A rare solar eclipse that will be visible coast to coast across the United States has enthused everyone from professional astronomers at NASA to schoolchildren who will be allowed to go outside to view it.
Although the eclipse will darken the day at least partially across the US, Canada and Mexico, much of the excitement is centred on a band stretching across 14 states from Oregon to South Carolina.
Crowds have already gathered in cities and towns near the "zone of totality," a band about 100 kilometres wide where the sun's rays will be completely blocked by the moon. Astronomers say people can expect an eerie darkness and a drop in temperatures.
Traffic problems have already been reported in the north-west state of Oregon, where skies will begin to darken shortly after 10 am on Monday (Tuesday 0200 AEST). The eclipse will then cross the continental United States over a span of almost two hours.
The eclipse has been hyped for months because it is the first coast-to-coast solar eclipse in the United States since 1918. Numerous events are planned and broadcasters have scheduled special coverage.
The "Great American Eclipse" has also spawned an online marketing blitz for eclipse glasses, commemorative stamps and T-shirts saying "Eclipse it!"
