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.
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.
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
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.
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.
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.
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.
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.
The (Ravenna) Record-Courier made it front-page news!
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!
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!
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!
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!
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!
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.
An impressive train of sunspots has been making its way across the face of our nearest star this week. In the photo above: Designated AR2447 (small group to the left), AR2443 (bigger and darker, near center), and AR2445 (far right), the “Active Regions” have the potential of unleashing flares. In fact, AR2445 was the source of a flare that caused this week’s “northern lights” sighted across northern latitude locations around the world. Now rotating over the Sun’s limb, AR2445 won’t be aimed at Earth for a while — if ever again — but AR2443 has potential for high-energy flares.
Photo credit: James Guilford. Canon EOS 7D II: ISO 400, f/11, 1/1250 sec., 400mm lens with Astrozap film solar filter, heavily cropped, November 4, 2015, 2:22 PM.
Preparing for this week’s expected heavy rains and wind, I went to the roof of the observatory to clean out the rain gutters and check the downspouts. Chores done and with the dome open, I made another experiment at solar imaging through the big vintage Cooley Telescope. I found I could focus on the Sun (through a safe solar filter) and, with a Canon DSLR camera at the telescope’s prime focus, recorded a few one-shot images at ISO 400 and 1/500 second. The telescope is a 9-inch refractor with a focal length of 3,327mm. The results appear better than last time but show the apparent effect of atmospheric turbulence: that’s my story and I’m sticking with it! A few sunspots were visible and details of Sol’s roiling atmosphere show up. The photographic technique is the simplest we can use; more sophisticated processes are employed these days to achieve best results. Still, proof of concept is a good thing and getting the image focused is a critical step. I think next time we may try a dimmer subject.
Testing out a modified eyepiece adapter today, I had the vintage Cooley Telescope pointed at the Sun. Since everything was set up, I decided to see whether we could capture decent images of our nearest star, near noon on this clear summer day. While the sky was clear, the seeing — quality of the view — was not as good as I’d hoped. Apparently, midday heat was causing the image to “shimmer” in the eyepiece and the photographs reflected that. Examining the pictures on the computer screen, I was disappointed because I saw no details in the several sunspots visible. As I made some photographic adjustments, however, other features came into view: granulation and faculae! The granules, upwelling super-hot cells of solar atmosphere, are easy to see; they give the image above a “grainy” appearance. Faculae are a bit trickier but if you look along the darker right-hand edge of the solar image, you will see some light-colored patches — those patches are faculae! So a bit of disappointment changed to a sunny day surprise.
NOTES: Sunspots in this image are #2387 (L) and #2386 (R). For more information on the Sun’s photosphere and what can be seen there, visit this page at NASA/ Marshall Space Flight Center.