Due to time zone differences, most locations in Mainland United States will be treated to a striking Total Lunar Eclipse on the night of September 27, 2015, weather permitting. People on the U.S. East Coast and parts of Central United States will have some of the best views of the Eclipse, which will occur after moonrise and before local midnight (00:00 on September 28). At some locations in Eastern US, the last stages of the Eclipse will occur after midnight on September 28 .
Lunar eclipses usually do not occur in any specific order. However, every once in a while, four total lunar eclipses happen in a row. This is called a lunar tetrad. The total lunar eclipses happen 6 months apart. There are at least six full Moons between two total lunar eclipses in a tetrad.
The first three total eclipses in this lunar tetrad occurred on
April 15, 2014,
October 8, 2014,
and April 4, 2015.
According to NASA, the current century – 2001 to 2100 – will have eight tetrads. The first tetrad of the 21st century took place in 2003, and the second will happen in 2014-2015.
Depending on weather conditions on September 28, lucky viewers will see a full moon that looks larger and brighter than usual, with a red tinge.
It will be first ‘supermoon’ lunar eclipse since 1982 and there won’t be another until 2033, according to NASA.
The moon looks larger at times because of the moon’s orbit around our planet is elliptical, so while its average distance from the Earth is 239,000 miles (384,600 kilometres) it can get as close as 226,000 miles (363,700 km) at the closest point, or perigee, Space.com explained.
In recent years, the term Blood Moon has been frequently used to refer to Total Lunar Eclipses. Some sources suggest that the origin of the term in the context of the 2014-2015 lunar tetrad can be traced to Christian pastors Mark Blitz and John Hagee, who claim that the eclipses fulfill a Biblical prophecy of forthcoming difficult and trying times. These two pastors speak of a lunar tetrad as representing a fulfillment of Biblical prophecy. As described in Joel 2:31 (Common English Bible):
The sun will be turned to darkness, and the moon to blood before the great and dreadful day of the LORD comes.
Astronomers on the other hand, do not use Blood Moon as a scientific term, though it is possible that the term came to describe Total Lunar Eclipses because of the reddish color the eclipsed Moon takes on during totality. This happens because of Rayleigh scattering, the same mechanism that causes colorful sunrises and sunsets and the sky to look blue.