Excitement is building over the first total solar eclipse visible in the United State in nearly four decades. And rightfully so.

The eclipse is rare for its accessibility because these occurrences fall over water or unpopulated regions of the planet, according to Space.com.

An eclipse happens when the moon moves directly between the earth and the sun. The unique moment arriving Monday is that scientists say it will be the first total solar eclipse whose path will start completely in the United States since 1776, the year the American Declaration of Independence was written.

Many interesting discoveries and odd things have been attributed to a total eclipse of the sun throughout history, according to various scientific and historical research sites, such as timeanddate.com. British astronomer and mathematician, Sir Arthur Eddington, used the total solar eclipse of May 29, 1919 to test Albert Einstein’s theory of general relativity. By taking pictures of stars near the sun during totality, Eddington was able to show that gravity can bend light. This is called gravitational deflection.

On Aug. 16, 1868, French astronomer Jules Janssen discovered helium during a solar eclipse. Helium, because of the sun’s role in revealing the second lightest element known to humans, takes its name from the Greek word for sun, helios.

Ancient records show the Babylonians and Chinese were able to predict solar eclipses as early as 2500 BC. Through research of even older writings, scientists believe humans documented solar eclipses on ancient petroglyphs as far back as 5000 BC.

Greek historian Herodotus wrote that a solar eclipse in 585 BC stopped the war between the Lydians and the Medes, who saw the dark skies as a sign to make peace with each other. The Greek astronomer Hipparchus used a solar eclipse to determine that the moon was about 268,000 miles away from the earth. This is only about 11 percent more than what today’s scientists accept as the average distance between the moon and the earth.

Whether anything significant will come from Monday’s solar eclipse remains to be seen.

With all the strife gripping the United States, the eclipse will pull the shade down over the nation for a brief time for a truly unique and rare show in the heavens.

By all means, enjoy this unusual moment in history. It’s not expected again for a long time in this particular fashion. And be sure to use your solar eclipse glasses if you choose to watch the sun’s disappearance.