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Predictions for the 2004 Transit of Venus
Fred Espenak, NASA's GSFC and Jay Anderson, Environment Canada, the 17/03/04

Visibility of the Transit

The transit will be visible from the entire daylight hemisphere of Earth. But since the event lasts over six hours, Earth will rotate 1/4 revolution between the times of ingress and egress. Consequently, some geographic areas will see the entire transit while others witness only part of the event (including either ingress or egress). Finally, about a quarter of Earth will see none of the transit since the Sun will be below the horizon throughout the entire period.

At ingress (Figure 2 - Small Size, Large Size ), the transit will be observable from all of Asia, Australia, Europe, and high northern latitude including Alaska, northern Canada, Greenland and Iceland.


Figure 2


At greatest or mid-transit, the event will be visible from Europe, Africa, Asia, western Australia, and high northern latitudes. At egress, the transit will be observable from all of Africa, Europe, central Asia, eastern North America, northern South America, and high northern latitudes including Greenland, Iceland and northern Canada.

As Earth rotates, the Sun will set before the transit ends from Japan, Indonesia, the Philippines, Australia and easternmost Asia, so these regions will miss egress. Similarly, locations in western Africa, eastern North America, the Caribbean and northern South America will find the transit already in progress as the Sun rises. As a result, these locales will miss ingress.

The entire transit is observable from Europe, north and east Africa, and Asia (except far east). In contrast, none of the transit will be seen from western North America, the eastern Pacific (including Hawaii), southern South America (Chile and southern Argentina) and Antarctica. Western states in the U. S. which miss the transit include: Arizona, California, Colorado, Idaho, Nevada, New Mexico, Montana, Oregon, Texas, Utah, Washington and Wyoming.

The world visibility map depicts the geographic locations from which each phase of the transit is visible. This map does not include refraction, which could increase the region of visibility by about half a degree.

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