The recent August 2017 total solar eclipse awed millions across America as they witnessed an astonishing astronomical phenomenon, most of them for the very first time. It was described as ‘beautiful’, ‘breathtaking’, and ‘mystical’. Some even saw it as a spiritual experience. The eclipse also provided a wonderful opportunity to make an interesting proposal for citizen science. Researchers started the Eclipse Megamovie Project in an attempt to create a comprehensive 90-minute ‘movie’ of the eclipse’s line of totality, which is the path of the Moon’s shadow over the Earth, across the United States. Both amateur and experienced photographers were recruited to capture photos during the solar eclipse and upload them to the Megamovie site. The final result? More than 50,000 photos from DSLR cameras were submitted by over 1,100 volunteers! Now, Megamovie researchers are working on compiling that data and making sense out of all of it. The collection of this massive data set presents an amazing opportunity to learn more about the science of the Sun.
The Megamovie project has relied on the combined efforts of volunteer citizen scientists, trained photographers, and professional researchers. Its popularity and success has depended on the partnership of science, outreach, and technology. The leading researchers on this project came from UC Berkeley’s Multiverse Team and from Google’s Making & Science team. Other groups contributing to the project include the Astronomical Society of the Pacific, Lick Observatory, Oregon State University, and Sonoma State University. Photographers who contributed images to the project are directly credited at the end of the mini-Megamovie that is linked near the bottom of this post.
The efforts to contribute to Megamovie have come from people all across the nation. The photos that will be used for the Eclipse Megamovie project are those that were taken along the line of totality. The August 2017 path stretched all the way from Corvallis, OR to Charleston, SC for a total distance of approximately 3,000 miles. The path covered a width of 70 miles in the longitudinal direction as it crossed the US. The map below shows the path of the eclipse with the darkened line in the middle representing the path of totality.
The eclipse documented by the Eclipse Megamovie Project occurred on August 21, 2017. Its total trip across America lasted 90 minutes, starting at around 17:16 UTC and ending around 18:46 UTC. At this point in time, a full Megamovie is not available. There is not yet a set date for its release. Researchers hope to repeat their experiment for the solar eclipse that will pass across North America on April 8, 2024.
In order to understand the why? behind the Eclipse Megamovie Project, some important solar concepts must first be established.
Everybody knows that the Sun is a star. But what else should they know about it? It is 150 million kilometers away (eight light minutes) – that’s 93 million miles – from Earth and almost five billion years old. Its age puts it in its main sequence stage, which means that the Sun is a “middle aged” star. The Sun’s power output is approximately 3.8 x 1033 ergs/second (or 5 x 1023 horsepower) and its energy output is approximately 3.8 x 1026 Joules (Watts) per second. Its core reaches temperatures of 150 million °C. Its diameter measures 1,391,000 kilometers (864,000 miles). The Sun is enormous compared to the other bodies in our solar system, taking up 99.64% of the solar system’s mass. 1.3 million Earths could fit inside the Sun. Most of the Sun’s mass is made up of Hydrogen, around 70%, and Helium, around 28%. The rest is mostly Neon, Iron, Silicon, and Magnesium. The Sun is at the heart of all biological processes on Earth. Our lives are intimately connected to that star at the center of our solar system.
A total solar eclipse is when, from someone’s perspective on Earth, the moon totally covers the Sun. This happens due to a strange and cosmic coincidence: the moon is 400 times smaller than the Sun, but the Sun is 400 times farther away from Earth. The eclipse’s path, the area of the Earth covered by the moon’s shadow, is composed of two parts: the umbra, the path of totality, and the penumbra, the path of partiality. Total solar eclipses happen about every 18 months but their line of totality is not always visible across a long path of accessible land. The August 2017 eclipse was particularly important because it spanned across such a large portion of the United States.
There are a few different phases of an eclipse that can be identified. The Diamond ring effect is an event in which a large, bright flash of light occurs right before or after (typically 15-20 seconds) the moment of totality. Baily’s Beads occur 5 seconds before or after totality at the instance when the Sun is 99% obscured and a small jewel bead of light is left. Totality is exactly what it sounds like. During the moment of totality the Sun is totally obscured by the Moon and the corona (described below) becomes visible. Totality, during the 2017 eclipse, lasted for a maximum of two minutes and forty seconds.
The three most important layers of the Sun to know for Megamovie are the photosphere, the chromosphere and the corona. The photosphere is the immediate outer layer of the Sun. Its light is the sunlight we have here on Earth. The chromosphere is a thin, crimson layer resting between the photosphere and the corona. The corona is the very last layer of the Sun. It is also made of plasma and extends many solar radii out from the Sun. These three layers are where many notable solar events occur such as sunspots, coronal mass ejections and solar flares. The Sun follows a rhythm of solar maximums, when solar activity is the highest, and solar minimums, when there is relatively low solar activity. Charting of this pattern has shown that the number of sunspots & solar storms rhythmically rise and fall every 11 years. The shape of the corona also changes as the Sun rotates through this cycle. It has been theorized that the nature of the Sun’s spin may contribute to many of its odd characteristics; while it rotates fully in 27 days, its rotation is 25 days at the equator and 36 days at the poles.
In typical daylight, the only part of the Sun that can be viewed is its photosphere. Its outer atmosphere, composed of the thin chromosphere and the corona, is concealed by the bright light of the photosphere. Scientists can view part of the corona from above most of the atmosphere using a device called a coronagraph. However, an eclipse provides them with a more detailed (and beautiful) view. There are many mysteries in the Sun’s outer atmosphere. For one thing, it is much, much hotter than the Sun’s photosphere and, at this point, scientists do not know exactly why. Solar prominences, coronal mass ejections and solar flares are additional atmospheric occurrences Megamovie researchers have been looking into. In August, they were pleased to find that instruments had picked up on a CME that occurred during the solar eclipse at around 17:15 UTC. Examining the photos from that time period could provide a brighter insight into the solar events during and after a coronal mass ejection.
The Importance of Discovery
To confine our attention to terrestrial matters would be to limit the human spirit.
As humans, we have a natural desire to understand the world around us. Science gives us the tools to do so. The benefit of research may not always be initially obvious. This does not make it pointless. It is, after all, in our best interest to understand the Sun. It’s what keeps us alive. The Sun fuels our day to day lives. It will likely become even more important as we begin to look for renewable resources and as climate change begins to affect our environment. Discovery is essential to our growth as a society. We must always strive to understand the world to the best of our abilities or, otherwise, we will remain in darkness.
Problems Along the Way
Of course, the Megamovie project has not moved along without encountering problems along the way. There are, after all, more than 50,000 photos to be sorted! There is enormous variety between the photos: each one comes with different formatting, positioning, and style. The process requires finding an efficient and scientifically accurate way to calibrate the images, which has proven to be a very difficult task. The scattering of light particles as they enter the atmosphere also affects the accuracy of Megamovie results. Megamovie researchers are continually working on resolving these issues in order to preserve both the accuracy and preciseness of the experiment.
A lot of subsequent problem solving has involved developing new codes that can automate the process of photo analysis. The bright star Regulus, present in many of the photos, is being used as a reference point to determine the brightness and position of the eclipse within a photo. Megamovie Maestros was set up on Zooniverse in the hopes that the process might be sped up through the use of crowdsourcing. Unfortunately, these solutions give rise to newer and sometimes more difficult problems. A powerful computer is necessary to handle massive data input and subsequent output after being run through a calibration program. Image data types often have to be converted in order to work in particular programs. The fact that there has been so many complications in creating the Megamovie does not diminish the hopes of those working on it. In any successful research project, challenges are to be expected, but they are always overcome.
All important data and code used in this project has been made available to the public. As a plan built on the efforts of citizen scientists, Megamovie continues to benefit from the efforts of volunteers who choose to contribute their time to science. There are many ways people who want to help out can do so. The Zooniverse data set is in need of many more volunteers to refine photographs. Interested parties may use and, if they would like to, improve upon code and files posted on GitHub. Constructive feedback is appreciated. Megamovie is incredibly thankful for everyone who has volunteered their time and effort into this project.
“In 2011, an ‘Eclipse Megamovie’ was envisioned for the 2017 total solar eclipse that would be created using the public’s photographs of the Sun’s corona as frames in a movie illuminating dynamic changes in the chromosphere and corona. On August 21st, 2017 during and shortly after the total solar eclipse, our team collected photographs from thousands of volunteers with telescopes, DSLR cameras, and mobile device cameras setup across the path of totality. Our efforts resulted in 1,190 photographers contributing 50,016 DSLR photographs in a final open-source, public archive that is 766 GB in size. All photographs in this archive are creative commons zero, CC0, making them freely available for public use.”
– Excerpt from Abstract of paper being developed on Megamovie
Dr. Laura Peticolas and several other Megamovie researchers are currently working a paper to outline the process and results of the Megamovie project so far. This paper will include a summary of both the successes and challenges of Megamovie in its current form. It will also examine some of the tools that were used or developed by researchers. It will be especially useful for people interested in understanding the more technical, systematic aspects of this work. The paper will discuss methodology, necessary future improvements, data analysis, and the possibility of study replication. A large portion of the paper will explain the Megamovie team’s outreach efforts such as the Megamovie smart phone app, a documentary film series and various social media platforms. The paper will also go into greater detail on methods of data processing that will be used to complete the final movie. A detailed description of errors in this first Megamovie experiment and an explanation of the open-source nature of this project provide inspiration for readers to take up a similar endeavor for future eclipses. The development of this paper will hopefully lay the groundwork for other researchers to contribute to this scientific process. It is expected to be released by August 21, 2018 and will be referenced under ‘Resources’ once it has been made publicly available.
Sonoma State University’s SHIP, Summer High School Internship Program, was started with a partnership between the School of Science and Technology (SST) and the Sonoma County Office of Education (SCOE) in 2008. It was designed to inspire local student interest in STEM industries by offering a unique research opportunity to fifteen juniors in the area. Sonoma County high school students apply to the program for the summer after their junior year. Those that are accepted are awarded $1,000 stipends and the chance to participate in hands-on research with Sonoma State faculty.
This year (the summer of 2018), SHIP included a project for the Eclipse Megamovie. The student accepted into this internship would get the opportunity to work with Dr. Laura Peticolas of SSU’s E/PO group in conjunction with the UC Berkeley Megamovie team, particularly Dr. Juan Carlos Martínez-Oliveros. The selected intern would be able to access the public database of photos to contribute to the process of image organization, regulation and processing in a university setting. The student’s statement on the impact the SHIP internship had on her is below.
“As an intern on the Eclipse Megamovie, I was introduced to ideas and methods from astronomy that were completely new to me. I had to learn many new things: how to use Python, what FITS files are, the basics of astrophotography and so much more. Working on the Megamovie project has helped me gain a clearer image of what science truly means, on both a global and a personal level. Although it was challenging at times, I loved getting this one-of-a-kind research experience.
I didn’t see the August eclipse in person. I was in class and, from there, it was too cloudy to even see the partial eclipse passing over Sebastopol. During my time here, I got a second chance to experience the eclipse, but in a totally different way than I had once expected. Next time there’s an eclipse in the US, in 2024, I won’t miss it. I’m really looking forward to seeing the contributions Megamovie will make to science.”
– 2018 SHIP Megamovie Intern