It is an astronomical quirk occuring once every five hundred years.
A lunar eclipse occurs when the sun, Earth and moon line up so the Earth’s shadow falls on the moon, darkening it.
Eclipses are one of the few astronomical events that can easily be enjoyed with the naked eye. The Earth’ s shadow makes a slow crawl across the moon’s face, appearing as if there is an increasingly large ‘bite’ taken out of the moon.
The moon is covered with reddish brown color
The bloody red color the moon takes on during an eclipse is caused by refraction of sunlight by the Earth’s atmosphere. It is the same effect that you see when the sun turns reddish-orange at sunset, only in this case the refracted sunlight projects all the way to the moon.
This eclipse also features an extra astronomical quirk. Mars appears as a fiery red ‘star’ next to the moon. Together red Mars and the red shadow on the moon’s face should be a spectacular sight and an incredible photo opportunity.
The only downside to this month’s lunar eclipse is that it comes very late at night for most of America.
The first Blood Moon eclipse in a series of four occured on the night of April 14-15, 2014. This total eclipse of the moon was visible from the Americas. We in astronomy had not heard the term Blood Moon used in quite this way before this year, but now the term is becoming widespread in the media. The origin of the term is religious, at least according to Christian pastor John Hagee, who wrote a 2013 book about Blood Moons.
What is a lunar tetrad?
It’s four successive total lunar eclipses, with no partial lunar eclipses in between, each of which is separated from the other by six lunar months (six full moons).