Search results
Results from the WOW.Com Content Network
Sunrise, sunset, or sun position for any location – U.S. only; Sunrise, sunset and day length for any location – Worldwide; Rise/Set/Transit/Twilight Data – U.S. only; Astronomical Information Center; Converting Between Julian Dates and Gregorian Calendar Dates; Approximate Solar Coordinates; Algorithms for Computing Astronomical Phenomena
Twilight Calculator Compute twilight times. Twilight time calculator Archived 2011-10-14 at the Wayback Machine; Formulae to calculate twilight duration (archived) by Herbert Glarner. The colors of twilight and sunset; HM Nautical Almanac Office Websurf Compute twilight times. Geoscience Australia "Sunrise and sunset times" Compute twilight times.
Blue hour at the Old Cathedral of the Holy Name of Jesus, Bragança in Portugal. The blue hour (from French l'heure bleue; [1] [a] pronounced [lœʁ blø]) is the period of twilight (in the morning or evening, around the nautical stage) when the Sun is at a significant depth below the horizon.
US Navy Twilight time calculator : "For computational purposes, sunrise or sunset is defined to occur when the geometric zenith distance of center of the Sun is 90.8333 degrees. That is, the center of the Sun is geometrically 50 arcminutes below a horizontal plane.
Diagram showing displacement of the Sun's image at sunrise and sunset Comparison of inferior and superior mirages due to differing air refractive indices, n. Atmospheric refraction is the deviation of light or other electromagnetic wave from a straight line as it passes through the atmosphere due to the variation in air density as a function of height. [1]
Earth's terminator as seen from space. A terminator or twilight zone is a moving line that divides the daylit side and the dark night side of a planetary body.The terminator is defined as the locus of points on a planet or moon where the line through the center of its parent star is tangent.
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
Twilight patterns are produced during the time period between the beginning of astronomical twilight (when the Sun is 18° below the horizon) and sunrise, or sunset and the end of astronomical twilight. The duration of astronomical twilight depends on the length of the path taken by the Sun below the horizon.