In some ancient and modern cultures, solar eclipses were attributed to supernatural causes or regarded as bad omens.

[6] Partial eclipses are virtually unnoticeable in terms of the Sun's brightness, as it takes well over 90% coverage to notice any darkening at all.

It is possible, though extremely rare, that part of the umbra intersects with Earth (thus creating an annular or total eclipse), but not its central line.

Therefore, the Moon's apparent size varies with its distance from Earth, and it is this effect that leads to the difference between total and annular eclipses.

This regression means that the time between each passage of the Moon through the ascending node is slightly shorter than the sidereal month.

[25] Finally, the Moon's perigee is moving forwards or precessing in its orbit and makes a complete circuit in 8.85 years.

This is referred to as an eclipse limit, and is given in ranges because the apparent sizes and speeds of the Sun and Moon vary throughout the year.

[34]: Chapter 11 Calculations with Besselian elements can determine the exact shape of the umbra's shadow on Earth's surface.

Observers aboard a Concorde supersonic aircraft were able to stretch totality for this eclipse to about 74 minutes by flying along the path of the Moon's umbra.

The most notable difference will be a westward shift of about 120° in longitude (due to the 0.3 days) and a little in latitude (north-south for odd-numbered cycles, the reverse for even-numbered ones).

Even on Earth, the diversity of eclipses familiar to people today is a temporary (on a geological time scale) phenomenon.

[47] Estimates of the time when the Moon will be unable to occlude the entire Sun when viewed from Earth range between 650 million[48] and 1.4 billion years in the future.

[53] Especially, self-made filters using common objects such as a floppy disk removed from its case, a Compact Disc, a black colour slide film, smoked glass, etc.

[57] A kitchen colander with small holes can also be used to project multiple images of the partially eclipsed Sun onto the ground or a viewing screen.

Securely mounting #14 welder's glass in front of the lens and viewfinder protects the equipment and makes viewing possible.

If three-quarters or more of the Sun is obscured, then an effect can be observed by which the daylight appears to be dim, as if the sky were overcast, yet objects still cast sharp shadows.

As with viewing the Sun directly, looking at it through the optical viewfinder of a camera can produce damage to the retina, so care is recommended.

Using a camera's live view feature or an electronic viewfinder is safe for the human eye, but the Sun's rays could potentially irreparably damage digital image sensors unless the lens is covered by a properly designed solar filter.

The legendary Chinese king Zhong Kang supposedly beheaded two astronomers, Hsi and Ho, who failed to predict an eclipse 4000 years ago.

[74] The ancient Greek historian Herodotus wrote that Thales of Miletus predicted an eclipse that occurred during a battle between the Medes and the Lydians.

[83] Attempts have been made to establish the exact date of Good Friday by assuming that the darkness described at Jesus's crucifixion was a solar eclipse.

This research has not yielded conclusive results,[84][85] and Good Friday is recorded as being at Passover, which is held at the time of a full moon.

[86] In the Western hemisphere, there are few reliable records of eclipses before AD 800, until the advent of Arab and monastic observations in the early medieval period.

"[87] The Cairo astronomer Ibn Yunus wrote that the calculation of eclipses was one of the many things that connect astronomy with the Islamic law, because it allowed knowing when a special prayer can be made.

Now whether the robber carries off the light in the evening when Indra has gone to sleep, or boldly rears his black form against the sky during the daytime, causing darkness to spread over the earth, would make little difference to the framers of the myth.

[89]A total solar eclipse provides a rare opportunity to observe the corona (the outer layer of the Sun's atmosphere).

By comparing the apparent distance between stars in the constellation Taurus, with and without the Sun between them, Arthur Eddington stated that the theoretical predictions about gravitational lenses were confirmed.

[97] Observation during the 1997 solar eclipse by Wang et al. suggested a possible gravitational shielding effect,[98] which generated debate.

At one time, some scientists hypothesized that there may be a planet (often given the name Vulcan) even closer to the Sun than Mercury; the only way to confirm its existence would have been to observe it in transit or during a total solar eclipse.

At the altitude of the International Space Station, for example, an object would need to be about 3.35 km (2.08 mi) across to blot the Sun out entirely.