February 2022 — News is the remains of the scuttled ship Endeavour, commanded by Lt. James Cook, have been discovered in Newport Harbor, Rhode Island, where they lay for more than 200 years. The ship sailed to Tahiti to observe the June 3, 1769 transit of Venus. Endeavour was, of course, involved in far broader explorations of the South Pacific, but the news of her discovery reminded me of my own experience: the June 5, 2015 transit of Venus — observed 246 years after Cook — from Hiram at a public event we hosted.
James Cook’s sketch of the “Black Drop” Effect observed as Venus began its transit of the solar disk.
Recalling that day, the afternoon was cloudy and rainy and I thought we would miss out. But mere minutes before the silhouette of Venus was to appear on Sun’s face mists faded, clouds parted, and Sun shined brightly. I quickly finished setting up the telescopes, peered through the eyepiece to focus, and saw the same “black drop” phenomenon Cook sketched. My camera was set up too late (due to the aforementioned weather) to record the “black drop” for later sharing.
June 5, 2012 Transit of Venus photographed by James Guilford
We hosted visitors at our mobile telescope site — the former location of Hiram Elementary School — until Sun sank below the treeline to our west, the transit still in progress. In the end more than 100 (estimated count lost) men, women, and children saw that big black dot moving across the sun. It was a lovely experience.
A transit of Venus is the passage of the planet across the face of our Sun as seen from Earth. Transits of Venus are rare; they come in pairs, 8 years apart, separated by approximately 120 years. Our next opportunity comes in December 2117. See you then?
The Sun, showing several sunspots/active regions. This image was made at 3:43 PM EDT/7:43 PM UTC on September 10, 2021 using the photographer’s personal reflecting telescope with safe solar filter, and DSLR camera body. Credit: James Guilford
After a long period of quiet during our Sun’s fairly predictable 11-year activity cycle, things have been happening. What was a bright, clear disk has become speckled with sunspots of late. The increased activity brings with it the chance of Earth-directed coronal mass ejections, or CMEs, which result in solar storms when they collide with our home planet’s magnetic field. Auroras, or “northern lights” for us, are one potential result of solar storms. The less pleasant effects can include disruption of radio communications and satellite operation, all the way to electrical grid failures at the extreme!
Several recent CMEs have missed Earth but one is headed in our direction as this blog entry is being written. According to SpaceWeather.com, “{A} CME is on the way following an explosion in the magnetic canopy of sunspot AR2864 on Sept. 8th. NOAA analysts believe Earth could experience a glancing blow or near miss late on Sept. 11th.” Those favored with clear skies and a good view to the north may want to be on the lookout for aurora, but the odds aren’t favorable … this time!
Here are two photos of Sun, shot by Stephens’ Director James Guilford, at 3:43 PM EDT (7:43 PM UTC). The first image shows the full solar disk. Notice not only the dark sunspots but also the lighter-colored “splotches” of additional active solar regions, most visible near the edges of the disk.
The second image is cropped to show the major concentration of the day’s sunspots with their official numerical designations. Both images have been color tinted.
A tightly-cropped portion of the day’s full-disk image shows three sunspot groups: AR 2866, AR 2868, and AR 2869. Sunspots only appear to be dark because they are significantly “cooler” than the surrounding solar atmosphere; they are actually quite hot. Sun’s shining photosphere has a temperature of 5,800 degrees Kelvin while sunspots have temperatures of around 3,800ºK (6,380℉). Nearly all of the dark features seen here are larger than planet Earth. Credit: James Guilford
An annular eclipse of the sun will take place June 10 and it will be underway at sunrise. Unfortunately, even with clear skies we will not see the “ring of fire” that is the namesake look of this type of eclipse. In fact, no place in the United States will see the complete circle, or annulus, of Sun around Moon. So don’t feel left out.
In our area, sunrise will be at 5:55 AM (EDT) with the eclipse already at its maximum for us. The eclipse ends at 6:35 AM as Moon completes its passage across Sun.
A total eclipse of the sun takes place when Earth’s Moon, at normal orbital distances, covers the solar disk completely and blocks all but the glowing corona from view. An annular eclipse takes place when Moon is at higher points in its orbit when it passes between Earth and Sun, too distant and small to form a perfect cover, allowing a brilliant ring of our star to shine.
What we may see at dawn and diminishing thereafter, is a partial solar eclipse — looking a bit like the chomping character from the classic PAC-MAN video game. Much of the solar disk will be visible but the curved edge of Moon will take a bite out of one side.
How can you watch the eclipse? With great care!
Partial Eclipse of the Sun, August 21, 2017 — this image rotated to resemble what viewers might see at dawn, June 10, 2021. Photo by James Guilford
How can you watch the eclipse? With great care! At no time during our partial solar eclipse will it be safe to watch the event without vision protection. If you have eclipse glasses from a recent solar eclipse, those should be just fine — just make sure there are no pinholes or other damage to the plastic film “lenses”! You can check for damage by holding the eclipse viewer at arm’s length and looking at a bright lightbulb. If you see any dots of light through the viewer film, throw those glasses out!
Do NOT look at the sun through sunglasses, even multiple sets of sunglasses, or photo negatives, Compact Discs, or anything other than certified eclipse viewing equipment! Pinhole and other projection techniques can be used safely since the viewer is looking at a projection and not the sun itself. Five Ways to View the Solar Eclipse
“The Sun can be viewed safely with the naked eye only during the few brief seconds or minutes of a total solar eclipse. Partial eclipses, annular eclipses, and the partial phases of total eclipses are never safe to watch without taking special precautions. Even when 99% of the Sun’s surface is obscured during the partial phases of a total eclipse, the remaining photospheric crescent is intensely bright and cannot be viewed safely without eye protection [Chou, 1981; Marsh, 1982]. Do not attempt to observe the partial or annular phases of any eclipse with the naked eye. Failure to use appropriate filtration may result in permanent eye damage or blindness!” — NASA: Eye Safety During Solar Eclipses
The corona, a region of the Sun only seen from Earth when the Moon blocks out the Sun’s bright face during total solar eclipses. The corona holds the answers to many of scientists’ outstanding questions about the Sun’s activity and processes. This photo was taken during the total solar eclipse on Aug. 21, 2017. Credits: NASA/Gopalswamy
Be sure to be watching July 2 at 4:00 PM EDT as the total solar eclipse is presented live from Chile, via San Francisco’s Exploratorium. You will not be able to directly see the eclipse from the USA; the total solar eclipse will be visible from a narrow part of the South Pacific Ocean, Chile, and Argentina.
The Exploratorium will be bringing the total solar eclipse to you, no matter where you are. The have sent a team to Chile to broadcast from within the path of totality. Enjoy this full, unnarrated view of the eclipse from the telescopes at the National Science Foundation’s Cerro Tololo Observatory.
NASA has partnered with the Exploratorium to provide the coverage which it will livestream: three views via separate players on the agency’s website (all times EDT):
Live views from telescopes in Vicuna, Chile, without audio, from 3 to 6 PM
A one-hour program with live commentary in English, from 4 to 5 PM
A one-hour program with live commentary in Spanish, from 4 to 5 PM
This illustration shows the position of NASA’s Voyager 1 and Voyager 2 probes, outside of the heliosphere, a protective bubble created by the Sun that extends well past the orbit of Pluto. Credits: NASA/JPL-Caltech
For the second time in history, a human-made object has reached the space between the stars. NASA’s Voyager 2 probe now has exited the heliosphere – the protective bubble of particles and magnetic fields created by the Sun.
Comparing data from different instruments aboard the trailblazing spacecraft, mission scientists determined the probe crossed the outer edge of the heliosphere on Nov. 5. This boundary, called the heliopause, is where the tenuous, hot solar wind meets the cold, dense interstellar medium. Its twin, Voyager 1, crossed this boundary in 2012, but Voyager 2 carries a working instrument that will provide first-of-its-kind observations of the nature of this gateway into interstellar space.
Voyager 2 now is slightly more than 11 billion miles (18 billion kilometers) from Earth. Mission operators still can communicate with Voyager 2 as it enters this new phase of its journey, but information – moving at the speed of light – takes about 16.5 hours to travel from the spacecraft to Earth. By comparison, light traveling from the Sun takes about eight minutes to reach Earth.
The most compelling evidence of Voyager 2’s exit from the heliosphere came from its onboard Plasma Science Experiment (PLS), an instrument that stopped working on Voyager 1 in 1980, long before that probe crossed the heliopause. Until recently, the space surrounding Voyager 2 was filled predominantly with plasma flowing out from our Sun. This outflow, called the solar wind, creates a bubble – the heliosphere – that envelopes the planets in our solar system. The PLS uses the electrical current of the plasma to detect the speed, density, temperature, pressure and flux of the solar wind. The PLS aboard Voyager 2 observed a steep decline in the speed of the solar wind particles on Nov. 5. Since that date, the plasma instrument has observed no solar wind flow in the environment around Voyager 2, which makes mission scientists confident the probe has left the heliosphere.
“Working on Voyager makes me feel like an explorer, because everything we’re seeing is new,” said John Richardson, principal investigator for the PLS instrument and a principal research scientist at the Massachusetts Institute of Technology in Cambridge. “Even though Voyager 1 crossed the heliopause in 2012, it did so at a different place and a different time, and without the PLS data. So we’re still seeing things that no one has seen before.”
In addition to the plasma data, Voyager’s science team members have seen evidence from three other onboard instruments – the cosmic ray subsystem, the low energy charged particle instrument and the magnetometer – that is consistent with the conclusion that Voyager 2 has crossed the heliopause. Voyager’s team members are eager to continue to study the data from these other onboard instruments to get a clearer picture of the environment through which Voyager 2 is traveling.
“There is still a lot to learn about the region of interstellar space immediately beyond the heliopause,” said Ed Stone, Voyager project scientist based at Caltech in Pasadena, California.
“Voyager has a very special place for us in our heliophysics fleet,” said Nicola Fox, director of the Heliophysics Division at NASA Headquarters. “Our studies start at the Sun and extend out to everything the solar wind touches. To have the Voyagers sending back information about the edge of the Sun’s influence gives us an unprecedented glimpse of truly uncharted territory.”
While the probes have left the heliosphere, Voyager 1 and Voyager 2 have not yet left the solar system, and won’t be leaving anytime soon. The boundary of the solar system is considered to be beyond the outer edge of the Oort Cloud, a collection of small objects that are still under the influence of the Sun’s gravity. The width of the Oort Cloud is not known precisely, but it is estimated to begin at about 1,000 astronomical units (AU) from the Sun and to extend to about 100,000 AU. One AU is the distance from the Sun to Earth. It will take about 300 years for Voyager 2 to reach the inner edge of the Oort Cloud and possibly 30,000 years to fly beyond it.
The partial solar eclipse reaches its maximum at 2:23 PM EDT as viewed from Hiram College, Hiram, Ohio
On Monday, August 21 millions gathered along a thin path crossing the United States to watch a total eclipse of the Sun, the first to cross the continent since June 1918. Those with favorable viewing conditions along the path of totality enjoyed a truly amazing sight and experience; a total solar eclipse is truly awe-inspiring. From Northern Ohio, outside of the eclipse path, 80 percent of the solar disk would be covered by the Moon. Public interest in the event was high and so we hosted the Hiram Eclipse Watch
Watching and Waiting for the Big Event – Credit: James Guilford
We estimate at least 375 people came to the campus lawn to share nature’s show and enjoy the sight together. Some families brought blankets and had picnic lunch in the shade of trees while waiting for the eclipse to begin. Driven by media reports, demand for Sun-safe eclipse viewing glasses was tremendous. Hiram had 300 eclipse viewers available for free distribution and even with restriction to one viewer per family or group, we ran out of glasses long before the eclipse ended. The offer of free eclipse glasses did, however, encourage some of our attendees to come out to Hiram College and discover there was more to enjoy than a giveaway; the view through our telescopes was tremendous.
Woman watches eclipse through specially-equipped telescope. Credit: Dave Dreimiller
Three telescopes offered safe views of the eclipsing Sun three different ways. One scope employed a glass filter with metal compounds that absorbed the Sun’s dangerous radiation and presented an orange-tinted image. The largest telescope present, a six-inch refractor, was outfitted with a modern version of the Herschel Wedge; that telescope focussed unfiltered light into the wedge which, in turn, deflected all but a small amount of light with a green tint and offered tack-sharp viewing of the disappearing Sun, sunspots, and granulation texture in the solar atmosphere. A third instrument was a telescope specifically made to view the Sun only hydrogen alpha (Ha) light. Ideally, an Ha scope will show details of the solar atmosphere invisible to those using other methods, and include solar prominences — geysers of plasma arcing high above the Sun — but none were seen this day.
Watching the Eclipse with Safety Glasses – Credit: Dave Dreimiller
People of all description came and went during the event though most stayed until the maximum eclipse had been reached and the Moon began to recede from Sun. Lines of folks waited patiently to see the telescopic views, even attempting smart phone photos; there were many repeat views, observing the progress of the eclipse with each fresh look. We estimate at more than 375 people came to the campus lawn to share nature’s show and enjoy the sight together.
Solar Telescopes Trained on the Eclipse – Credit: Dave Dreimiller
There was learning, and laughter, and a fine day shared under Sun and Moon. It may not have been a total eclipse for those watching from Hiram College, but it was a total pleasure.
Before Maximum Eclipse – Credit: James Guilford
Cooperative weather plus plenty of happy and excited people made the afternoon a wonderful occasion sharing a fine day featuring a dance by the Sun and Moon.
Before Maximum – Rough Edge. Look closely along the dark curve of the Moon moving over the Sun and note “bumps” along the edge: the silhouettes of craters and mountains on the Moon.
The (Ravenna) Record-Courier made it front-page news!
Path of the August 21, 2017 Total Solar Eclipse – Courtesy NationalEclipse.com
Planning is underway for a public event celebrating the upcoming August 21, 2017 solar eclipse. The eclipse will begin at 1:07 PM and end at 3:52 PM Eastern Daylight Time. Maximum eclipse will occur locally at about 2:30 PM EDT. Details are developing but the Hiram Eclipse Watch will take place on the Hiram College campus and will be free and open to the general public — everyone’s invited!
The so-called “American Eclipse” or “National Eclipse” will be a total solar eclipse (Moon covering the entire solar disk) only for those situated on a relatively narrow path stretching from the Pacific Northwest to South Carolina and the Atlantic. For the balance of the Continental United States, the eclipse will be partial — the Moon will cover only part of the Sun. Northern Ohioans will see a bit more than 80 percent of the Sun covered by the Moon reducing the Sun to a brilliant crescent!
We have created and are regularly updating a page on this website dedicated to Hiram’s eclipse event; check there for event details as they develop. We hope to see you August 21 for a fun and memorable experience.
To reach our Eclipse Watch page see the menu at the top of this page, or click here!
Mercury’s Transit in Progress: Mercury is the tiny dot at the lower-left. Smudge near the center is a group of sunspots. Photo by James Guilford.
Our Solar System doesn’t care about the local weather. When something rare and interesting like today’s transit of Mercury across the solar disk takes place, it happens and there are no “rain checks.” And so it was this morning when the day dawned clear to partly-cloudy allowing us to glimpse the beginning of Mercury’s trek only to have the show stopped by rapidly encroaching clouds progressing to solid overcast!
Transit of Mercury: Mother Earth’s atmospherics begin to block the view! Photo by James Guilford.
At the predicted hour Mercury appeared as a tiny dot, silhouetted in the lower left-hand quadrant of the Sun’s bright disk. Using special protective filters, observers on the ground watched as the small dot slowly moved inward from Sol’s limb. Here in Northern Ohio, transit watchers were treated to the beginning of the show. Much of the nation missed out entirely, cloud cover already in place at dawn!
Weather Satellite Image: Much of the US cloud-covered during the transit event.
NASA’s Solar Dynamics Observatory, a spacecraft, is unaffected by Earth’s pesky atmospherics and its technology produces some very dramatic images. One of my favorites shows Mercury about to cross between the satellite (us) and the Sun’s glowing photosphere; the planet has the active solar atmosphere as backdrop. Planet Mercury is 3,030 miles in diameter, not much bigger than Earth’s Moon, and looked every bit as tiny as it is compared with our nearest star!
The View from Space. Credit: Data courtesy of NASA/SDO, HMI, and AIA science teams.
Today’s transit of Mercury took place over several hours. For us in Northern Ohio, the transit began at about 7:12 AM Eastern Daylight Time with the Sun barely up. Midpoint of Mercury’s passage was at 10:57 AM, and the transit ended at 2:42 PM. Because of the orbital inclinations of the inner planets, the alignment needed to produce a transit of Mercury happens only about 13 times per century making even a glimpse of the event something special. After today’s, the next transits of Mercury will take place in November 2019, November 2032, and November 2049.
At least we won’t have to wait for so long as we must for the next transit of Venus — that happens in December 2117.
On Monday, May 9 solar observers in North America will be able to see the silhouette of planet Mercury as it passes between Earth and our Sun. The event, called a transit, is relatively rare — though not so rare as a transit of Venus — and may cause interest in viewing the Sun. WARNING: Looking at the Sun, especially through optical instruments, requires extreme caution! Permanent vision damage can result if proper precautions are not taken! Click here for a good article on safely observing the Sun.
At present we DO NOT plan to open Stephens Observatory for the transit but if plans change, the announcement will be made here — check back later. If conditions are clear, we hope to post images made via telescope at a remote location.
Tiny planet Mercury will appear as a correspondingly tiny black dot against the Sun’s brilliant disk. If any sunspots are present on Sol’s face, compare them with Mercury: the planet will be distinctly round and noticeably darker than sunspots, and from minute to minute it will move — sunspot motion takes days!
May 9 Transit of Mercury – Note how the orbits of Mercury, Venus, and Earth are “tilted” making line-of-sight alignment a rare occurrence.
Viewed from Earth, transits occur when one of the inner planets crosses the line of sight between our world and the Sun; only Venus and Mercury are ever able to do that. A transit, then, is a bit like a solar eclipse only viewed at a greater distance and blocking only a small amount of the Sun’s light.
Transits would occur more often but for the fact that the orbits of Mercury and Venus are “tipped” so that they do not align along the same plane as Earth’s path. Only when the planets are in the right position where the line of sight passes straight through to the Sun do we see transits and with Mercury, that happens only about 13 times per century. After May 9, the next transits of Mercury will take place in November 2019, November 2032, and November 2049. The most recent transit of Venus took place in June 2012 and will not be seen again until December 2117.
Monday’s transit of Mercury will take place over several hours. For us in Northern Ohio, the transit begins at about 7:12 AM Eastern Daylight Time with the Sun low in the east. Midpoint of Mercury’s passage will be at 10:57 AM, and the transit ends at 2:42 PM.
Cloudy skies? Don’t have proper gear to view the Sun? Fret not! There will be “live” webcasts of the event from various sources during Mercury’s passage. Use your favorite web search engine to find good sources and check for a planned broadcast via NASA TV. NASA will stream a live program on NASA TV and the agency’s Facebook page from 10:30 to 11:30 AM — an informal roundtable during which experts representing planetary, heliophysics and astrophysics will discuss the science behind the Mercury transit. Viewers can ask questions via Facebook and Twitter using #AskNASA.
Changing a word from an old song lyric by The Police, there’s a big black spot on the Sun today. Sunspot AR2529 is the dominant feature on our otherwise quiet star. Visible to the unaided eye through solar-safe filters, the sunspot is several Earth-diameters across and roughly “heart” shaped! This image was recorded Wednesday, April 13, at 2:19 PM. The bright orange color resulted from use of a solar filter covering the camera lens.
Here is what SpaceWeather.com says about the sunspot: “Since it appeared less than a week ago, AR2529 has been mostly, but not completely, quiet. On April 10th it hurled a minor CME into space. That CME, along with another that occurred a few hours later, could deliver a glancing blow to Earth’s magnetic field on April 13th.” A CME is a Coronal Mass Ejection wherein the Sun flings plasma from its atmosphere out and into space. CMEs reaching Earth can cause auroras.
Photo (above) Info: Cropped from full frame, Canon EOS M3: ISO 250, 1/1600 sec., f/8, 400mm lens. Photo by James Guilford. Photo (below) Info: Canon EOS 6D: ISO 400, f/4, 1/1250 sec., observatory telescope afocal technique.
Sunspot AR2529 – April 14 – Through the Vintage Cooley Telescope
Stephens Memorial Observatory 