Total Eclipse 101 with Dr. Martina Arndt
News & Events
On Aug. 21, the United States will experience a total solar eclipse, darkening skies from Oregon to South Carolina. To mark the event, the Center for the Advancement of STEM Education will host a viewing of the solar eclipse that day from 1 to 4 p.m. Special glasses to view the eclipse will be available (while they last), four solar telescopes will be available, and a talk on eclipses by Joseph Doyle will be held from 1 - 2 p.m. in the DMF auditorium. The event is free and open to the public.
Dr. Martina Arndt of the physics department will be leading a team of researchers who will be spread across the United States observing and collecting data connected to the upcoming eclipse. Other BSU facutly members participating are Niki Glen, Maria Hegbloom, Mercedes Nunez, Veronica Cote, and student Maria Patrone.
To help you prepare for the total eclipse, we asked Professor Arndt to share some thoughts about the upcoming event. In the video below, she provides a quick overview about the upcoming event. Below that is an interview with Dr. Arndt about the eclipse, her years of research into these events, and what it’s like to be a woman in her field.
Q: What will you be doing during the solar eclipse? And when exactly is it expected to occur?
A: I will be leading a research team in Alliance, Neb., and in that location, totality (when the moon totally covers the sun) will happen for two and a half minutes starting at 11:50 a.m. local time.
Q: How is a solar eclipse defined in scientific terms?
A: A total solar eclipse is when the moon’s umbral shadow passes across the earth’s surface; this can only occur when the moon is aligned between the sun and the earth. The path of the umbral shadow is called the ‘path of totality.’ During totality, the sun’s corona (upper atmosphere) is visible.
Q: This is going to sound like an odd question, but why do we study solar eclipses?
A: The sun’s corona is 1000 times dimmer than the sun’s surface. During a total solar eclipse, the moon blocks out the sun’s surface and we can finally see the corona. The corona is an interesting place – it is 500 times hotter than the surface of the sun, and that is not what we expect (it would be like moving away from a heater and getting warmer!). During an eclipse, we gather data to better understand this ‘coronal heating problem.’
Q: What will the duration of the solar eclipse?
A: It takes about three hours for the moon to cover the sun and then uncover it; most of that time the sun is only partially eclipsed. This year, if we could travel 1,700 miles per hour as the moon’s shadow traverses the continental U.S., we could observe a total eclipse for 90 minutes. However, standing in one spot, observers will only able to see totality for up to 2 minutes 40 seconds (depending on location) as the moon’s shadow passes over them.
Q: How often do solar eclipses typically occur? Also, when was the last one? And when is it expected to happen again?
A: The moon is between the sun and the earth once a month, however the moon’s shadow does not always pass over the earth’s surface – it is usually above or below us. About twice a year, the moon’s shadow does cross the earth, but because the moon is sometimes further away from us (and therefore appears smaller), it doesn’t cover the entire sun, so we do not see the corona. As a result, conditions for total solar eclipses happen, on average, once a year. The last solar eclipse visible from the continental US was on Feb. 26, 1979, when parts of the northwest were in the path of totality. After this year, the next eclipse visible from the continental U.S. will be on April 8, 2024 – where totality will pass through Vermont.
Q: How did the opportunity to go to Nebraska for the eclipse come about?
A: I became involved with observing solar eclipses through of my colleagues, Dr. Shadia Rifai Habbal, who is the head researcher on the project. To maximize our data collection during this year’s eclipse, we will have five teams situated along the path of totality – and one of them is in Alliance, Nebraska. Dr. Habbal asked me to lead this team in part because I have been part of 10 eclipse expeditions already.
Q: What do you hope to achieve with your study this summer?
A: We plan to collect white light data to observe the corona’s magnetic and density structure during the eclipse, as well as spectra to learn more about coronal motion and composition, and light from ionized iron to determine its density which helps provide clues about coronal hearing.
Q: Is it safe to look at with the naked eye or can you cause damage?
A: It is safe to look at a total solar eclipse, but never during any of the partial phases.
Q: Are there any known superstitions or cultural significance tied to solar eclipses of which you’re aware?
A: Native Americans consider eclipses to be sacred events, and many avert their eyes. Solar eclipses have inspired myths in many cultures, particularly before we understood the mechanics of eclipses – imagine how frightening it must have been to see the sun disappear and not know why!
Q: What types of studies/researches have you done on solar eclipse events in the past?
A: Dr. Habbal’s research focus is on the infrared light emitted by the corona. Through this work, we can explore the conditions under which different processes take place and how they contribute to coronal heating – and to the solar wind (a steady stream of charged particles leaving the sun.)
Q: Is the solar eclipse something that people can photograph with their phones?
A: During totality, yes. But the images will not be spectacular. There is an effort afoot to combine people’s personal total eclipse images into an Eclipse Megamovie (eclipsemega.movie/) but that applies to people in the path of totality. During the partial phases (like what will be visible in New England), you can take cell phone pictures but with a filter. If you are near BSU on August 21, come take part in eclipse related events at the Math & Science Center.
Q: How does the ability to go out and research help you in the classroom as a professor?
A: As an educator, in addition to helping students learn, I love to share my own experiences. Studying eclipses, taking part in data collection, and using different equipment challenges me and keeps me current. I am fortunate that my work can be used as an example of how to do science and what it is like to be a scientist – I get to share the excitement of working on a diverse team, of traveling the world, and the trials and tribulations of actually doing science.
Q: Can you tell me about your role as a female physicist?
A: Thirteen percent of physics PhDs (the typical degree for someone doing work like this) were awarded to women when I graduated - and the number is closer to twenty percent now. When Dr. Habbal earned her degree in 1977, she was among the five percent of women who earned PhD’s in physics. The numbers have increased over time in part due to efforts by people like Dr. Habbal who is deliberate and passionate about supporting female scientists – and I try to do the same. I can definitively say that I would not be where I am now without her. It is absolutely significant to have women leading research teams like ours – our goal is to reach a point where it is not a notable event that we do.
Q: Why did you decide to make your career about doing this? What is it about studying solar eclipses – and by extension, astrophysics – that you love so much?
A: When I was a kid, I was fascinated by space – and I owe a lot of that to Carl Sagan and (the television show) Cosmos. I also loved photography – and when I got to college, I majored in astronomy not just because of space, but because I could tap into my creative side through imaging. Dr. Habbal hired me after college to be her solar physics research assistant, and that is when I fell in love with the sun; it is dynamic and beautiful, and it is a star – a huge ball of plasma - right in our back yard! So, when Dr. Habbal started studying eclipses, I was thrilled when she included me as part of the team. My first eclipse was in 1997, and I continue to be amazed that scientists can predict when and where to stand so that when we look up, the moon covers the sun perfectly. It is an amazing experience to be able to see the sun’s corona, even if only for a few minutes, and it is incredibly satisfying to collect such valuable data. (Interview by Charlie Peters, University News & Media; Video by Moakley TV Studio)