World map with terminator (April)

A composite image showing the terminator dividing night from day, running across Europe and Africa. Observers on the surface of the earth along this terminator will see a sunset.

Photograph of part of the terminator crossing the surface of the Earth, as seen from the ISS. The terminator is diffuse and shows the gradual transition to darkness that is experienced as twilight on the surface.

The terminator is the line between the illuminated, day side and dark, night side of a planetary body (also known as the "grey line" or the "twilight zone"). It is defined as the locus of points on a moon or planet where the line through the sun is tangent. The line separates the portions of the earth experiencing daylight from the portion of the planet experiencing darkness. While one half of the earth is illuminated at any point in time, the location of the terminator line varies by time of day due to the rotation of the earth on its axis as well as the revolution of the earth around the sun. The seasons impact the location of the terminator line most dramatically. Image File history File links Download high resolution version (982x562, 871 KB) World map showing daylight around 13:00 UTC, April 2nd. ... Image File history File links Download high resolution version (982x562, 871 KB) World map showing daylight around 13:00 UTC, April 2nd. ... Download high resolution version (1024x1024, 143 KB) Wikipedia does not have an article with this exact name. ... Download high resolution version (1024x1024, 143 KB) Wikipedia does not have an article with this exact name. ... World map showing Europe A satellite composite image of Europe Europe is one of the seven continents of the Earth. ... A world map showing the continent of Africa. ... Image File history File links Download high resolution version (3060x2092, 731 KB) Summary No sudden, sharp boundary marks the passage of day into night in this gorgeous view of ocean and clouds over our fair planet Earth. ... Image File history File links Download high resolution version (3060x2092, 731 KB) Summary No sudden, sharp boundary marks the passage of day into night in this gorgeous view of ocean and clouds over our fair planet Earth. ... ISS redirects here. ... It has been suggested that this article or section be merged with Dawn. ... In mathematics, a locus (Latin for place, plural loci) is a collection of points which share a common property. ... Adjective lunar Bulk silicate composition (estimated wt%) SiO2 44. ... The eight planets and three dwarf planets of the Solar System. ... The Sun is the star of our solar system. ... In mathematics, the word tangent has two distinct but etymologically-related meanings: one in geometry and one in trigonometry. ... This article is about divisions of a year. ...

In the frame of reference of a rotating planet, the terminator sweeps across the surface of the planet bringing sunrise on one side of the planet and sunset on the opposite side. The eight planets and three dwarf planets of the Solar System. ... The Rayleigh effect, seconds before sunrise in New Zealand Sunrise, also called sunup in some American English dialects, is the time at which the first part of the Sun appears above the horizon in the east. ... The eight planets and three dwarf planets of the Solar System. ... A composite image showing the terminator dividing night from day, running across Europe and Africa. ...

Examination of the terminator can yield information about the surface of the body; for example, a fuzzy terminator indicates the presence of an atmosphere. Atmosphere is the general name for a layer of gases that may surround a material body of sufficient mass. ...

On the spring and fall equinoxes (around March and September 21), there is no tilt of the earth with respect to the sun so the terminator line is parallel with the axis of the earth and with the lines of longitude. In astronomy, an equinox is defined as the moment when the sun reaches one of two intersections between the ecliptic and the celestial equator. ... Earth (IPA: , often referred to as the Earth, Terra, the World or Planet Earth) is the third planet in the solar system in terms of distance from the Sun, and the fifth largest. ... Map of Earth showing lines of longitude, which appear curved and vertical in this projection, but are actually halves of great circles Longitude, sometimes denoted by the Greek letter λ, describes the location of a place on Earth east or west of a north-south line called the Prime Meridian. ...

The terminator line is at its greatest angle with respect to the axis on the winter and summer solstices (around December and June 21), when it is approximately 23.5 degrees off the axis. Solstice is an astronomical term regarding the position of the Sun in relation to the celestial equator. ...

Excluding travel near the poles, the Concorde was the only passenger airliner able to overtake the terminator. On certain early evening transatlantic flights departing from Heathrow or Paris, it was possible to take off at night and catch up with the sun — from the cockpit you could see the sun rise in the west. The Aérospatiale-BAC Concorde supersonic transport (SST), along with the Tupolev Tu-144, was one of only two models of supersonic passenger airliners to have seen commercial service. ...

External links

• Current terminator
• aa.usno.navy.mil Website calculing synthesic images (B&W or color) representing the terminator for a given time (date & hour)