Solar eclipses can only happen during the new phase of the Moon, when the Moon lines up between the Earth and the Sun. If the three bodies are not quite aligned correctly, then the Moon may block part of the Sun in what is called a partial solar eclipse; if the three are perfectly aligned, then the Moon can completely cover the Sun, creating a total solar eclipse.
That is, if you're lucky enough to be observing the total solar eclipse in Madras, OR. According to charts for the 2017 eclipse, Madras is expected to experience a period of totality clocking in at 2 minutes and 2 seconds.
Those with space-enthusiast parents may recall childhood days watching partial solar eclipses move across cardboard cut-outs or through solar filters. We use these devices to protect our eyes' retinas from infrared radiation, UV light, and excessive blue light.
Unlike their partial counterparts, total solar eclipses are actually safe to watch directly, even through binoculars. This time period of safe viewing is short, though — eye safety precautions must be taken in periods leading up to, and immediately after, the total solar eclipse.
The prospect of being enveloped in nighttime darkness during the day may seem spooky or fascinating, depending on who you ask. What you should know, though, is that while some parts of the United States will reach total darkness, many more will still experience partial light.
That's because the solar eclipse follows a path over the United States, crossing the country in a 73-mile-wide diagonal band. While that arch covers the entire United States, only the areas sitting directly beneath this path will experience total darkness. This is called the Path of Totality.
While a total solar eclipse is rare, solar eclipses in general are actually quite common. The Earth, moon, and sun align twice a year, leading to annular or partial solar eclipses.
Annular solar eclipses occur when the Moon blocks almost all of the Sun, but there's still a ring of light present around the rim. Partial solar eclipses occur when the Moon is only partially blocking the Sun, creating a small notch of darkness over the fiery orb. Americans not on the direct solar eclipse path in 2017 will see a partial eclipse — while it won't leave you in pitch blackness, it's still an incredible sight to behold.
The majority of areas on this year's solar eclipse path are not major cities. Most of the prime viewing locations are small American towns, such as Madras, Oregon. So, for those expecting to set out their lawn chairs in a big city or suburb, you may want to consider a road trip out of town instead.
The one exception is Nashville. Nashville is the only major city along the total solar eclipse route.
Other than Nashville, other capital cities that will have a good partial view are Portland, Oregon (99 percent totality), Atlanta (97 percent totality), and Seattle (92 percent totality).
Total solar eclipses do happen every few years. However, the audience witnessing these phenomena varies dramatically based on the date and the rotation of the Earth. For example, in 2016, parts of Southeast Asia experienced a total solar eclipse, and in 2019, South Americans will bear witness to one.
Eleven of the U.S. states are lucky enough to sit directly in the path of the 2017 event. But after this one, continental North America won't experience a total solar eclipse until 2024 — so make sure you're prepared on August 21, 2017.
