On September 27, 2015, skywatchers will enjoy a total lunar eclipse at “Supermoon”, when the Moon makes its closest approach to Earth and appears largest in the sky. Slooh members can join us for live coverage of this “Supermoon” eclipse on the evening of September 27.

During a lunar eclipse, the Moon passes into the Earth’s shadow. But it doesn’t completely go dark.That’s because the Sun’s light is refracted and scattered forward through our atmosphere and onto the Moon’s surface. Red light scatters least, so the Moon often takes on a striking dull red or copper color during a total lunar eclipse.

The September 27 eclipse will be the fourth and last eclipse of a tetrad, a series of four consecutive total lunar eclipses over two years. The first three were on April 15 and October 8 in 2014, and April 4, 2015. During this final eclipse of the tetrad, the Moon will appear nearly 13% larger than the total lunar eclipse of April 4, 2015, which occurred when the Moon was at its furthest from Earth. The April 4 eclipse lasted less than five minutes, but the September 28 “Supermoon” eclipse will last some 72 minutes, reaching totality 02:47 UT. The eclipse will be visible from beginning to end in central and eastern North America, all of South America, and western Europe. In western North America, the Moon will rise as the eclipse is in progress.

Some call the reddened Full Moon at eclipse a “Blood Moon”. Since this eclipse occurs at a “Supermoon”, some may no doubt call this a “Blood Supermoon”. But whatever you call it, this will be an event to remember. Mark your calendars to join Slooh for coverage of this total lunar eclipse on September 27.