Because of parallax, the Moon's position against the background stars will look a bit different for observers at different locations on the surface of the Earth. An hour later, entirely within the umbra, the Moon is a ghostly copper color, and this lasts for over an hour before the Moon begins to emerge from the central shadow.The view in these animations is geocentric. The real action begins when the Moon starts to disappear as it enters the umbra at about 9:07 Eastern Daylight Time. The Moon's appearance isn't affected much by the penumbra. The umbra is where the Sun is completely hidden. Just go outside and look up!The penumbra is the part of the Earth’s shadow where the Sun is only partially covered by the Earth. You won’t need special equipment to see it. Versions of the animation have been created for each of the four time zones of the contiguous United States, as well as one for Universal Time.All of South America and most of North and Central America will see the entire eclipse, while those west of roughly 120°W will see it in progress at moonrise. This animation shows the changing appearance of the Moon as it travels into and out of the Earth’s shadow, along with the times at various stages. ![]() || On the evening of Septemin the Americas (early morning on September 28 in Europe and most of Africa), the Moon enters the Earth’s shadow, creating a total lunar eclipse, the last of four visible in the Western Hemisphere in a span of 18 months. The Moon moves right to left, passing through the penumbra and umbra, leaving in its wake an eclipse diagram with the times at various stages of the eclipse. The relative sizes of the Earth and Moon in the main orbit graphic are exaggerated by a factor of 15 to make them more easily visible. The Moon graphic in the upper left shows the change in the Moon's apparent size as it moves closer and farther in its orbit, as well as its copper color during the eclipse. It ends on September 28, the day of the supermoon eclipse, when the distance to the Moon is 28 Earth diameters. It then shows apogee on September 14, when the Moon is almost 32 Earth diameters away. There will be seven more supermoon eclipses in this series, the last in December of 2141.The animation begins at the end of August showing that perigee and Full Moon miss each other by about a day. The 2015 supermoon eclipse is the first in Saros 137. Eclipses separated by this period tend to share certain properties and are grouped into families, or saros series. Only then does the Moon's orbit carry it close enough to the Earth-Sun line to actually pass through the shadow cast by the Earth.A supermoon eclipse requires the alignment of all three cycles, the synodic, anomalistic, and draconic months, and this happens every 18 years 11 days, a period known as a saros. Total lunar eclipses happen when a node crossing coincides with a Full Moon. The Moon's tilted orbit crosses the Earth-Sun plane at one of two points called nodes a draconic month is the time it takes the Moon to return to the same node. The anomalistic month - the time between two perigees - is two days shorter than the cycle of phases, called the synodic month the perigees "lap" the phases after 14 months.Total lunar eclipses involve a third cycle, the draconic month. The Moon makes first contact with the umbra, the central part of the Earth's shadow, at 1:07 UT, and it doesn't completely emerge until 4:27 UT.If we define a supermoon as a Full Moon that coincides with the closest perigee in a given year, then supermoons occur every 14 months, with occasional skips. This is only an hour before the time of peak full Moon at 2:51 UT, when the Moon's ecliptic longitude differs from the Sun's by exactly 180 degrees.All of this takes place during a total lunar eclipse. The closest perigee for 2015 occurs on September 28 at around 1:52 Universal Time, when the Moon will be 356,877 kilometers (221,753 miles) away. ![]() Some perigees are a little closer than others. ![]() Each month, the Moon passes through points in its orbit called perigee and apogee, the closest and farthest points from the Earth for that month. As it happens, this largest Full Moon occurs within the Earth's shadow, creating the added spectacle of a total lunar eclipse.The Moon's orbit is very slightly elliptical and therefore somewhat off-center relative to the Earth. || On Septem(the night of the 27th in many places), the Moon will be full at the same time that it is closest to Earth for the year, a coincidence sometimes called a supermoon. ![]() Frame sequences with alpha channel are available for the separate elements of the animation.This video is also available on our YouTube channel. The inner blue circle shows perigee distance, the outer blue circle shows apogee distance, and the off-center, light gray circle shows the Moon's orbit. The geometry of the Moon's orbit in motion, from the end of August until the supermoon eclipse on September 27-28, 2015.
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