A Solar Science Timeline – sunspots, cycles, and solar wind

Humankind has studied the Sun for millennia. Ancient Babylonians recorded eclipses on stone tablets. Renaissance scientists peered through telescopes, tracking sunspots. Eventually we took to space, and the first satellites captured solar particles streaming past Earth.

Each generation ran against the limits of their tools. So they built new ones, and a new bounty of questions emerged. Today, cutting-edge solar research can still trace its lineage to the efforts of early, Earth-bound Sun-watchers who were just as eager to understand our closest star. This is an abridged story of that scientific history: A genealogy of the advances that led to solar science as we know it today.

View an interactive version of this timeline.


1375 BCE – 1543 CE — EARLY HISTORY OF SOLAR SCIENCE

eclipse tablet

Long before they had telescopes, humans kept an eye on the Sun.1375 BCE: Babylonians used stone tablets to record solar eclipses.800 BCE: Astronomers in the ancient China recorded the first observations of sunspots in I Ching, the Book of Changes.150 CE: Claudius Ptolemy wrote The Almagest, describing a universe with Earth at the center and the Sun, planets and stars circling around it.

1543 CE: Nicolaus Copernicus publishes De Revolutionibus Orbium Coelestium, a new planetary model that placed the Sun, not Earth, at the center.

Caption: Babylonian Solar Eclipse Tablet listing eclipses between 518 and 465 BCE. Credit: By Jona Lendering, CC0 1.0 Universal


1608 — INVENTION OF THE TELESCOPE

Engraving of Dutch Perspective Glass

German-Dutch lensmaker Hans Lippershey applies for a patent for his Dutch Perspective Glass. The device combined concave and convex lenses to magnify objects by three times.

Italian astronomer Galileo Galilei learns of the invention in 1609, refining the design to achieve 20-fold magnification. Galileo becomes the first to turn this device skyward to make astronomical observations. Around 1610, he would also begin to keep track of mysterious dark spots on the Sun. 

Caption: Early depiction of the Dutch Perspective Glass circa 1624. Credit: Adriaen van de Venne/Public domain


APRIL 19, 1610 — THE SUN’S “HEAVENLY BREEZE”

Comet ISON

In a letter to Galileo, Johannes Kepler hypothesized that the tails of comets are blown away by a “heavenly breeze” from the Sun.

Kepler’s suggestion anticipates the discovery of the solar wind more than 400 years later.

Caption: CoComet ISON streaks across the sky 80 million miles from Earth. Credit: NASA’s Marshall Space Flight Center/Aaron Kingery


1611-1613 — A SPOTTY, SPINNING SUN

Spinning Sun with sunspots

In 1611, Johann Goldsmid of Holland observes what might be spots on the Sun. The spots drifted across the Sun’s disk, suggesting that the Sun rotates. Galileo demonstrates that these dark spots were physical features on the Sun, not undiscovered planets in space, in his in his Letters on Sunspots, published in 1613.

The detection of imperfections and changes on the Sun challenged the view (prevailing since Aristotle’s time) that the Sun was a perfect and unchanging orb.

Caption: Sunspots observed by the Helioseismic and Magnetic Imager aboard NASA’s Solar Dynamics Observatory. Credit: NASA’s Solar Dynamics Observatory/Goddard Space Flight Center Scientific Visualization Studio
 


1645-1715 — SUNSPOTS SUBSIDE

Plot of Maunder Minimum

For seventy years, astronomers record an unusally low number of sunspots. This period was later named the “Maunder Minimum” after Annie (1868–1947) and Edward Maunder (1851–1928), a husband and wife team who studied how sunspot positions changed over time.

Caption: Sunspots observed by the Helioseismic and Magnetic Imager aboard NASA’s Solar Dynamics Observatory. Credit: NASA’s Solar Dynamics Observatory/Goddard Space Flight Center Scientific Visualization Studio
 


1802-1895 — A NEW SCIENCE OF SPECTROSCOPY

Plot of spectral lines

1802: English scientist William Hyde Wollaston notices that sunlight passing through a prism contains mysterious dark lines.1817: Bavarian physicist Joseph von Fraunhofer independently rediscovers these dark “spectral lines.” He begins labeling and systematically investigating them.

1859: German physicist Gustav Kirchhoff discovers that each atomic element leaves its own unique set of spectral lines. Spectroscopy becomes a tool for determining the composition of distant light sources.

Caption: During the Maunder Minimum, sunspots were rarely observed. Credit: NASA’s Marshall Space Flight Center


JULY 8, 1842 — THE SUN HAS AN ATMOSPHERE

Eclipse image

Observing an eclipse from Italy, English astronomer Francis Baily suggests that the mysterious haze encircling the Sun — known as the corona, Latin for crown — is the Sun’s atmosphere.

Caption: Spectral lines appear at characteristic locations along the electromagnetic spectrum, indicating the presence of specific atomic elements. Credit: NASA/JPL 

 


1843 — DISCOVERY OF THE SUNSPOT CYCLE

Close-up of sunspots

German astronomer Samuel Heinrich Schwabe studies the Sun for 17 years, looking for tiny shadows cast by undiscovered planets inside the orbit of Mercury. He also carefully monitors sunspots, since they could easily be mistaken for such shadows.

Schwabe never finds the shadows he was looking for. Instead, in 1843 he discovers the sunspot cycle: The average number of sunspots increases and then decreases with a period that Schwabe originally estimated to be 10 years (later estimates would put it at 11 years).

Caption: Traveling sunspots are seen by NASA’s Solar Dynamics Observatory (SDO) satellite from Oct. 25 to 27, 2010. Credit: NASA’s Goddard Space Flight Center/Scientific Visualization Studio


SEPTEMBER 1, 1859 — THE CARRINGTON EVENT

Simulation of Carrington Event

As English astronomer Richard Carrington watches the Sun through his telescope, he notices a sudden brightening on the Sun’s surface like he’d never seen before.Seventeen hours later, the northern lights are visible as far south as Cuba. Telegraph systems across the western world fail and catch fire, in some cases giving their operators electric shocks.The Carrington Event, as it would later become known, was a white light flare, a rare phenomenon not observed again for over 50 years. It was also the first documented case of a geomagnetic storm associated with a coronal mass ejection, or CME, in which charged particles from the Sun are ejected in an explosive burst.

Caption: A modern simulation of Earth’s magnetic field during the Carrington event. Credit: NASA’s Goddard Space Flight Center/Scientific Visualization Studio/Tom Bridgman


1868-1895 — DISCOVERY OF HELIUM

Animation of Helium atom

1868: French astronomer Pierre Jules César Janssen detects unknown spectral line during an eclipse. Later scientists repeating this observation dub it a new chemical element named helium (from the Greek “helios,” meaning Sun).

1895: Scottish chemist William Ramsey discovers helium on Earth. We now know it is one of the most abundant elements in the universe, second only to hydrogen.

Caption: An animation of a standard helium atom, showing its protons (green), its neutrons (white), and its electrons (blue). Credit: NASA/Dana Berry


1869 — HINTS OF A CORONAL MYSTERY

Spectral lines attributed to Coronium

Watching the 1869 total solar eclipse, American astronomers Charles Augustus Young and William Harkness observe an unusual green emission line of wavelength 530.3 nanometers, not associated with any elements known on Earth.On the heels of the discovery of helium, scientists posit that the line came from a new element: coronium.

It would be more than seventy years before the anomalous spectral line was correctly identified, revealing that it was from a known element at much hotter temperatures than ever before observed. The discovery would open up new questions about the corona’s extreme temperature.

Caption: The green spectral line seen during a total solar eclipse was once thought to be the element coronium. Credit: NASA’s Goddard Space Flight Center/Scientific Visualization Studio/Joy Ng


1908 — THE SUN IS MAGNETIC

Animation of Sun's flipping magnetic polarity

American astronomer George Ellery Hale notices that spectral lines split in regions near a sunspot. The phenomenon, known as the Zeeman effect, was known to occur in the presence of intense magnetic fields. His results suggest that sunspots have magnetic fields over a thousand times stronger than Earth’s.Over the following decade, Hale and colleagues discover that the changing number of sunspots reflects a larger magnetic process on the Sun known as the solar cycle. Every 22 years — twice the length of the sunspot cycle — the magnetic polarity of the Sun reverses. North becomes south, and vice versa.

Caption: An animation of the Sun’s magnetic poles flipping during its 22-year magnetic cycle. Credit: NASA’s Goddard Space Flight Center


MAY 29, 1919 — ECLIPSE CONFIRMS RELATIVITY

1919 eclipse image

English astronomer Sir Arthur Eddington observes starlight bending around the Sun’s limb during a solar eclipse. The observations confirm a key prediction of the theory of General Relativity. The theory’s creator, a physicist named Albert Einstein, becomes world famous overnight.

Caption: Inverted image of the eclipse on May 29, 1919. Credit: F. W. Dyson, A. S. Eddington, and C. Davidson/Public domain








 


1931 — ARTIFICIAL ECLIPSES ACCELERATE SUN SCIENCE

Bernard Lyot at his coronagraph

French astronomer Bernard Lyot invents the coronagraph, a telescope that selectively mimics a solar eclipse by blocking out light from the Sun’s bright surface. For the first time, scientists could see — and therefore study — the corona without having to wait for a natural eclipse.

Caption: Bernard Lyot sitting at his Coronagraph at the Pic du Midi observatory in France ca 1939. Credit: Courtesy of the American Museum of Natural History









 


JULY 1942 — THE CORONAL HEATING PROBLEM IS BORN

Animation of hot solar atmosphere and cooler surface

Swedish astronomer Bengt Edlen shows that the anomalous spectral lines in the corona previously credited to an unknown element found only on the Sun — coronium — in fact come from iron that had lost 13 electrons. Such a loss requires extremely high temperatures: approximately 3 million degrees Fahrenheit, much hotter than the 10,000 degree solar surface.Edlen’s finding gave rise to what we now call the coronal heating problem: How does the solar atmosphere become so much hotter than its surface?

Caption: The Sun’s surface is 10,000 degrees Fahrenheit while the corona — the Sun’s outer atmosphere — is several hundred times hotter. Credit: NASA’s Goddard Space Flight Center/Scientific Visualiation Studio/Joy Ng


1946 — SOLAR ENERGETIC PARTICLES DETECTED AT EARTH

Animated image of Solar Flare

Scott Forbush, a physicist working out of the Carnegie Institution in Washington, D.C., is monitoring the rate of incoming energetic particles when he detects a spike not long after a solar flare occurs on the Sun. The first time energetic particles (protons, formed from ionizing hydrogen) from the Sun were detected at Earth, Forbush’s findings solidify the concept of space weather — conditions in near-Earth space were affected by varying activity on the Sun.

Caption: On Oct. 24, 2014, NASA’s Solar Dynamics Observatory observed an X-class solar flare — the most intense rating for solar flares — erupt from a Jupiter-sized sunspot group. Credit: NASA’s Goddard Space Flight Center/SDO/Joy Ng

 


1955 — A BUBBLE AROUND THE SUN

Zooming out from Sun to heliosphere

Leverett Davis Jr., a theoretical physicist at the California Institute of Technology, comes up with the concept of the heliosphere: a giant magnetic bubble around the Sun. As solar activity increases, the bubble grows larger, fighting back the cosmic rays — energetic particles from deep space — that could make it through to Earth.This bubble was hypothesized — correctly, as it turns out — to be formed by a constant stream of solar particles flowing from the Sun. But the mechanisms for this outflow were not understood.

Caption: An animation of the heliosphere. Credit: NASA’s Goddard Space Flight Center/Conceptual Image Lab/Walt Feimer


OCTOBER 1, 1958 — NASA OPENS, PLANS SOLAR PROBE

Eisenhower and NASA administrators at NASA opening

The National Aeronautics and Space Administration, or NASA, opens for business.The National Research Council’s Space Studies Board receives an interim report with recommendations for future missions. Among them was that of a solar probe to travel inside the orbit of Mercury and measure the particles and fields environment near the Sun.

Caption: President Dwight Eisenhower (center) presents commissions to T. Keith Glennan (left) and Hugh L. Dryden (right), NASA’s first administrator and deputy administrator respectively. In July 1958, Eisenhower had signed the National Aeronautics and Space Act, creating the agency, which opened for business on Oct. 1, 1958. Credit: NASA


NOVEMBER 1958 — EUGENE PARKER PREDICTS THE SOLAR WIND

Sun and solar wind

Eugene Parker, a young astrophysicist at the University of Chicago, was puzzled by the coronal heating problem. Why didn’t the multi-million degree solar atmosphere fly right off the Sun? The answer, he found, is that it wouldn’t.According to Parker’s paper, published in November 1958, the hot solar atmosphere expands continuously outward from the Sun in all directions, forming a solar wind. This solar wind blows up the heliospheric “bubble” hypothesized by Leverett Davis, Jr. in 1955. But it would also drag the Sun’s magnetic field along with it. Given the Sun’s continuous rotation as the solar wind travels straight outwards, the magnetic field lines would bend into a twisting, ballerina-skirt-like shape that came to be known as the Parker spiral.

However, Parker’s ideas were purely theoretical. No one had ever directly measured the solar wind — yet.

Caption: Starting with a coronal mass ejection captured by NASA’s Solar Dynamics Observatory (171 angstrom telescope), this animation zooms out to show an animated solar wind. Credit: NASA’s Goddard Space Flight Center/Scientific Visualization Studio


1959 — SOLAR WIND IS MEASURED

Image of Luna 1

The Soviet satellite Luna 1 becomes the first spacecraft to leave geocentric orbit, venturing outside of Earth’s magnetic field into interplanetary space. There it observes a slew of hot particles streaming by at incredible speeds. Three years later, NASA’s Mariner 2 mission confirmed these observations while on its way to Venus. There was no longer any doubt: The solar wind exists.

Caption: Luna 1 was the first human-made object to escape the grip of Earth’s gravity. Credit: NASA/JPL



 


1967 — A SPINNING SOLAR ATMOSPHERE?

Rotating Sun from SDO imagery

Scientists knew that stars spin. But what about their atmospheres?Edmund J. Weber and Leverett Davis, Jr. of Caltech publish a paper suggesting that stellar atmospheres spin along with their surfaces. As the tips of their atmospheres blew off into the stellar wind, the star would lose angular momentum, rapidly slowing down its spin. It could explain why stars all over the universe were slowing down faster than expected.A promising idea — but the spin of our own Sun’s atmosphere had never been documented. So began a decades-long hunt to see the Sun’s corona spin.

Caption: Images of the Sun taken by NASA’s Solar Dynamics Observatory in a wavelength of ultraviolet light (171 angstrom). Credit: NASA/SDO


DECEMBER 14, 1971 — FIRST CORONAL MASS EJECTION SEEN FROM SPACE

Coronagraph images of CME

The Orbiting Solar Observatory-7 spacecraft carries a coronagraph into space. Looking over the data, Richard Tousey of the Naval Research Laboratory in Washington, D.C. observes an unusual bright spot in part of the image, and worries the camera has failed.As the bright spot moves away from the Sun in subsequent images, he realizes he’s observed a coronal mass ejection, or CME. These magnetic solar eruptions had been predicted in the 60’s, but had never before been observed in space.Unlike the continuous solar wind, CMEs are bursts of high speed particles that are potentially dangerous.

Caption: The first images of a coronal mass ejection from space, seen here as lighter material leaving from the bottom left side of each image, were captured by the OSO-7 spacecraft. Credit: NASA


APRIL 17, 1976 — HELIOS MISSION BECOMES CLOSEST SPACECRAFT TO THE SUN

Helios spacecraft

The twin Helios 1 and 2 spacecrafts launch on Dec. 10, 1974, and Jan. 15, 1976, respectively. Both orbit the Sun, studying it intensively until 1985. On April 17, 1976, Helios 2 becomes the first spacecraft to enter inside the orbit of Mercury, traveling as close at 26.55 million miles to the Sun, bringing it less than one third the distance from the Sun to Earth.The Helios mission greatly improved our understanding of how the solar wind behaved before it reached Earth, revealing that the solar wind is much more variable the closer it is to the Sun.

Caption: The Helios spacecraft before launch. Credit: NASA/JPL


NOVEMBER 1, 1994 — WIND MEASURES THE WIND

Wind spacecraft and Earth's magnetosphere

NASA’s Wind spacecraft launches. Wind first travels to the L1 lagrange point, outside Earth’s protective magnetic field between the Sun and Earth, then moves to L2, on the other side of Earth. In both locations, the spacecraft makes the highest time resolution measurements of the solar wind to date, uncovering a range of new wave-particle interactions in the solar wind in the process.

Caption: Illustration of the Wind spacecraft outside Earth’s magnetosphere. Credit: NASA


1995-2010 — MORE, AND BETTER, VIEWS OF THE SUN

STEREO and SDO capture the same active region

Dec 2., 1995: ESA/NASA Solar and Heliospheric Observatory, or SOHO launches. Using SOHO data, Neil R. Sheeley Jr. of the Naval Research Laboratory identifies giant blobs of slow solar wind escaping from the top of helmet streamers — large, bright, loop-like structures that stream into space from the Sun’s edge.Oct. 25, 2006: NASA’s two Solar and Terrestrial Relations Observatory or STEREO satellites launch to orbit the Sun, one ahead of Earth and the other behind. Combining their vantage points, they reveal the first 360-degree view of the Sun.Feb. 11, 2010: NASA’s Solar Dynamics Observatory, or SDO, launches into geostationary orbit. SDO continuously observes the Sun in 10 different wavelengths of extreme ultraviolet light, capturing a new image every 10 seconds.

Caption: Views of Active Region 1087 from the SDO/AIA (Atmospheric Imaging Assembly) imager and STEREO/EUVI (Extreme UltraViolet Imager) imager. Credit: NASA’s Goddard Space Flight Center/Scientific Visualization Studio/Tom Bridgman


AUGUST 12, 2018 — PARKER SOLAR PROBE LAUNCHES

Eugene Parker watches launch of Parker Solar Probe

NASA’s Parker Solar Probe — the first NASA mission to be named for a living person — launches from the Cape Canaveral in Florida.

Caption: Dr. Eugene Parker watches the launch of the spacecraft that bears his name — NASA’s Parker Solar Probe — early in the morning of Aug. 12, 2018. Credit: NASA’s Goddard Space Flight Center
 


1:04 AM OCTOBER 29, 2018 — PARKER SOLAR PROBE BECOMES CLOSEST SPACECRAFT TO THE SUN

Animation of Parker Solar Probe in front of the Sun

Surpassing the record set by the German-American Helios 2 spacecraft in 1976, Parker Solar Probe travels within 26.55 million miles of the Sun to become the closest spacecraft to the Sun. About ten hours later it also becomes the fastest spacecraft, surpassing the 153,454 miles per hour record also set by Helios 2.Over the course of its nominal 7 year mission, Parker Solar Probe will travel as close as 3.8 million miles from the solar surface and reach speeds of up to 430,000 miles per hour.

Caption: An animation of Parker Solar Probe passing near the Sun. Credit: NASA’s Goddard Space Flight Center/Scientific Visualization Studio


2019 — FIRST PUBLISHED RESULTS FROM PARKER SOLAR PROBE

Switchbacks in the solar wind

Early results from Parker reveal the surprises that come from studying the Sun up close. Findings from 2019 include:• Unanticipated “switchbacks” in the solar wind, where the Sun’s magnetic field abruptly doubles-back on itself,• Evidence for a “dust-free zone” — first hypothesized in 1929, but never successfully detected — beginning an estimated 3.5 million miles from the Sun,• The first measurement of rotation in the solar wind — remnants of the corona’s spin much farther from the Sun, before it begins to flow radially, or straight out from the Sun, as it does near Earth.• Detections of never-before-seen particle events so small that all trace of them is wiped out before they reach Earth.

Caption: Animation of Sun’s magnetic field lines, including “switchbacks” detected by Parker Solar Probe. Credit: NASA’s Goddard Space Flight Center/Conceptual Image Lab


FEBRUARY 2020 — SOLAR ORBITER TO LAUNCH FROM CAPE CANAVERAL

Solar Orbiter faces the Sun

The ESA/NASA Solar Orbiter mission launches on a path out of the ecliptic plane — the belt of space, encircling the Sun’s equator, in which all planets orbit and nearly all space missions orbit.From this vantage point 24 degrees above the ecliptic, Solar Orbiter acquires a top-down view of the Sun and captures the first-ever images of the Sun’s north and south poles. Its suite of 10 instruments document the never-before-observed magnetic environment there — key to understanding the Sun’s 11-year solar cycle and its periodic outpouring of solar storms.

Caption: An animation of Solar Orbiter peering at the Sun through peepholes in its heat shield. Credit: ESA/ATG medialab


By Miles Hatfield
NASA’s Goddard Space Flight Center, Greenbelt, Md.

48 thoughts on “A Solar Science Timeline – sunspots, cycles, and solar wind

    • Generally very good. Concise and simple while avoiding the typical condescending language ( for the most part ).

      “On April 17, 1976, Helios 2 becomes the first spacecraft to enter inside the orbit of Mercury, traveling as close at 26.55 million miles to the Sun”

      seems to be some confusion with the later Parker probe.

      “The ESA/NASA Solar Orbiter mission launches on a path out of the ecliptic plane”
      No date so I assume it has not happened yet. Scheduled for Fed 7 !!

      ” Its suite of 10 instruments document the never-before-observed magnetic environment there ”
      Reporting what he hopes will happen in the future as though it is already recorded history. So sure of themselves they are already writing the book. Not at all scientific !

      • Greg,
        Parker went closer on 29 October 2018 – but Helios 2 was first – in 1976! to get closer than Mercury.
        “On April 17, 1976, Helios 2 becomes the first spacecraft to enter inside the orbit of Mercury, traveling as close at 26.55 million miles to the Sun”

        seems to be some confusion with the later Parker probe.

  1. Anthony –

    Outstanding overview! Quite concise. All the high points.

    A similar one on anthropomorphic climate change theory would be much appreciated.

    • Greg February 5, 2020 at 9:21 am

      Still no idea how the corona can be so much hotter than the photosphere then.

      Greg, the corona is the Sun’s “atmosphere”.

      The sunspots are “robbed” of energy by sustained coronal mass ejection.

  2. Great reference!
    Perhaps following may be of some interest to readers:
    Ancient Egypt’s pharaoh Akhenaten abolished polytheism and introduced monotheistic religious worship of god Aten “sun disk” as described on numerous cartouches. In illustrations (of himself alone or with his wife Nefertiti and his son Tutankhamun) he is always shown in presence of solar disk. Is Akhenaten, here shown as a sphinx, ‘taking notes’ of the solar disk’s appearance noting presence/absence of the sunspot activity
    https://ancientegyptonline.co.uk/wp-content/uploads/2019/04/akhenaten-sphinx.jpg

    NASA Finds Sun-Climate Connection in Old Nile Records
    The researchers found some clear links between the sun’s activity and climate variations. The Nile water levels and aurora records had two somewhat regularly occurring variations in common – one with a period of about 88 years and the second with a period of about 200 years.
    “Since the time of the pharaohs, the water levels of the Nile were accurately measured, since they were critically important for agriculture and the preservation of temples in Egypt,” said Dr. Joan Feynman (yes, the sister of the more famous brother Richard) from the NASA’s Jet Propulsion Laboratory.
    https://www.jpl.nasa.gov/news/news.php?feature=1319
    Now, you may hear from people who will dispute whole thing, but as they say “you pays your money and you takes your choice”
    Free access Feynman’s paper is here:
    https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2006JD007462

    • Proposed mechanism (from the above paper):
      “On the basis of this finding we suggest the following possible link between solar variability and the Nile: (1) Solar UV variations act in the stratosphere to modulate the Northern Annular Mode (NAM); (2) The NAM’s sea level manifestation (NAO) affects the air circulation over Atlantic and the Indian Oceans during high levels of solar activity; (3) Variations of this air circulation influence rainfall in eastern equatorial Africa at the Nile sources. At high solar activity, the air is descending there and conditions are drier, with the opposite effect occurring at low solar activity. Further investigations of this link will shed more light on the connection between the Sun’s variability and the Nile.”

  3. In paragraph for last dated event, February 2020, this text: “From this vantage point 24 degrees above the ecliptic, Solar Orbiter acquires a top-down view of the Sun and captures the first-ever images of the Sun’s north and south poles.”

    Clarification needed: with an observatory spacecraft in an solar-“centered” orbital plane inclined 24 degrees to the plane of the ecliptic, it is not possible to obtain a “top-down view of the Sun”, although each pole can be viewed at a oblique angle. The initial orbital plane will be inclined only 24 degrees from the ecliptic, but plans are to increase it to 33 degrees inclination if the mission continues into its “extended life” phase. An orbital inclination of 90 degrees would be required for a true “top-down” views of the Sun’s (inertial, not magnetic) north and south poles.

    BTW, the first launch opportunity for Solar Observed from Cape Canaveral is Feb. 7, 2020, at 11:15 p.m. EST (ref: https://www.nasa.gov/feature/goddard/2020/new-mission-will-take-first-peek-at-sun-s-poles ).

    • Sorry . . . my last sentence should have referenced launch of Solar Orbiter, not launch of Solar Observer (with typo).

  4. “Over the following decade, Hale and colleagues discover that the changing number of sunspots reflects a larger magnetic process on the Sun known as the solar cycle. Every 22 years — twice the length of the sunspot cycle — the magnetic polarity of the Sun reverses. North becomes south, and vice versa.”

    The N-S polarity reverses at every 11 year cycle near maximum.
    A 180º magnetic pole flip every 11 years. It just takes 22 years for the magnetic flip cycle to to go the full 360º.

  5. Space weather and the solar-driven wind are extremely important to understand. Sadly, NASA’s orignally formed group to do that, GISS, got side-tracked by Hansen into an environmental agenda in 1980’s.

  6. I miss Dr. Svalgaard’s contributions on these subjects. I wonder why he no longer visits. I’d be interested in his opinions on the Parker mission.

  7. Anthony , You may like to add this to your timeline.

    “For three years the SAFIRE Project team has been holding back so as not to overstate what has been happening in the SAFIRE lab. The SAFIRE Project is now able to make a number of definitive statements supported by concrete evidence, statements about: energy production; transmutation/creation of elements; remediation of radioactive materials; and the sun and interstellar medium”

        • Thanks for the link. I was able to download some of the material, namely the three “smaller” presentations, which I could get in pdf form via the “save linked content” option. None of these are over 100MB in size.

          However, no such option was offered by my browser for the “90 minute” presentation, and the instructions on the website seem to suggest one must first load it into the browser and then download it.

          It appears to be in pdf format, but I was never able to load it completely. OTOH, another presentation, apparently a 2019 overview, loaded fairly quickly and ran, and it appears to be 1 hour and 28 minutes long…

          It’s not clear to me exactly how many distinct articles are available on the site. And I can only hope the “latest” will still be available when I have more time to watch it. It would be nice to have a written resume, at least , of this update.

  8. “English astronomer Sir Arthur Eddington observes starlight bending around the Sun’s limb during a solar eclipse. The observations confirm a key prediction of the theory of General Relativity. The theory’s creator, a physicist named Albert Einstein, becomes world famous overnight.”

    did eddington ever get poppers memo

    popper

    http://fakenous.net/?p=1239

    “You probably associate Popper with these ideas: It’s impossible to verify a theory, with any number of observations. Yet a single observation can refute a theory. Also, science is mainly about trying to refute theories. The way science proceeds is that you start with a hypothesis, deduce some observational predictions, and then see whether those predictions are correct. You start with the ones that you think are most likely to be wrong, because you’re trying to falsify the theory. Theories that can’t in principle be falsified are bad. Theories that could have been falsified but have survived lots of attempts to falsify them are good.

    I wrote that vaguely enough that it’s kind of what Popper said. And you might basically agree with the above, without being insane. But the above paragraph is vague and ambiguous, and it leaves out the insane basics of Popper’s philosophy. If you know a little bit about him, there is a good chance that you completely missed the insane part.

    The insane part starts with “deductivism”: the view that the only legitimate kind of reasoning is deduction. Induction is completely worthless; probabilistic reasoning is worthless.

    If you know a little about Popper, you probably think he said that we can never be absolutely certain of a scientific theory. No, that’s not his point (nor was it Hume’s point). His point is that there is not the slightest reason to think that any scientific theory is true, or close to true, or likely to be true, or anything else at all in this neighborhood that a normal person might want to say.”

    back to eddington. The story is fascinating with respects to what data got thrown out, by whom and why
    Yup, some data got tossed.

    https://ui.adsabs.harvard.edu/abs/2017AAS…23011903S/abstract

    https://arxiv.org/ftp/arxiv/papers/0709/0709.0685.pdf

    • there is not the slightest reason to think that any scientific theory is true, or close to true, or likely to be true

      Tell that to the climate hysterics among whom you camp.

      • I think you may have misunderstood Mr. Mosher. The quoted sentence is his version of the “insane” views of Popper which he is denouncing, not his own position.

    • It’s not obvious what occasioned this rant against Popper, especially when discussing the corroboration by observation of Einstein’s theory, a classic example of Popperian methodology in action. Popper considered that observations could show that one theory was better than another, “better” in the sense of being closer to the truth (having what he called greater verisimilitude). To those who want to find out more about Popper’s views, as opposed to Mr. Mosher’s misunderstanding of them, I recommend to begin with reading Popper’s book, Realism and the Aim of Science. It’s true that normal people may often find Hume’s denial of the logical validity of induction, agreed to by Popper, to be “insane”, but then, normal people find many things we take seriously (such as some implications of quantum mechanics) to be insane. It’s not a promising idea to poll normal people to settle questions in epistemology or any other branch of philosophy. Normal people typically believe a lot of crap.

  9. Anthony

    Vuk
    In 1974 astronomer Barbara Bell published her work on climate change and a succession of poorer harvests for the Nile. This prompted political change in Ancient Egypt.
    Of course, the governing classes would live well during the times when ordinary folk were hard=pressed.
    As Bell wrote it up, the difference provoked popular uprisings.
    One key of which was that the palace guards were “of the people”. And when push came to shove they would lay down their spears and –suddenly–there was interregnum and dynastic change.
    I’ve referred to her work for a long time.
    And in 1989 was delighted to see East German border guards lay down their machine guns.
    So that ordinary Germans could go cross-border shopping for groceries.

  10. “English astronomer Sir Arthur Eddington observes starlight bending around the Sun’s limb during a solar eclipse.” Supposedly that confirms Einstein’s General Relativity.

    But does it?

    There is an atmosphere around the Sun, it’s called the corona.

    Light will bend as it passes through a substance. The old high school experiment of putting a stick in a bucket of water and the stick appears to bend. So, the light of a star can appear to bend as it passes through the atmosphere of the Sun.

    Eddington is the source of much confusion regarding the properties of the Sun. Most if not all of Eddington’s ideas, which were based on observations with limited equipment (telescopes) have been shown to be inconsistent with the more detailed observations & measurements of today.

    Yet, with scientific inertia, Eddington’s ideas of nearly a century ago, still hold sway.

    • “Light will bend as it passes through a substance. The old high school experiment of putting a stick in a bucket of water and the stick appears to bend. So, the light of a star can appear to bend as it passes through the atmosphere of the Sun.”

      Travers vector of light in that case really is bent so the light passes a longer way – in the same time as the “unbent” vector. There’s a time limit for traversing: the speed of light.

  11. Eddington’s observations confirming Relativity Theory seems to be a textbook case of confirmation bias. Many are of the view that his equipment was simply not up to the task and the conditions they made the observations under were pretty awful. The resolution was far too poor to detect the very small shifts so Eddington had to make some guestimates. He was an avid believer in the theory and he was not to to travel all that way and not come back with something!
    His observations did not invalidate the theory but neither do they validate it.

    • Eddington’s results have been repeatedly confirmed and never falsified, in light and radio frequencies.

      In this century, Eddington’s own observations and calculations have likewise been confirmed with modern techniques.

      Gravity bends light. It’s a fact, ie an observation of nature.

      • John Tillman , Get over yourself, move forward and grow. Why do you want to hold onto an old out dated theory ???? To create change in your life , first you have to stop thinking the way your thinking and only then you can move forward, or are you to set in your ways to change???
        Wal Thornhill: Big Bang – Time to Wipe the Chalkboard Clean | Space News

  12. traveling as close at 26.55 million miles to the Sun –> traveling as close as 26.55 million miles to the Sun

    / Yep, doesn’t really move the needle

  13. Correct me where I’m wrong –

    NASA’s Wind spacecraft launches.

    Wind first travels to the L1 lagrange point, outside Earth’s protective magnetic field between the Sun and Earth, then moves to L2, on the other side of Earth –> Wind spacecraft first travels to the L1 lagrange point, outside Earth’s protective magnetic field between the Sun and Earth, then moves to L2, on the other side of Earth

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