On Saturday, April 4, much of the world will witness the third in a tightly packed series of four total lunar eclipses. The week's event is the shortest of the four, with totality lasting less than five minutes, perfect for anyone with a limited attention span.
Lunar eclipses occur quite frequently, but many are the much less interesting penumbral or partial eclipses. Four total eclipses in sequence is unusual, although we will be seeing it more often over the next century. A minor industry has sprung up among those seeing mystical significance in that all four are visible from at least part of the United States, but so far signs of apocalypse are thin on the ground.
Saturday's eclipse will begin at 9:01 Greenwich Mean Time, dimming its light but not yet turning it red. More dramatic effects will start an hour later when part of the moon moves into the umbral shadow. The total phase will be short because the moon will pass through the edge of the Earth's shadow, not its center.
The brief total component of the eclipse will be visible from the western half of North America, eastern Asia and Australia. Anyone in South America or the eastern part of North America willing to drag themselves from their beds shortly before sunrise can see the lead-up, with some regions fortunate enough to view the partial phase as well. On the other hand, India and western China will see the moon rise as the eclipse is ending.
Credit: SockPuppetForTomruen via Wikimedia Commons. The Earth as seen from the moon during eclipse totality.
For the rest of the world, the Slooh Community Observatory will be offering a live feed from multiple sites where the eclipse can be seen. Watch it live here:
The eclipse this September, completing the tetrad, will occur at almost exactly the opposite side of the Earth, visible from almost everywhere that will miss out on this one.