Total Lunar Eclipse Over, Next One in August 28 This Year

The spectacular total lunar eclipse that took place last week-end gathered millions of sky-gazers, in Europe, Africa and the Middle East, but those who missed it will have another chance this summer.

A lunar eclipse occurs whenever the Moon passes through some portion of the Earth's shadow. This can occur only when the Moon is full, and when the Sun, Earth and Moon are aligned exactly, or very closely so.

The most recent total lunar eclipse was on 3 March 2007 to 4 March 2007. It was L=3 to L=4 on the Danjon scale (a five-point scale useful for measuring the appearance and luminosity of the Moon during a lunar eclipse), it was fully visible over Europe and Africa and at least partly visible over the eastern Americas, Asia, and western Australia. The moon entered the penumbral shadow at 20:18 UTC, and the umbral shadow at 21:30 UTC. The total phase lasted between 22:44 UTC and 23:58 UTC. The moon left the umbra shadow at 01:11 UTC and left the penumbra shadow at 02:24 UTC 4 March 2007.

The most fortunate were the British, who, besides having the best position from Earth to observe this particular eclipse, also enjoyed a crystal-clear sky. During “totality” the Moon took on a reddish hue; the only light reaching its surface by this stage had been filtered through Earth’s atmosphere.

The reddish glow was “the sunlight still reaching the moon after being refracted through the Earth's atmosphere” Sagan explained. The Sun being much larger, the shadow of the Earth is conical with a lighter outer region called 'penumbra' and the darkest part in the center - called the 'umbra'.

The reddish color of the Moon was caused by the quantity of dust that exists in the upper levels of Earth’s atmosphere. Had there been a major volcanic eruption, the Moon would have had a deep red appearance, thus becoming almost invisible. Since no volcanic eruption took place, the Moon got the reddish hue only at the peak of the eclipse. The reason that the Moon can be seen at all during totality is that sunlight is scattered and refracted around the edge of the Earth by our atmosphere. There have been gradations in hue between the parts of the disk nearest and farthest from the shadow center.

Robin Scagell, of the Society for Popular Astronomy, said- quoted by British tabloid The Sun- that it was “one of the best lunar eclipses from Britain for years”.

He said: “It was fascinating to watch the Moon’s graceful movement through the shadow of the Earth and check its coppery glow.”

The eclipse from March 3 was the only one Britain inhabitants could watch without worrying about the weather. The last eclipse visible in the insular territory took place in 2004, but was obnubilated by heavy clouds.

According to an Associated Press report, about a dozen amateur astronomers braved the cold and mud outside the Croydon Observatory in southeast London to watch the start of the eclipse. "It was really very dark," said Paul Harper, Chairman of the Croydon Astronomical Society, who estimated that moon had lost over four-fifths of its luminosity. "It was quite a nice one.

Unlike an eclipse of the Sun which often requires a long journey to the path of totality, those of the Moon can be observed from one’s own backyard. The passage of the Moon through the Earth’s shadow is equally visible from all places within the hemisphere where the Moon is above the local horizon. The beginning and ending of a lunar eclipse happens simultaneously for every viewer, unlike an eclipse of the Sun.

The next total lunar eclipse is expected to occur in August 28, and is also expected to be longer than the one we have witnessed last week. If the one on March 3 lasted for 3h and 14m, the one in August will last 3h and 31m and will be visible in Asia, Australia Oceania and the Americas.