On Aug. 21, 2017, the entire continental U.S. will see a solar eclipse. Only a 70-mile wide stripe across the central part of the country will experience totality. Image Credit: NASA
Eclipses have been a part of the history of every culture since the beginning of humanity. Ancient societies as far back as 1375 B.C. have recorded total solar eclipses. Most believed that eclipses, both solar and lunar, were portents of events to come. The majority saw eclipses as fearful events – things that went against the laws of nature and their gods.
The alignment of celestial bodies is an astronomical event called syzygy. This can create an eclipse, occultation, or transit. As much as the average citizen looks forward to the wonder and beauty of an eclipse, scientists around the world use syzygy to do some remarkable science.
Some of the most pivotal discoveries in modern memory have been due to syzygy. These include Sir Arthur Eddington’s proof of Einstein’s Theory of Relativity by the observation of the Sun’s gravity bending the spacetime around it to reveal the light of a star hidden behind the Sun during an eclipse, and the discovery of thousands of extra-solar planets (exoplanets) by the Kepler Space Telescope using the transit method or even by ground-based telescopes using microlensing.
For instance, the scientists behind the New Horizons mission that visited Pluto in 2015 have recently used stellar occultation to gather more information on the small Kuiper belt object known as 2014 MU69 prior to the spacecraft’s flyby of it coming up in January 2019.
Astronomers and other scientists use these events to gather information that can’t be gathered in any other way. Total solar eclipses provide an opportunity to view a part of the Sun we cannot properly see any other way – the corona.
The corona is the outermost layer of the Sun and is equivalent to its atmosphere. It is one of the most mysterious aspects of our closest star. NASA recently renamed Parker Solar Probe will be launched next year to study this mysterious part of the Sun.
Unlike every other place we are aware of, the farther you get from the center of a planet or other celestial body, the cooler the temperatures get. That’s not how it is with the corona of the Sun. In fact, the corona of the Sun is millions of degrees hotter than the surface of the Sun.
Capturing the moment
For many astrophotographers, capturing a total solar eclipse is one of their bucket list items. It’s not a simple photograph to be able to capture for myriad reasons, the smallest of which is trying to be in the right place at just the right time. Even if you find the right spot along the line of totality, there’s no guarantee the weather will cooperate. Additionally, totality will only last for a maximum of 2 minutes, 40 seconds, depending on where you are. Click here for a list of totality times.
As many eclipse chasers can attest, you can spend large sums of money traveling to remote locales only to find that clouds block the view. Because the surface of the Earth is covered primarily in oceans, the likelihood of an eclipse happening on inhabited land is pretty low, which is what makes the August 21 eclipse a truly special event.
This eclipse has been billed by some as the “Great American Eclipse” since the entire path of totality occurs only touches land within the borders of the United States and has the potential to be the most-viewed eclipse ever.
Massive numbers of people from all over the planet are making the trek to locations along the path of totality in order to see this celestial event. Most of the areas where the eclipse will be viewable in totality happen to be relatively small towns and rural areas, some of which are expecting massive influxes of people.
Madras, Oregon, for example, normally has a population of approximately 6,000 people. That is expected to swell to over 100,000 for the days before and on the day of the eclipse. This poses a list of potential infrastructure problems including gas shortages, nightmare-level traffic jams, and price gouging on anything and everything.
Even so, people seem happy and excited to have even a chance to see the eclipse. Liam Kennedy, owner and inventor of ISS-Above, drove two days from Southern California to central Oregon to view the eclipse and is looking forward to “being enveloped in the Moon’s shadow”.
“I mean, literally, there will be a shadow on me from the Moon,” Kennedy said. “There will be a direct connection between me, and the Moon and the Sun! I mean, wow!”
This excitement and interest span a wide range of ages and genders. From school-age children to long-retired people who have never had the opportunity to see an eclipse before, the fevered interest is palpable.
Astrophotography hobbyist and amateur astronomer Chris Hetlage plans to stay mobile and try to outsmart Mother Nature. Hetlage, who began taking photographs in the late 1980s, has out run weather in order to get stunning images of lunar eclipses and even the transit of Venus. After capturing an annular eclipse in Chico, California, in 2012, he knew he wanted to photograph a total eclipse.
Hetlage plans to be well armed with a plethora of equipment in order to maximize the possibility of imaging the eclipse somewhere between Saint Louis and Kansas City in Missouri, and he will go as far as Nebraska or Montana depending on how the weather looks leading up to the eclipse.
The crew of the International Space Station witnessed the shadow of the Moon racing across Earth during the March 29, 2006, total solar eclipse. Photo Credit: NASA
Citizen science opportunities
Once the eclipse starts, if you’re not in the path, it’s virtually impossible to chase it. The shadow of the Moon moves at speeds upward of 2,288 mph (3,683 km/h), which is greater than the speed of sound. People have stood on mountain tops and watched the Moon’s shadow race across hundreds of miles to find them in just a matter of minutes.
For those who aren’t familiar with the affects of a solar eclipse, the changes in temperature, development of clouds, shifts in winds, and even animal activity can be startling. For those who aren’t in the path of totality, there can still be significant impacts.
NASA sponsors an application called the Globe Observer that they hope will appeal to citizen scientists. The application gathers data about weather, temperature, with other projects about animal behavior, coronal imaging, and ionosphere activity from across a wide range of areas where both totality and partial eclipse will be able to be seen. The data is then correlated by scientists in an attempt to better understand the impacts of the Sun on the weather here on Earth.
Those interested in conducting eclipse related citizen science can download the Globe Observer application as well as the many other ways to personally participate in citizen science projects.
For those who aren’t among the millions of people expected to be within the path of totality, or are but the weather in your area isn’t cooperating, NASA TV will be live-streaming the event from special high-elevation balloons, ground-based telescopes using various types of light and polarization filters, and even from specially outfitted jets.
Partial eclipse viewing safety
Even if one isn’t in the path of totality but will be within the continental U.S., the whole continent will still be able to see a partial solar eclipse. The most crucial aspect to viewing this phase is taking precautions for viewing safety.
Just like when the skin gets a sunburn, it’s not an immediate discomfort. When the inside of the eye receives a sunburn from exposure to the damaging rays of the Sun, it’s especially problematic because the inside of the eye doesn’t possess pain receptors. This means that the damage can go unnoticed until the delicate tissues of the retina become swollen and inflamed reducing vision. This can reverse over time, but in some cases vision can be permanently lost.
Only view the eclipse with approved eclipse safety glasses or viewers, or, better yet, make a pinhole projector to indirectly observe the eclipse. Indirect observation guarantees you won’t damage your vision. Pinhole projectors are easy to create and very inexpensive, taking from five to 10 minutes for the pinhole projector.
If you’re unable to make it to the path of totality or are unable to fully appreciate it from your location, you can start planning now for the next total solar eclipse that will be in the United States on April 8, 2024.
Video courtesy of NASA
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