A Tale From Our Leader: PechaKucha
Once upon a new Moon the Sun finds itself slowly getting obscured, a shadow several hundred miles wide starts to darken the Earth in mid-day. An hour later, the darkness is total. The temperature drops by a few degrees. Nature becomes very quiet. Not a sound can be heard, not a bird sings. A feeling of suspense and awe, sometimes fear, electrifies the air. Those lucky to have reasonably clear skies in the direction of the Sun suddenly cheer, and yell, others are dumbfounded and scared, as they witness a cosmic spectacle beyond compare. The Sun’s beauty is suddenly revealed. A diamond ring glitters in the darkened sky. Red flames protrude beyond the edge of the Moon. Long ago someone named them prominence. The mystery of their pinkish color was solved when an invention called the spectrograph, revealed that it was none other than hydrogen, the element essential for life, but at a temperature of 10,000 degrees. A crown appears beyond these flames. It shimmers as it fills space, with streamers whishing outwards any which way. Cameras snap with hopes to capture the sight they behold. Alas, when the photos are produced the eye-witnessed beauty is subdued. We have solutions say Milos Druckmüller and Huw Morgan. They come up with different techniques to process the images to the level of what the eye can see. An even more beautiful corona is now revealed. Rays upon rays are everywhere, streaming, merging and diverging; curling in fiery beauty. They move across arches of all sizes, reaching out into the infinity of space. Every eclipse is a different magical surprise, revealing the intriguing beauty of coronal features revealed by the image processing. In the 2010 total solar eclipse, a clear wedge appeared to the west edge of the Sun, produced by the passage of a solar tornado. An elongated helical sheet to its east emerged from the snapping of a prominence. In 2012, the corona was littered with balloon-shaped bubbles. One bubble to the northeast seemed attached by a long tether. Streamers were distributed evenly around the Sun. Some ripples were seen here and there. This was at a time when the number of sunspots was at its highest within the approximately 11 year cycle of rise and decline. So, the Sun is changing, but we do not know why. Peer up at the Sun and you will see black spots. They reveal the presence of the mighty magnets created deep below its surface. As eclipses reveal, the corona changes in tandem with their number in an unpredictable way. Not only are bright rays and streamers ubiquitous in all eclipse images, so are faint bubbles revealed by image processing. Some of them are tiny, others huge, some of them like smoke rings. They expand outwards to the edge of the images. Where do they come from? Do they continue their voyage into space unscathed? Are these faint features a fluke of the image processing? Before photography, people drew what they saw. During the 1860 eclipse Tempel drew rays upon rays, with one bundle strangely twirled in a ball. By comparison, the processing reveals not only features similar to what Tempel had seen, but far more fainter details that are hidden to the eye. With special filters attached to the cameras, colors are revealed that no eye can see. In 1945 Edlen and Grotrian discovered that the red was Fe XI stripped of 10 of its 26 electrons, while green was Fe XIV that lost 13 electrons. Such a massive electron loss can only happen if the corona is at a million degrees or more, a mystery yet unsolved. With this high temperature, the corona is swept into space, by winds of 300 to 800 km/s. When comparing the relative brightness of Fe XI, with that of the white light structures, red patches of Fe XI show up in a few places, where these ions can be occasionally trapped in the corona unable to escape with the wind. More mysteries also emerged when we discovered that the relatively cool prominences were embedded in the hottest material in the corona. A close-up view reveals that prominences can stretch away from the solar surface as they become intricately intertwined with the filamentary structures of the corona. On the other hand, at a million degrees or more, the corona can emit x-rays and extreme ultraviolet radiation; this property provides new tools for observing the corona outside eclipses from space. One of the colors in this space image is from helium, discovered by Lockyer and Janssen during the eclipse of 1868. It reveals exquisite details of highly filamentary material in prominences. 2013 was the first time when two plasmoids were detected during an eclipse so far from the Sun. They seemed to be desperate to escape, while still tethered to the surface. This eclipse also revealed how their passage shook the corona, pushing streamers aside, with rays wriggling in response to this bullying approach. They are the counterparts of coronal mass ejections, faint huge bubbles discovered from space with manmade eclipses. They expand outwards at speeds sometimes reaching a few thousand km/s, producing shock waves in space. The solar wind and these CMEs sweep past the planets, as the Sun tries to catch up with the stars. What controls their speed remains a mystery. Through its wind’s voyage the Sun’s fickle magnets tease the Earth’s molten core to produce its own show. In the deep clear winters of the arctic nights, drapes of yellow, red and green rays suddenly adorn the sky. They reveal an eerie landscape of strange features and more, as they shimmer and swirl. Back to Tatakoto to 2010, the eclipse is over all too soon. The Sun starts to peak behind the Moon, its brightness blinding, its beauty gone. All that is left is a bright yellow ball with a few beauty spots, mind you. As if nothing happened, birds start to sing and dogs bark. But spectators are still in a daze. The evening after at dusk, a sliver from the new Moon smiles mischievously, proud to have put on a magnificent show. It lingers asking for attention and thankfulness. In the day after, all will be forgotten, but not for the Moon, who knows that it can repeat its trick, even if it has to wait a year or so. So, here we have descended upon this beautiful island beyond the arctic circle at more than 78 degrees north latitude. Some of us have traveled half way around the world, loaded with cameras, dodging the wrath of airport security. We have been preparing for a unique event with corona, aurora and polar bears. Let’s hope the Sun will not be shy, and will reveal the beauty of our own star and the wonders of the clockwork of planetary motion.
—Shadia Habbal, 2015
Total Solar Eclipses: A Sherpa’s Perspective
Our universe is filled with indescribable phenomena and total solar eclipses are no exception. The alignment of the Sun, Moon and Earth results in one of the most, if not the most, spectacular event anyone can witness. No words will suffice to describe the beauty and grandeur of these events. Before 2015, I had never experienced a total solar eclipse, but having always been fascinated by the universe and its tricks, I knew it would be a memorable experience.
In 2015, I joined the Solar Wind Sherpas, an international group of scientists and explorers led by Professor Shadia Habbal (IfA, Hawai’i) who travel the world to observe and collect data about the solar corona during total solar eclipses. Though I had already entered the field of Solar Physics in my research, it wasn’t until my first eclipse expedition that I learned the importance of total solar eclipse observations in our understanding of the Sun’s corona, or atmosphere. Beyond the solar surface, or photosphere, lies an atmosphere that manifests itself naturally only during a total solar eclipse. The name ‘corona’ is used to describe the bright halo that appears during totality. In science, we have come a long way in developing our current understanding of this atmosphere, its composition, what defines its ‘shape’ and what fuels its expansion. Armed with the notions of what a total solar eclipse is, how it occurs, and what science it can yield, I was ready to experience one. Or so I thought!
The 2015 total solar eclipse occurred over Svalbard, a Norwegian archipelago in the Arctic Circle. The expeditions carried out by the team are always intense, not just in terms of the equipment setup and testing, but because of the places (usually remote) we find ourselves in. Being in the Arctic presented the added challenge of dealing with extreme cold conditions and its effect on the equipment. In the days leading up to the eclipse, time has to be allowed for adjusting to a new environment, unpacking, setting up, testing equipment and dealing with any issues that arise. As time flies and the countdown to the eclipse begins, I realize how extraordinary the group is. They aren’t just scientists who carry out observations, they are people who are invested in an expedition, work long hours and join forces to achieve a common goal. They are a team.
Eclipse day arrives. Four years of preparation had gone by, months of building the equipment, weeks of testing, days of assembling and re-testing and an early morning of finalizing details. Despite how tired everyone is, we are all filled with anxiety and excitement. The instruments stand still almost in anticipation of the big event, personal cameras are fiddled with perhaps in an effort to release the anxiety and everyone is wearing warm clothes. It is 1 degree F (-17 Celsius) with a “feels like” temperature of -16 F (-26 Celsius). The Sun is beaming and a few wispy clouds make their way across it like uninvited guests. On the street, buses, snowmobiles and cars bring the spectators to their observation spot. Scientists, students, tourists, locals, artists and the media are all there, in this spectacular region of our planet, for the same reason. We were all there to observe a natural phenomenon belonging to our universe.
All of us stand in the cold, waiting for the moment of truth. Someone in the distance shouts, “First contact, first contact!” The Moon has reached the Sun, moving in front of it in a slow waltz. Spectators watch, take pictures, and do jumping jacks in an effort to keep warm while totality is reached, knowing that the temperature will drop a few more degrees. Finally, totality is reached. The Moon stands between us and our Sun not knowing, or perhaps knowing, what phenomenon she has created. Darkness comes. The Sun’s atmosphere reveals itself, shining over us. It quickly becomes clear why the Spanish astronomer, José Joaquín de Ferrer bestowed on it the name ‘corona’ all those decades ago. The prominences that are visible along the Sun’s limb, almost waving at those observing them, remind us of how active our star is. A silence follows a quick cheer from the crowd. No words can describe the feeling one gets when witnessing such an event. The entire world around us has disappeared. It is just us and the eclipse. How lucky we are! Slowly, as the Moon starts to eclipse our star, I start to realize how small we truly are and how small we truly feel. I realize how wonderful life is and how fortunate we all are to be in this very spot as scientists but beyond that, as people who have come together to make this an unforgettable week.
The Moon continues to waltz her way across the sky. The Sun slowly appears behind the Moon. Light ensues once again, final pictures and videos are taken, a few more cheers can be heard and lots of smiles can be seen. We enter the observatory and embrace and congratulate each other. Those two minutes of eclipse time brought us all here and connected us. We head back outside to talk to the media as champagne is passed around. The Moon has left the stage and the Sun proudly shines knowing we are all talking about him. As people clear the area, we are left alone in the observatory once again. We know we had perfect conditions, but we look forward to sorting through our data!
The day after an eclipse is difficult to describe. There is a sense of accomplishment and fulfillment that is quickly ensued by a hint of sadness and emptiness. From a scientific standpoint, having experienced a total solar eclipse under perfect sky conditions trivializes the stress and frustration that governed the days and weeks leading up to the eclipse. From a personal standpoint, witnessing such a beautiful event is a humbling experience during which we find our place in the universe. In the darkness of an eclipse, when all is quiet, it’s as if the world stands still and we are nothing more than an insignificant creature in this one corner of the universe. As the Sun is revealed once again, we are elevated to a higher stature. We are now a critical piece of the puzzle that is the universe. We belong to it and we are connected to it.
Not all expeditions are successful. After all, we are dependent on clear skies in order to carry out our observations. In 2016, the total solar eclipse was seen over Indonesia. This was my second expedition. We split into three groups and each observed from a different location in Halmahera: Maba, Buli and Plun Island. I was on Plun Island, a tiny uninhabited island. A staff from Maba was there during the week to help us out. We provided them with eclipsing glasses so they could enjoy the show from the beginning until totality.
On eclipse day, the time of first contact arrives. The Sun is hidden behind thick clouds. Only for a minute or two at a time are we able to see enough of the Sun to use our eclipsing glasses. It is a waiting game, best put by a fellow Sherpa who compares the eclipse to a lottery. We purchased a very expensive lottery ticket and we must wait to see if we have the “winning numbers.” First contact at 8:37 am (local time) means the curtain is lifted and the Moon has begun its way across the stage. During moments of less cloud density, we put on our eclipsing glasses and watch the crescent that begins to form. A beautiful spectacle so amazing that no cloud coverage can take it away. One of the staff members, Nurul, had a reaction, which was absolutely inspiring. Her breath was taken away when she first saw the crescent forming. She was shaking with excitement. What a beautiful moment to witness! As scientists, we look for the clear skies and the perfect picture and data. We sometimes forget that we are looking at nature at its best. Three celestial objects have lined up to give us this beautiful picture. Nurul reminded me of that. What an honor to share this experience with her and the others. When the Moon takes center stage and totality is reached, pink/red prominences appear. There is much cloud coverage so we are only able to observe the low corona. The clouds have deprived us of the extended corona. During totality, you could hear the excitement from the people around us. For most, it was their first time seeing an eclipse and they truly enjoyed it. It was a very moving experience being there, getting to know them and sharing our adventure with them.
We are now preparing for the 2017 total solar eclipse over the continental USA. With 5 observing sites planned, the Solar Wind Sherpas hope to maximize the chances of obtaining good data. Bring on the show!
—Naty Alzate, 2017
It Never Gets Old
No matter how many eclipses I see, I am still astonished that we can predict when and where to stand to look up and see the Moon cover the Sun. It will never get old!
Reflections on Indonesia
We have all been touched by the diversity of cultures in Indonesia and the peaceful coexistence of people from different ethnic and religious backgrounds. It should be a model for the world! Every place we have been to, people have been extremely generous and welcoming making us feel at home despite the language barriers.
—Solar Wind Sherpas on the 2016 TSE in Indonesia
Deep in the Zambian Bush
My favorite incident was when the wheel of our trailer broke off deep in the Zambian bush near Kafue National Park and bounced past us on the road. We managed to get to a destination (Hippo Lodge) where we spent the night. The next day, our guide unloaded and retrieved the broken trailer. We had to pull an old boat trailer out of the Kafue river, cut off the axel, and replace the broken one on the trailer. But it got us home! I still have a t-shirt with a bouncing tire on it as a souvenir.
—Rob Havasy on the 2001 TSE in Zambia
The Perfect Eclipse
The eclipse was a miracle because the morning was absolutely excellent. Finally, the data we have is over our wildest dreams. I am extremely happy!
—Milos Druckmüller on the 2015 TSE in Svalbard