During a total eclipse, observers can see the solar corona, a superheated plasma 2 million degrees in temperature.
Contrast that to the 21 century, when we'll see six widely visible total solar eclipses starting this year and ending in 2099.
Scientists and amateur astronomers have been using NASA data to plan their eclipse trips for years. With the total solar eclipse right around the cosmic corner, eye doctors are going into nagging overdrive. It will start in Texas and go in a northeast direction, through OH and up into Canada. Please note that the library will close for an hour so employees can be outside when the total eclipse occurs.
In Oregon, that sense of awe will greet members of Generation Eclipse on the Warm Springs Indian Reservation, where 13 teams of primarily Native American kids will gather in the path of totality to release weather balloons during the eclipse.
On Aug. 21, a total solar eclipse will be visible in a band about 65 miles wide stretching from OR to SC.
First caveat: You must be in the path of totality to even consider this.
NASA photographer Bill Ingalls recommends focusing on the human experience of watching the eclipse. At maximum, a sliver of light will remain in the upper left corner of the sun.
The sudden, albeit brief, transformation from day into night has elicited odd behavior in animals in the past.
So it's time to rustle up special eclipse eyewear to use August 21, when the USA has its first full solar eclipse spanning coast to coast in 99 years. Eventually, the moon's disk will no longer cover the sun during an eclipse.
Stretching from roughly 50 to 400 miles above Earth's surface, the tenuous ionosphere is an electrified layer of the atmosphere that reacts to changes from both the Earth below and space above.
How to watch August solar eclipse in Arizona
A solar eclipse can only happen during a new moon.
The careful observation of the moon's shadow "will make more precise computations possible next time", a New York Times reporter wrote. I'll be talking more about it and my physics students will be doing calculations related to the eclipse and things we can figure out from it. With your back to the sun, look at your hands' shadow on the ground. Under normal conditions, the corona can not be seen from the ground because it is overwhelmed by the brightness of the sun's main disk, the photosphere.
To help the community safely view the August 21 eclipse, Yorkshire Eye Clinic is giving away free eclipse glasses on a first-come, first-serve basis.
Those in southern IL, near Carbondale, can catch the total eclipse. Before and after totality, eye protection is necessary for anyone in the narrow path of totality.
It may be tempting to take the glasses off, to just view the eclipse using the clouds as a filter. Sunglasses are not sufficient.
To be clear, totality means 100 percent of the sun is covered.
Today, we know the moon's precise contours and orbit, and can accurately predict an eclipse's timing and its path down to the scale of a city block. Only when the moon is completely covering the sun can spectators remove their glasses. During a partial solar eclipse, the sun is not almost as bright, so the temptation is to stare at the sun for too long a time.
If you really don't want to look up at the sun, you can look down instead with a quick DIY project.
There are ways of enjoying one of nature's greatest shows. These should not be used in conjunction with any magnifying instruments such as telescopes or binoculars, since those will intensify the sunlight and can cause the goggles to break from the intense heat. Use the hashtag #Eclipse2017 and tag @NASAGoddard to connect your photos on social media to those taken around the country and share them with NASA.
Paper glasses with special filters made of protective material are being sold in countless outlets.