On Tuesday, the sky is putting on one of the more spectacular celestial shows, a total eclipse of the sun.
For a brief moment over the southern Pacific, the moon will move directly between the us and the sun, blocking out all direct light and casting a shadow about 100 miles wide on the Earth's surface.
Witnesses in its path will experience a dusk-like atmosphere, just an hour after the sun rises. For the unprepared (and the animal population, which reacts with confusion to the sudden return to darkness), a total eclipse can be as disconcerting as it is beautiful.
Unfortunately, it will only be visible in a remote corner of a remote continent--Queensland, Australia--along a narrow path cutting across the north-east corner of Australia and heading south east out across the Pacific ocean. The only city that will have a full view of totality is Cairns, although it will also be visible along the coast near the Great Barrier Reef.
The rest of Australia, as well as New Zealand, Antarctica, and parts of South America, will be able to see a partial eclipse, viewing the moon from an angle where it covers part, but not all, of the solar disc.
Totality--the brief moment when the moon is perfectly aligned between the Earth and the sun and covers it completely--will begin around 6:35 a.m. Wednesday, local time, or 3:35 p.m. EST on Tuesday. Over land, it will last just two minutes, stretching as long as four minutes over open ocean further down the eclipse's path.
In those few minutes only will it be safe to look directly at the sun, which will appear as a black disc surrounded by the brilliant glow called the corona.
On either side of totality, a phenomenon called the Baily's beads effect, culminating in the spectacular diamond ring, occurs. As the last (and then, first) direct sunlight shines through the craters on the face of the moon. The bright "bead" of light, along with the ring of the corona, looks like a celestial version of the jewelry for which is is named.