Total solar eclipse – Idaho, USA – 21 August 2017

In August 2017 I was the guest astronomer on an Omega Holidays trip to observe the total solar eclipse from Idaho, USA. Below is a brief photo report from that trip – images of totality begin about half way down.

An image of the solar corona during the 21 August TSE made from 5 separate exposures composited using the method described here. Credit: Will Gater

Full eclipse sequence from first to fourth contact (click image for larger version). Credit: Will Gater. All images below by Will unless otherwise stated.

Our trip began in Salt Lake City, Utah, from where we headed north across the border into Idaho and the town of Pocatello. Our hotel there would be the group’s base for the next two days and on the evening of our arrival I presented a welcome talk on the solar eclipse, what we could expect to see and our plans for getting to our chosen observing site. Already there was great excitement about what lay ahead in the coming 48 hours and the latest weather forecasts showed that we would be in with a good chance of seeing the eclipse, providing that a narrow band of high cloud that was showing up in the forecast models moved far enough south by the time of first contact.

The next day we ventured northwest of Pocatello — entering the path of totality for the first time — for a day trip to the Craters of the Moon National Monument. This extraordinary volcanic landscape really did seem alien, and indeed it was here that NASA brought some of the Apollo astronauts for geology training prior to their lunar missions.

From some viewpoints the landscape was uncannily Moon-like. This hill (below) in particular reminded me of the enormous mountains encircling the Taurus-Littrow valley visited by the Apollo 17 mission.

A close-up shot of the ground at Craters of the Moon, made up of a light, glassy volcanic material which caught the sun and in places appeared iridescent.

In the days leading up to the eclipse we encountered overhead road signs throughout Idaho and Salt Lake City warning of eclipse-related traffic. Thankfully though, and contrary to a number of predictions, the roads in the days before the eclipse seemed rather quiet if anything, and we had absolutely no trouble getting about in the coach. That would change after the eclipse ended though!

Similarly, we didn’t see or experience any of the forecasted pre-eclipse panic buying or shops/gas stations without food and supplies. In fact, as the pictures below show, local stores were well-prepared and well-stocked for the event. Local and network television news programmes were even reporting that some hotels still had rooms available and, according to one broadcast, some eateries in the eclipse path were seeing markedly low numbers compared to previous summers. Were people scared away by warnings of chaos? Quite possibly. Certainly the atmosphere pre-eclipse felt very similar to that in the West Country in the years preceding the 1999 total solar eclipse.

As eclipse-eve arrived I stood outside our Pocatello hotel watching the Sun set into a large band of thick, high cloud drifting in from the northwest (just as forecast). And, once again, I found myself wondering if that cloud would be far enough to the south by the next morning to give us clear skies. The pre-eclipse-day nerves were enhanced further still after hearing that a 50-acre wildfire had broken out earlier that evening near our planned observing site. Mercifully no one was hurt and the amazing local fire-fighting teams had the wildfire contained by the late evening; in fact, we would later learn that the fire itself was actually some way from the site. Still, with that, the cloud lingering in my mind and the checking and double-checking of all my camera batteries, adaptors and equipment I got very little sleep.

One of the things that was also making me nervous was that in Pocatello we weren’t actually in the path of the Moon’s umbral shadow i.e. we wouldn’t be able to see a total eclipse from there. The plan was that on the morning of the eclipse we would leave the hotel and drive north in our bus to a specially chosen observing site (which was in the zone of totality) at the North Menan Butte, a spectacular volcanic ‘tuff cone’ rising out of the Snake River Plain. But of course no one knew exactly what the traffic situation would be on the morning, so we planned to leave at 5am, giving us just under five hours to do what should be a 1hr10m trip.

When I stepped out of the hotel lobby at 4:30am on the 21st the air was refreshingly cool. The interstate going north past the hotel had a good number of cars on it — at least for that time in the morning I thought — but it was moving quickly. What’s more, there were several stars visible through the glare of the nearby streetlights. Had the sky cleared enough overnight? We’d have to wait for daybreak to know for sure.

The location of our observing site (yellow arrow). Credit: NASA’s Scientific Visualization Studio. The Blue Marble data is courtesy of Reto Stockli (NASA/GSFC).

Right on schedule, at 5am, our 50-strong group boarded the bus and we began the journey north in high spirits. At about 5:40am — near the town of Shelley, south of Idaho Falls — I announced that we had, just that moment, crossed into the path of totality and the coach erupted into cheers and clapping; whatever happened now we were at least in the right position to see a total solar eclipse, whether or not the weather played ball, and the feeling of relief was immense.

We carried on north, ever closer to our observing site on the eclipse centerline. At times the route was practically empty (see the blurry pic from my phone below). And as dawn was breaking we could also see that there was only a small amount of scattered, broken cloud in the twilight sky. Things were looking good!

Around 6:20am we arrived at the parking area at the North Menan Butte and were joined shortly thereafter by the other Omega Holidays tour group led by Omega’s Peter Truman and The Sky at Night’s Pete Lawrence, who had travelled from their hotel in Idaho Falls. Some of the groups stayed with the buses at the base of the butte, while the rest of us began the mile-long hike to the summit some 220 metres above.

Looking back down towards the coaches from about 2/3rds of the way up the butte. A layer of morning haze and (possibly) wildfire smoke can be seen on the horizon.

From our chosen vantage point on the south side of the north butte we could see right out across the whole Snake River Plain and the South Menan Butte directly in front of us. The Tetons were also visible in the haze on the eastern horizon.

The view looking south from our observing site – the South Menan Butte is the large raised feature in the middle distance (at centre).

The local authorities had obviously planned carefully and extensively for the eclipse, as fire-fighting supplies were being dropped at the summit by helicopter as we arrived and there were a number of mounted police and other officials present. Large numbers of people — several hundred, at least — had assembled as the minutes ticked down to first contact and as the eclipse began there was a festival atmosphere with folks doing yoga exercises, playing guitars and singing (not all at once!) alongside the other eclipse watchers and astronomers with telescopes and cameras pointed skyward.

By the time of first contact the skies above were superbly clear with some moderate haze and wisps of distant light cloud low on the horizon. I had placed a large piece of flat, white, foamboard on the ground primarily to help us see the shadow bands either side of totality, but it also proved useful for displaying the strange shadow effects created by the partial phases of the eclipse — including shadows with both fuzzy and sharp edges — and projections of crescent Suns.

At left, my shadow bands ‘detector’ & (at right) my main imaging rig consisting of a certified solar filter, 66mm refractor, Canon 6D & Sky-Watcher Star Adventurer mount.

Shadow effects during the partial phases of the eclipse (some edges sharp, others fuzzy). Look carefully at the gaps between the shadow fingers – crescent Suns!

The two pictures below show the final stages of the first partial phase – captured using a specialist certified ‘white-light’ solar filter – with the Sun’s crescent just beginning to break up at the ends.

Just prior to totality I was delighted to finally, conclusively, see shadow bands jittering across the white board that I had laid on the ground. I thought I saw them during the 2006 eclipse in Turkey but couldn’t be absolutely sure as the surface around us was mottled marble, which made confirmation very difficult. Here, though, I could definitely see them, though they are undoubtedly a *very* low contrast phenomenon (at least from my perspective & observing site during this particular eclipse). Make sure to select the ‘1080p’ HD option in the video below for clearest playback.

Some time before second contact a stiff breeze had picked up at the summit of the butte and the crescent Sun was dancing erratically around the live-preview screen of my DSLR as the gusts wobbled the mount and telescope. As totality rapidly approached I thought my plans to take multi-second tracked shots of the extended corona and Earthshine had had it. Luckily however the oft-reported microclimate associated with the arrival of the umbral shadow seemed to save the day, as a few minutes or so before second contact – just as the sky went a silvery blue – the wind dropped completely.

The following pictures capture the eclipse from the beginning of second contact. These range from images of the first diamond ring and the appearance of the chromospheric arc to longer exposures showing the inner and outer corona and the Earthshine on the ‘new’ Moon. I was also able to capture a wide view of the eclipsed Sun showing a segment of the spectacular 360-degree sunset which surrounded us.

The corona itself was breathtaking and was dominated – in the naked eye view – by two, long, helmet streamers extending off the top right limb of the Sun and a third of a similar size on the opposing side. One thing I did observe was that, due to the clarity of the sky (above an altitude of a few degrees at least), – and in stark contrast to the 2015 Faroe Islands eclipse, where we had largely cloudy skies – it felt like the approach of the umbral shadow was much more difficult to discern. It was only in the very final minutes prior to second contact that its presence was *really* noticeable on the western horizon with the beginnings of the 360-degree sunset; perhaps this sensation was compounded also by the conspicuous layer of haze (and likely smoke too, given the numerous wildfires in the Pacific Northwest at the time), that hugged much of the western and southern horizon.

The diamond ring prior to second contact. A single bead of light is beginning to ‘break away’ on the southern end of the ‘diamond’.

The development of the second contact diamond ring and the appearance of the chromosphere.

The pinkish-red chromospheric arc just prior to the moment of second contact.

A wide view of totality – the star at bottom left is Regulus in Leo.

A rotated image of the eclipsed Sun during totality. The ‘polar plumes’ in the corona are visible as are the bases of the three main helmet streamers.

A short exposure image showing structures within the inner corona.

Background stars visible to the camera during totality with a (deliberately) overexposed corona and Earthshine visible.

Two prominences on the limb of the Sun during totality.

A wide view of totality with the 360-degree sunset.

A composite image combining a processed picture of the solar corona with a longer exposure showing Earthshine on the ‘new’ Moon.

The start of the third contact diamond ring (deliberately) overexposed to capture the wider coronal streamers and the diamond together.

The image below was created by Dr Karl Battams using professional data combined with one of my composite images of the inner corona and Earthshine on the Moon’s disc. In it you can see how the features in the inner corona seen by us on the ground connect with the fainter, more extensive, coronal structures visible from Sun-observing spacecraft – in this case SOHO – in space. You can read more about the image and what it shows on the NASA SOHO website here.

A composite image using one of my eclipse pictures (at centre) with data from the NASA/ESA SOHO satellite showing the outer corona – created by Karl Battams.

After the end of the eclipse we made our way back down the butte in the scorching afternoon heat and back onto the coach for the drive back to Pocatello. As the pictures below show, this was the first time we encountered the kind of traffic that had been predicted to materialise around the eclipse. While it took us just over an hour to get to the observing site, with the interstate crawling along slowly all the way home, it took nearly six hours to make the journey back.

Early the next morning the group gathered in the hotel’s conference room for a ‘debrief’ presentation where – with the help of some seriously strong coffee – I showed some rough-draft images from totality that I’d processed overnight; it was also a chance for everyone to share and discuss their own recollections and special memories from the eclipse before we set off for a day in Yellowstone National Park and our final destination on the trip, the town of Cody, Wyoming.

The Grand Canyon of Yellowstone

Roadside buffalo resting and grazing in Yellowstone National Park.

This trip was really made by the people who were on it and I’m immensely thankful for the camaraderie and friendliness of my fellow eclipse chasers on ‘Bus 4’. Special mention should also go to Mary, our tour director, and Robert, our driver, who through their professionalism and good humour made our adventure across hundreds of miles, around four states, a tremendously enjoyable one.

WARNING: observing the Sun can be extremely dangerous. Never stare at the Sun with the naked eye and never observe or photograph the Sun (or the partial phases of a solar eclipse) using an unfiltered telescope, camera lens, binoculars, camera viewfinder etc. Doing so risks serious damage to your eyes and/or equipment. The only safe way to observe the Sun is with a specialist, certified solar filter, following the instructions of the manufacturer precisely.