The longest and darkest total lunar eclipse of the century will occur today , giving sky enthusiasts all over the country an opportunity to witness the event.
An unusually long lunar eclipse with the Moon immersed deeply inside the umbral (darker) shadow of the Earth will occur tomorrow, Nehru Planetarium Director N Rathnasree said.
"The total phase of this lunar eclipse will last 100 minutes. The last eclipse to exceed this duration was in July 2000," she said.
The next such eclipse will only take place in 2141.
The total lunar eclipse will begin at 00:52:30 IST and end at 02:32:42 IST. While the partial eclipse will begin at 23:52:56 IST and end at 03:32:15 IST.
The eclipse will be visible completely in Africa and Central Asia. It will be visible rising over South America, Western Africa and Europe, and seen setting over Eastern Asia, and Australia, C B Devgun from Science Popularisation Association of Communicators and Educators (SPACE) said.
The magnitude of the one of the relatively rare total lunar eclipse will be 1.70 magnitude, N Sri Raghunandan Kumar of Planetary Society of India said.
The next lunar eclipse to be viewed in India will be in December this year.Also, a star named 51 Ophiuchi will be occulted during the eclipse.
Sky enthusiasts can witness the whole sequence of the occultation in the zodiacal constellation of Ophiuchus.
At 11:29 PM tomorrow, the Moon will occult (hide) behind the star 51 Ophiuchi. The star will reappear after 90 minutes at 01:01 AM of June 16
Unlike a solar eclipse, which can only be viewed from a certain relatively small area of the world, a lunar eclipse may be viewed from anywhere on the night side of the Earth. A lunar eclipse lasts for a few hours, whereas a total solar eclipse lasts for only a few minutes at any given place. Some lunar eclipses have been associated with important historical events.
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| Lunar eclipse series sets from 1995-1998 |
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| This diagram shows how the moon appears reddish orange during a lunar eclipse. |
Types of lunar eclipse
The shadow of the Earth can be divided into two distinctive parts: the umbra and penumbra. Within the umbra, there is no direct solar radiation. However, as a result of the Sun’s large angular size, solar illumination is only partially blocked in the outer portion of the Earth’s shadow, which is given the name penumbra. A penumbral eclipse occurs when the Moon passes through the Earth’s penumbra. The penumbra causes a subtle darkening of the Moon's surface. A special type of penumbral eclipse is a total penumbral eclipse, during which the Moon lies exclusively within the Earth’s penumbra. Total penumbral eclipses are rare, and when these occur, that portion of the Moon which is closest to the umbra can appear somewhat darker than the rest of the Moon.
A partial lunar eclipse occurs when only a portion of the Moon enters the umbra. When the Moon travels completely into the Earth’s umbra, one observes a total lunar eclipse. The Moon’s speed through the shadow is about one kilometer per second (2,300 mph), and totality may last up to nearly 107 minutes. Nevertheless, the total time between the Moon’s first and last contact with the shadow is much longer, and could last up to 4 hours. The relative distance of the Moon from the Earth at the time of an eclipse can affect the eclipse’s duration. In particular, when the Moon is near its apogee, the farthest point from the Earth in its orbit, its orbital speed is the slowest. The diameter of the umbra does not decrease appreciably within the changes in the orbital distance of the moon. Thus, a totally eclipsed Moon occurring near apogee will lengthen the duration of totality.
The timing of total lunar eclipses are determined by its contacts:
P1 (First contact): Beginning of the penumbral eclipse. The Earth's penumbra makes contact with the outer limb of the Moon.
U1 (Second contact): Beginning of the partial eclipse. The Earth's umbra touches the outer limb of the Moon.
U2 (Third contact): Beginning of the total eclipse. The Moon is located completely within the Earth's umbra.
Greatest eclipse: The peak stage of the total eclipse. The Moon is at its closest to the center of the umbra.
U3 (Fourth contact): End of the total eclipse. The Moon's outer limb exits Earth's umbra.
U4 (Fifth contact): End of the partial eclipse. The Earth's umbra leaves the surface of the Moon.
P2 (Sixth contact): End of the penumbral eclipse. The Earth's shadow no longer makes any contact with the Moon.
A selenelion or selenehelion occurs when both the Sun and the eclipsed Moon can be observed at the same time. This can only happen just before sunset or just after sunrise, and both bodies will appear just above the horizon at nearly opposite points in the sky. This arrangement has led to the phenomenon being referred to as a horizontal eclipse. It happens during every lunar eclipse at all those places on the Earth where it is sunrise or sunset at the time. Indeed, the reddened light that reaches the Moon comes from all the simultaneous sunrises and sunsets on the Earth. Although the Moon is in the Earth’s geometrical shadow, the Sun and the eclipsed Moon can appear in the sky at the same time because the refraction of light through the Earth’s atmosphere causes objects near the horizon to appear higher in the sky than their true geometric position.
The Moon does not completely disappear as it passes through the umbra because of the refraction of sunlight by the Earth’s atmosphere into the shadow cone; if the Earth had no atmosphere, the Moon would be completely dark during an eclipse. The red coloring arises because sunlight reaching the Moon must pass through a long and dense layer of the Earth’s atmosphere, where it is scattered. Shorter wavelengths are more likely to be scattered by the air molecules and the small particles, and so by the time the light has passed through the atmosphere, the longer wavelengths dominate. This resulting light we perceive as red. This is the same effect that causes sunsets and sunrises to turn the sky a reddish color; an alternative way of considering the problem is to realize that, as viewed from the Moon, the Sun would appear to be setting (or rising) behind the Earth.
The amount of refracted light depends on the amount of dust or clouds in the atmosphere; this also controls how much light is scattered. In general, the dustier the atmosphere, the more that other wavelengths of light will be removed (compared to red light), leaving the resulting light a deeper red color. This causes the resulting coppery-red hue of the Moon to vary from one eclipse to the next. Volcanoes are notable for expelling large quantities of dust into the atmosphere, and a large eruption shortly before an eclipse can have a large effect on the resulting color.
thanks for reading hope u gained some what knowledge about lunar eclipse
