:02 am

Last week NOAA introduced a newly revamped graph for tracking the monthly activity of sunspots on the Sun’s visible hemisphere. (You can see an example of the old graph, used by them for more than fifteen years, here.)

In order to properly understand the context of future sunspot activity, it is important to understand how the new graph aligns with the old. My first attempt to do so in my April 3, 2020 sunspot update, unfortunately was a failure. While most of my conclusions in that update remain correct, my attempt to place NOAA’s prediction for the next solar cycle on my graph was in error.

I had not realized that NOAA had changed its sunspot number scale on the graph’s vertical axis. In their old graph they had used the monthly sunspot number count from the Royal Observatory of Belgium. The new graph instead used the sunspot number from NOAA’s own Space Weather Prediction Center (SWPC). Both numbers are creditable, but the solar scientist community has switched entirely to the latter in the past few years because they consider its criteria for determining the count across all past cycles to be more accurate.

The Belgium numbers have traditionally been about one third lower than SWPC’s. Not realizing that NOAA’s new prediction was based on the SWPC numbers, I therefore placed it on the graph using the Belgium numbers and thus made the peak of the solar maximum 33% too high.

Below is NOAA’s new graph, annotated properly with both the past and new solar cycle predictions added now correctly.
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Sunspot update: The flatline resumes

12:17 pm

NOAA this week released its February update of its monthly graph showing the long term sunspot activity of the Sun. Below is my monthly version, annotated as I have done every month since 2011.

After a tiny uptick in sunspot activity in January, the Sun resumed the unprecedented flatlining of sunspot activity that began last June. Since then, the Sun has produced practically no sunspots, a drought that as far as I can tell has never happened since the 11-year sunspot cycle resumed in the 1700s (after the grand minimum in the 1600s) and astronomers began counting sunspots.

February 2020 sunspot activity
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.

February saw only one sunspot, and it belonged to the old solar cycle. It also occurred at the beginning of the month, and was followed by 33-day streak of blankness, into the middle of March, when a sunspot from the new cycle appeared and quickly faded.

The continuing overall lack of sunspots, from either the old or new cycle, does not mean that we are entering a new grand minimum, with no sunspots for decades (though some scientists believe we are). It does suggest however that the next solar maximum will be weak, and very likely weaker than the very weak maximum that just ended.

Why the Sun does this remains a mystery. Scientists really have no fundamental understanding of the magnetic processes that produce the Sun’s sunspot cycles. And since that cycle appears to have some effect on the Earth’s climate, it also means scientists do not yet have a fundamental understanding of the climate either.

Not that this lack of knowledge matters anymore. We are in an age of panic and certainty, based on emotion and feelings. All that matters is that many people feel they understand the climate and how the Sun works, just as everyone is sure that COVID-19 will destroy the world if we don’t shut down all human activity.

They are certain, and any additional data that illustrates that certainty is unwarranted is irrelevant and must be ignored.

Certainty however is a very dangerous thing. The universe is always more complicated than we know, and to assume we now understand all without doubt leaves us very vulnerable to some bad surprises, as well as the chance we will take actions that are foolish, inappropriate, and even downright evil.

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