What is Solar Eclipse ?

1. First contact is in Oregon. If you want to be the first person to experience totality in the continental U.S., be on the waterfront at Government Point, Oregon, at 10:15:56.5 a.m. PDT. There, the total phase lasts 1 minute, 58.5 seconds.

. Totality lasts a maximum of 2 minutes and 40.2 seconds. That’s it. To experience that length, you’ll need to be slightly south of Carbondale, Illinois, in Giant City State Park. You might think about getting there early.

The end of the eclipse for the U.S. is not on land. The center line’s last contact with the U.S. occurs at the Atlantic Ocean’s edge just southeast of Key Bay, South Carolina. I’m pretty sure the crowd won’t be huge there.

The end of the eclipse for the U.S. is not on land. The center line’s last contact with the U.S. occurs at the Atlantic Ocean’s edge just southeast of Key Bay, South Carolina. I’m pretty sure the crowd won’t be huge there.

Cool things are afoot before and after totality. Although the big payoff is the exact lineup of the Sun, the Moon, and your location, keep your eyes open during the partial phases that lead up to and follow it. As you view the beginning through a safe solar filter, the universe will set your mind at ease when you see the Moon take the first notch out of the Sun’s disk. Around the three-quarters mark, you’ll start to notice that shadows are getting sharper.

This eclipse will be the most-viewed ever. I base this proclamation on four factors: 1) the attention it will get from the media; 2) the superb coverage of the highway system in our country; 3) the typical weather on that date; and 4) the vast number of people who will have access to it from nearby large cities.

Only one large city has a great view. Congratulations if you’re one of the 609,000 people lucky enough to live in Nashville. The city center and parts north of it will experience 2+ minutes of totality. Unfortunately, that’s the only large city with a great view. In the tally below, column 1 lists 25 other large metropolitan areas. The second column shows the amount of the Sun’s surface the Moon will cover as seen by viewers in each city.

. Totality is safe to look at. During the time the Moon’s disk covers that of the Sun, it’s safe to look at the eclipse. In fact, to experience the awesomeness of the event, you must look at the Sun without a filter during totality.

Yes, the Sun’s a lot bigger. Our daytime star’s diameter is approximately 400 times larger than that of the Moon. What a coincidence that it also lies roughly 400 times farther away. This means both disks appear to be the same size.

You won’t need a telescope. One of the great things about the total phase of a solar eclipse is that it looks best to naked eyes. The sight of the corona surrounding the Moon’s black disk in a darkened sky is unforgettable. That said, binoculars give you a close-up view — but still at relatively low power — that you should take advantage of several times during the event.

Nature will take heed. Depending on your surroundings, as totality nears you may experience strange things. Look. You’ll notice a resemblance to the onset of night, though not exactly. Areas much lighter than the sky near the Sun lie all around the horizon. Shadows look different. Listen. Usually, any breeze will dissipate and birds (many of whom will come in to roost) will stop chirping. It is quiet. Feel. A 10°–15° F drop in temperature is not unusual.

Maximum totality is not the longest possible in 2017. The longest possible duration of the total phase of a solar eclipse is 7 minutes and 32 seconds. Unfortunately, the next solar eclipse whose totality approaches 7 minutes won’t occur until June 13, 2132. Its 6 minutes and 55 seconds of totality will be the longest since the 7 minutes and 4 seconds of totality June 30, 1973.

The future is bright but long. The next total solar eclipse over the continental U.S. occurs April 8, 2024. It’s a good one, too. Depending on where you are (on the center line), the duration of totality lasts at least 3 minutes and 22 seconds on the east coast of Maine and stretches to 4 minutes and 27 seconds in southwestern Texas. After that eclipse, it’s a 20-year wait until August 23, 2044 (and, similar to the 1979 event, that one is visible only in Montana and North Dakota). Total solar eclipses follow in 2045 and 2078.

This event will happen! As astronomers (professional or amateur), some of the problems we have are due to the uncertainty and limited visibility of some celestial events. Comets may appear bright if their compositions are just so. Meteor showers might reach storm levels if we pass through a thick part of the stream. (Oh, and the best views are after midnight.) A supernova as bright as a whole galaxy is visible now, but you need a telescope to view it. In contrast, this solar eclipse will occur when we say, where we say, for how long we say, and in the daytime, no less. Guaranteed!

...for those in the contiguous United States (excluding Alaska and Hawaii). The last time anyone in mainland US saw a total eclipse of the Sun was on February 26, 1979. If you live in the US and missed this event, you'll have to wait until April 8, 2024 to see a total solar eclipse from a location in the contiguous United States.

...if they were willing to drive, that is. The total eclipse was only visible along the Moon's central shadow, which at its widest was about 115 kilometers (71.5 miles), according to some sources. Its path spanned from the country's West Coast to the East Coast. The rest of North America, as well as Central America and northern parts of South America, experienced a partial solar eclipse. Prior to the eclipse, NASA estimated that a majority of the American population lives less than a 2-day drive away from the path of totality.

...if they were willing to drive, that is. The total eclipse was only visible along the Moon's central shadow, which at its widest was about 115 kilometers (71.5 miles), according to some sources. Its path spanned from the country's West Coast to the East Coast. The rest of North America, as well as Central America and northern parts of South America, experienced a partial solar eclipse. Prior to the eclipse, NASA estimated that a majority of the American population lives less than a 2-day drive away from the path of totality.

While total solar eclipses are not rare—they occur twice every 3 years on average and can be seen from some part of the Earth—a total eclipse of the Sun that can be seen from the American West Coast to the American East Coast occurs less frequently. Before the eclipse in August 2017, the last time a total solar eclipse was visible from coast to coast was almost 100 years earlier, on June 8, 1918!

...for the 2 minutes of totality. The Yaquina Head Lighthouse in Newport, Oregon was the first location on continental US soil to see totality. The partial phase of the eclipse began there at 9:04 am local time. Lincoln City, Oregon was also one of the first locations in the country to experience totality.

If you were lucky enough to be in the path of totality and the skies were clear, you probably saw the some of the features that are typical for total solar eclipses. When an eclipse begins, at 1st contact, it appears as if the Moon is taking a bite out of the Sun. As the eclipse progresses, the sky gets darker, the temperature drops, and animals and birds become quieter.

Looking at the Sun with your naked eyes is highly dangerous and can even cause blindness. The safest way to see a solar eclipse is to wear protective eclipse glasses or use a pinhole projector you can easily make yourself.

Solar eclipses occur in cycles. The Saros cycle, one of the most studied eclipse cycles, lasts for 18 years. Two solar eclipses separated by a Saros cycle have similar features—they occur at the same lunar node, with the Moon roughly at the same distance from the Earth. The eclipses also take place at about the same time of the year and around the same time of day. Eclipses that are separated by a Saros cycle are part of a Saros series.

A solar eclipse always takes place about two weeks before or after a lunar eclipse.

Two weeks before the August 21, 2017 total solar eclipse, on August 7/ 8, 2017, a partial lunar eclipse was visible from parts of South and East Asia, Europe, Africa, and Australia.