A solar eclipse will occur on Aug. 21, 2017, and for the first time since 1919, will be visible across the continental United States. The University of Florida is ready to gather for this unique event and its astronomy department is making available to the public its four 8-inch Meade telescopes fitted with safe solar filters.
To see the eclipse in its "total" form, one must be in the path of totality, which approximately spans South Carolina to Oregon in a diagonal swath. The sun will obscured for up to two minutes and 40 seconds, depending on where you stand in the path. For those in the path of totality, the effect is that someone turned out the light, and it's suggested that you bring a sweater.
Gainesville, Fla. is outside the path of totality (100% shadow), but will still experience 87 percent of the total effect. UF astronomer Peter Barnes will be at the Campus Teaching Observatory to answer questions; meanwhile, Professor Francisco Reyes will join the "EclipseMob," a team working at 28 stations across the path of totality, measuring how deionization during the eclipse will affect the galactic radio background.
14: Number of states in the path of totality in the 2017 eclipse.
67: Number of miles wide the path of totality will measure.
10:16: The time in the morning on the West Coast when the eclipse begins.
2:48: The time in the afternoon on the East Coast when the eclipse concludes.
1979: Last time a solar eclipse was visible in the U.S.
1919: Last time a solar eclipse was visible coast-to-coast.
375: Numbers of years between when any given spot is in the path of totality.
428: The duration in seconds of the longest eclipse in history (just over 7 minutes) in 1955.
There are two orbits at play in any eclipse involving our planet: Earth's orbit around the sun, and the Moon's orbit around Earth. When these orbits cross during "eclipse season" is when eclipses may occur. The orbital plane of the Moon is at a five-degree tilt relative to Earth's; if there were no tilt, there would be a lunar eclipse at every full moon, when the Earth is between the Sun and the Moon, and a solar eclipse at every new moon, when the Moon moves in between the Sun and the Earth.
Solar eclipses can only happen at or after a new moon, when the Moon and the Sun have the same ecliptical longitude, i.e. the same distance on the ecliptic from the point of the vernal equinox. This effectively means the Moon is close enough to intercepting the Sun and Earth that the Sun's light only shines on the Moon's side facing away from Earth. On rare occasions, the orbits actually do align, and a solar eclipse occurs.
Between where the external lines of the Sun's light intersect with each other's inner lines is the "umbra" (from Latin for "shade,"), which effectively creates total blackout, or the totality of the eclipse. The outside part of the shadow is the "penumbra," with the Latin prefix "pen-" meaning "almost."
In many ancient Asian and American civilizations, an eclipse was interpreted as a creature, usually a dragon or demon, consuming the Sun, or a sign of the apocalypse. Understanding that the Sun gives life-supporting light, people throughout history widely regarded solar eclipses as bad omens or dangerous events.
Many religious scholars and painters have interpreted Biblical references to a sky that darkened upon Jesus' crucifixion as an eclipse, whether solar or lunar.
The 1889 novel A Connecticut Yankee in King Arthur's Court is a time-travel satire in which the protagonist uses an eclipse to his advantage. Mark Twain may have been inspired by the reported use by Christopher Columbus' reported use of an ephemeris to extort the Taíno of Jamaica, by threatening an eclipse (which happened as he said it would) if they did not comply.
The plot device of a fortuitously convenient eclipse also appeared in Tintin: The Prisoners of the Sun, a 19xx comic-turned-19xx film, steeped in (fairly exoticized) Incan culture. Similarly, the Mayan* hero in Apocalypto (2006, dir. Mel Gibson) is able to escape inevitable execution when an eclipse darkens the world.
The TV show Angel's fourth season (2002) features a demon who performs a ritual to blot out the sun, which allows vampires to roam 24/7. In an earlier portrayal of creatures of the night experience an eclipse, Ladyhawke (1985, dir. Richard Donner) imagines how were-creatures would encounter each other during a solar eclipse.
In Fantasia (1940), Igor Stravinsky's "The Rite of Spring" is visualized in an animated scene that uses an eclipse as a metaphor for the transformation and renewal that comes with the change of seasons.
Steven King's Dolores Claiborne (1992; film adaptation 1995, dir. Taylor Hackford) is a psychological thriller set against the July 20, 1963 eclipse, which also appeared in King's 1992 book Gerald's Game.
Barabbas (1961, dir. Richard Fleischer) is unique in that it features an actual solar eclipse as the background to a depiction of Jesus' crucifixion.
*Unfortunately, few of these works bother to highlight the notable distinctions among the Taíno (14th century CE to present, Caribbean), Maya (2000 BCE to 17th century CE, with living descendants, Mexico, Guatemala, and Belize), and Inca (12th century to 16th century CE, Peru).