In particular, when the Moon is near apogee, the farthest point from Earth in its orbit, its orbital speed is the slowest. The relative distance of the Moon from Earth at the time of an eclipse can affect the eclipse's duration. This type of lunar eclipse is relatively rare. This is a total lunar eclipse during which the Moon passes through the centre of Earth's shadow, contacting the antisolar point. It will be true of any planetary body with little or no atmosphere and an irregular cratered surface (e.g., Mercury) when viewed opposite the Sun. This is similar to the effect of velvet fabric over a convex curved surface which to an observer will appear darkest at the center of the curve. #SOLAR ECLIPSE MAESTRO LUNAR ECLIPSE FULL#This is because as viewed from the Earth, the brightness of a lunar limb is generally greater than that of the rest of the surface due to reflections from the many surface irregularities within the limb: sunlight striking these irregularities is always reflected back in greater quantities than that striking more central parts, and is why the edges of full moons generally appear brighter than the rest of the lunar surface. Later, as the Moon's opposite limb is struck by sunlight, the overall disk will again become obscured. The moment the Moon enters a complete eclipse, the entire surface will become more or less uniformly bright. Just prior to complete entry, the brightness of the lunar limb- the curved edge of the Moon still being hit by direct sunlight- will cause the rest of the Moon to appear comparatively dim. This occurs when the Moon falls entirely within the Earth's umbra. Nevertheless, the total time between the first and the last contacts of the Moon's limb with Earth's shadow is much longer and could last up to 236 minutes. The Moon's average orbital speed is about 1.03 km/s (2,300 mph), or a little more than its diameter per hour, so totality may last up to nearly 107 minutes. This occurs when only a portion of the Moon enters Earth's umbra, while a total lunar eclipse occurs when the entire Moon enters the planet's umbra. Total penumbral eclipses are rare, and when these occur, the portion of the Moon closest to the umbra may appear slightly darker than the rest of the lunar disk. A special type of penumbral eclipse is a total penumbral lunar eclipse, during which the Moon lies exclusively within Earth's penumbra. The penumbra causes a subtle dimming of the lunar surface, which is only visible to the naked eye when about 70% of the Moon's diameter has immersed into Earth's penumbra. This occurs when the Moon passes through Earth's penumbra. However, since the Sun's diameter appears about one-quarter of Earth's in the lunar sky, the planet only partially blocks direct sunlight within the penumbra, the outer portion of the shadow. Earth totally occludes direct solar radiation within the umbra, the central region of the shadow. This comparison of the Moon (within the southern part of Earth's shadow) during the penumbral lunar eclipse of January 1999 (left) and the Moon outside the shadow (right) shows this slight darkening.Įarth's shadow can be divided into two distinctive parts: the umbra and penumbra. The symbol for a lunar eclipse (or indeed any body in the shadow of another) is (U+1F776 □).įor the date of the next eclipse, see § Recent and forthcoming lunar eclipses.Ī total penumbral lunar eclipse dims the Moon in direct proportion to the area of the Sun's disk covered by Earth. Also unlike solar eclipses, lunar eclipses are safe to view without any eye protection or special precautions, as they are dimmer than a normal full Moon. A total lunar eclipse can last up to nearly 2 hours, while a total solar eclipse lasts only up to a few minutes at any given place, because the Moon's shadow is smaller. Unlike a solar eclipse, which can only be viewed from a relatively small area of the world, a lunar eclipse may be viewed from anywhere on the night side of Earth. This light appears reddish for the same reason that a sunset or sunrise does: the Rayleigh scattering of blue light. The reddish color of totally eclipsed Moon is caused by Earth completely blocking direct sunlight from reaching the Moon, with the only light reflected from the lunar surface has been refracted by Earth's atmosphere. The type and length of a lunar eclipse depend on the Moon's proximity to the lunar node. This can occur only when the Sun, Earth, and Moon are exactly or very closely aligned (in syzygy) with Earth between the other two, which can happen only on the night of a full moon when the Moon is near either lunar node. Latter phases of the partial lunar eclipse on 17 July 2019 taken from Gloucestershire, United KingdomĪ lunar eclipse occurs when the Moon moves into the Earth's shadow.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |