Solar eclipses have been blamed in the past for war, famine, and the deaths of kings. But the upcoming total eclipse on August 1 will mostly be celebrated by excited sky-watchers--even if it won't break any records.
The sun will be completely obscured for just under two and a half minutes, "a tad on the short side," according to astrophysicist Fred Espenak, an eclipse expert based at the NASA Goddard Space Flight Center.
A typical eclipse lasts for three minutes, Espenak said, and the longest possible is seven and a half minutes.
When it starts, this year's full eclipse will be visible from a narrow arc spanning the Northern Hemisphere.
Its path will begin in Canada and continue northeast across Greenland and the Arctic, then southeast through central Russia, Mongolia, and China.
The eclipse will start around 8:30 a.m. Greenwich mean time in the eastern part of the arc, leading to totality in just under an hour.
In a much wider swath of the globe--including northeastern North America along with most of Europe and Asia—people will be able to see a partial eclipse.
Drop Dead Gorgeous
The moon crosses between Earth and the sun once a month during the new moon. For an eclipse to happen, the moon has to come directly between the two bodies--it can't be too high or low relative to Earth. (See photos of the full moon from Earth and space.)
Sometimes the moon will be close enough that just an edge will pass in between, resulting in a partial eclipse.
About 25 percent of eclipses are total eclipses, and there are about seven of these a decade, Espenak said. But at any given geographic location, a total eclipse will be visible an average of once in 375 years. The last solar eclipse visible from the United States was in 1979, and it was seen mostly in the Pacific Northwest.
When a total solar eclipse takes place, about half the daytime world doesn't see any of it, Espenak said. Another 49 percent of people see it as a partial eclipse.
Less than one percent of people see totality, which Espenak describes as "drop dead gorgeous."
"On a scale of one to ten, a partial eclipse is of some interest," he said. "A total eclipse on that scale is ten million. It can't be compared to anything else. It should be on everybody's life list."