As most Americans probably know, the continental United States witnessed a solar eclipse last Monday. Not only are solar eclipses awe-inspiring and amazing to see by everyone, but they are also significant to science. Total solar eclipses allow the corona and chromosphere, the two outermost layers of the sun’s atmosphere, to be viewed. The corona looks like a white halo around the sun.
Normally, only the photosphere can be observed, which is the sun’s yellow surface. Because this light is much more intense than that of the atmosphere, it makes the outer layers very difficult to observe under normal conditions. The chromosphere is a thin layer of atmosphere that is just below the corona and above the photosphere. It looks like a crimson ring around the sun’s border and is viewable during eclipses and with sophisticated telescopes. During a solar eclipse, the moon blocks out the light of the photosphere, which makes the dim atmosphere visible.
Although scientists use certain technology to try and replicate the effects of eclipses, there are still parts of the sun’s atmosphere that can only be seen during true eclipses.
Unfortunately, the locations from which a total solar eclipse can be observed are limited. Some locations can see a partial solar eclipse, but many cannot see anything at all. Last Monday’s eclipse was visible in totality for many American cities, but most of them only got to see a partial solar eclipse. While partial eclipses are also fascinating, they do not provide the same experience of being able to look at the Sun while it is completely covered by the Moon, meanwhile everything around you is dark. Because of this, there are people who travel around to view solar eclipses in totality, and this is often necessary to get the best view.
Scientists also place eclipse observing equipment in the locations to get the best data, so it is important for them to know what the path of totality will be. The next upcoming eclipse is in 2019. Its path of totality will pass mainly over the Pacific Ocean but will also be visible to some parts of South America. At the end of 2019, a solar eclipse will be visible from parts of Saudi Arabia, India, and some Pacific islands.
A 2020 eclipse will make its way across Africa and Asia and will be visible from many cities in China. A 2023 eclipse will be visible from the western and southern United States along with parts of Central and South America. The 2024 eclipse will start in the south of the United States and travel northeast, giving many northeastern cities a great view of the eclipse. Even if you missed this one, there will be other opportunities to witness solar eclipses. If you’re lucky you may even be in the path of totality and get to watch as the moon appears to erase the Sun from existence.