The magnitude of eclipse is the fraction of the angular diameter of a celestial body being eclipsed. [1] This applies to all celestial eclipses. The magnitude of a partial or annular solar eclipse is always between 0.0 and 1.0, while the magnitude of a total solar eclipse is always greater than or equal to 1.0, and has a theoretically maximum value of around 1.12.
This measure is strictly a ratio of diameters and should not be confused with the covered fraction of the apparent area (disk) of the eclipsed body. Neither should it be confused with the astronomical magnitude scale of apparent brightness.
The apparent sizes of the Moon and Sun are both approximately 0.5°, or 30', but both vary because the distance between Earth and Moon varies. (The distance between Earth and Sun also varies, but the effect is slight in comparison.)
In an annular solar eclipse, the magnitude of the eclipse is the ratio between the apparent angular diameters of the Moon and that of the Sun during the maximum eclipse, yielding a ratio less than 1.0. As the magnitude of eclipse is less than one, the disk of the Moon cannot completely cover the Sun. When the centers of the two disks are sufficiently aligned, a ring of sunlight remains visible around the Moon. This is called an annular eclipse, from Latin annulus, meaning "ring". [2]
For a total solar eclipse to happen, the ratio of the apparent diameters of the Moon and of the Sun must be 1.0 or more, and the three celestial bodies (Sun, Earth and Moon) must be aligned centrally enough. When that is the case, the Moon's disk covers the Sun's disk in the sky completely. The path of totality (i.e. of the travelling shadow of the Moon cutting off all direct sunlight from reaching the Earth's surface) is a relatively narrow strip, at most a few hundreds of kilometers across.
In a partial solar eclipse, the magnitude of the eclipse is the fraction of the Sun's diameter occulted by the Moon at the time of maximum eclipse. As seen from one location, the momentary eclipse magnitude varies, being exactly 0.0 at the start of the eclipse, rising to some maximum value, and then decreasing to 0.0 at the end of the eclipse. When one says "the magnitude of the eclipse" without further specification, one usually means the maximum value of the magnitude of the eclipse.
The eclipse magnitude varies not only between eclipses, but also by viewing location. An eclipse may be annular in one location and total in another. These mixed-type eclipses are called hybrid. [2]
The effect on a lunar eclipse is quite similar, with a few differences. First, the eclipsed body is the Moon and the eclipsing 'body' is the Earth's shadow. Second, since the Earth's shadow at the Moon's distance always is considerably larger than the Moon, a lunar eclipse can never be annular but is always partial or total. Third, the Earth's shadow has two components: the dark umbra and the much brighter penumbra. A lunar eclipse will have two geometric magnitudes: the umbral magnitude and the penumbral magnitude. If the three bodies are not aligned enough, the Moon does not reach into the Earth's umbra - it may still pass through the Earth's penumbra though, and such an eclipse is called a penumbral eclipse.
An eclipse is an astronomical event that occurs when an astronomical object or spacecraft is temporarily obscured, by passing into the shadow of another body or by having another body pass between it and the viewer. This alignment of three celestial objects is known as a syzygy. An eclipse is the result of either an occultation or a transit. A "deep eclipse" is when a small astronomical object is behind a bigger one.
A lunar eclipse is an astronomical event that occurs when the Moon moves into the Earth's shadow, causing the Moon to be darkened. Such an alignment occurs during an eclipse season, approximately every six months, during the full moon phase, when the Moon's orbital plane is closest to the plane of the Earth's orbit.
Eclipses may occur repeatedly, separated by certain intervals of time: these intervals are called eclipse cycles. The series of eclipses separated by a repeat of one of these intervals is called an eclipse series.
The umbra, penumbra and antumbra are three distinct parts of a shadow, created by any light source after impinging on an opaque object. Assuming no diffraction, for a collimated beam of light, only the umbra is cast.
An annular solar eclipse occurred at the Moon's descending node of the orbit on October 3, 2005, with a magnitude of 0.958. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image of the Sun for a viewer on Earth. An annular solar eclipse occurs when the Moon's apparent diameter is smaller than the Sun's, blocking most of the Sun's light and causing the Sun to look like an annulus (ring). An annular eclipse appears as a partial eclipse over a region of the Earth thousands of kilometres wide. Occurring only 4.8 days after apogee, the Moon's apparent diameter was smaller. It was visible from a narrow corridor through the Iberian peninsula and Africa and Brazil. A partial eclipse was seen from the much broader path of the Moon's penumbra, including all of Europe, Africa and southwestern Asia. The Sun was 96% covered in a moderate annular eclipse, lasting 4 minutes and 32 seconds and covering a broad path up to 162 km wide. The next solar eclipse in Africa occurred just 6 months later.
A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby obscuring the view of the Sun from a small part of the Earth, totally or partially. Such an alignment occurs approximately every six months, during the eclipse season in its new moon phase, when the Moon's orbital plane is closest to the plane of the Earth's orbit. In a total eclipse, the disk of the Sun is fully obscured by the Moon. In partial and annular eclipses, only part of the Sun is obscured. Unlike a lunar eclipse, which may be viewed from anywhere on the night side of Earth, a solar eclipse can only be viewed from a relatively small area of the world. As such, although total solar eclipses occur somewhere on Earth every 18 months on average, they recur at any given place only once every 360 to 410 years.
A total lunar eclipse took place on 3 March 2007, the first of two eclipses in 2007. 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 with a distinctive brick-red shade. The Moon left the umbra shadow at 01:11 UTC and left the penumbra shadow at 02:24 UTC 2007-03-04. The second lunar eclipse of 2007 occurred on 28 August.
A total lunar eclipse occurred on February 20 and February 21, 2008. It was visible in the eastern evening sky on February 20 for all of North and South America, and on February 21 in the predawn western sky from most of Africa and Europe. Greatest Eclipse occurring on Thursday, February 21, 2008, at 03:26:03 UTC, totality lasting 49 minutes and 45.6 seconds.
A partial lunar eclipse took place on 7 September 2006, the second of two lunar eclipses in 2006. The tables below contain detailed predictions and additional information on the partial lunar eclipse of 7 September 2006.
A partial lunar eclipse took place on Saturday, June 25, 1983, the first of two lunar eclipses in 1983 with an umbral eclipse magnitude of 0.33479. A partial lunar eclipse happens when the Earth moves between the Sun and the Full Moon, but they are not precisely aligned. Only part of the Moon's visible surface moves into the dark part of the Earth's shadow. A partial lunar eclipse occurs when the Earth moves between the Sun and Moon but the three celestial bodies do not form a straight line in space. When that happens, a small part of the Moon's surface is covered by the darkest, central part of the Earth's shadow, called the umbra. The rest of the Moon is covered by the outer part of the Earth's shadow called the penumbra. The Earth's shadow on the moon was clearly visible in this eclipse, with 33% of the Moon in shadow; the partial eclipse lasted for 2 hours and 15 minutes.
A penumbral lunar eclipse took place on Tuesday, January 20, 1981, the first of two lunar eclipses in 1981. In a rare total penumbral eclipse, the entire Moon was partially shaded by the Earth, and the shading across the Moon should have been quite visible at maximum eclipse. The penumbral phase lasted for 4 hours and 24 minutes in all, though for most of it, the eclipse was extremely difficult or impossible to see. The moon's apparent diameter was larger because the eclipse occurred 5.2 days after perigee.
A partial lunar eclipse occurred on Tuesday, July 25, 1972 and Wednesday, July 26, 1972, the second of two lunar eclipses in 1972 with an umbral eclipse magnitude of 0.54271. A partial lunar eclipse occurs when the Earth moves between the Sun and Moon but the three celestial bodies do not form a straight line in space. When that happens, a small part of the Moon's surface is covered by the darkest, central part of the Earth's shadow, called the umbra. The rest of the Moon is covered by the outer part of the Earth's shadow called the penumbra. The moon's apparent diameter was 3.2 arcseconds smaller than the January 30, 1972 lunar eclipse.
A partial lunar eclipse took place on Saturday, July 6, 1963 with an umbral eclipse magnitude of 0.70602. The Moon was strikingly shadowed in this deep partial eclipse which lasted 3 hours exactly, with 71% of the Moon in darkness at maximum. A partial lunar eclipse occurs when the Earth moves between the Sun and Moon but the three celestial bodies do not form a straight line in space. When that happens, a small part of the Moon's surface is covered by the darkest, central part of the Earth's shadow, called the umbra. The rest of the Moon is covered by the outer part of the Earth's shadow called the penumbra. It was the second of three lunar eclipses in 1963, the first was a penumbral lunar eclipse on January 9, 1963 and the third and last was on December 30, 1963.
A partial lunar eclipse took place on Tuesday, November 29, 1955 with an umbral eclipse magnitude of 0.11899. A partial lunar eclipse happens when the Earth moves between the Sun and the Full Moon, but they are not precisely aligned. Only part of the Moon's visible surface moves into the dark part of the Earth's shadow. A partial lunar eclipse occurs when the Earth moves between the Sun and Moon but the three celestial bodies do not form a straight line in space. When that happens, a small part of the Moon's surface is covered by the darkest, central part of the Earth's shadow, called the umbra. The rest of the Moon is covered by the outer part of the Earth's shadow called the penumbra. It was the second of two lunar eclipses in 1955, first being the penumbral lunar eclipse on June 5. It also occurred near perigee, making such event a supermoon.
A penumbral lunar eclipse took place at the Moon's ascending of the orbit on Sunday, June 5, 1955, with a penumbral eclipse magnitude of 0.62181 (62.181%). A penumbral lunar eclipse takes place when the Moon moves through the faint, outer part of Earth's shadow, the penumbra. This type of eclipse is not as dramatic as other types of lunar eclipses and is often mistaken for a regular Full Moon. The Moon shines because its surface reflects the Sun's rays. A lunar eclipse happens when the Earth comes between the Sun and the Moon and blocks some or all of the Sun's light from reaching the Moon. A penumbral lunar eclipse occurs when the Sun, Earth, and the Moon are imperfectly aligned. When this happens, the Earth blocks some of the Sun's light from directly reaching the Moon's surface and covers all or part of the Moon with the outer part of its shadow, also known as the penumbra. Since the penumbra is much fainter than the dark core of the Earth's shadow, the umbra, a penumbral eclipse of the Moon is often difficult to tell apart from a normal Full Moon. Occurring only 0.5 days after apogee, the moon's apparent diameter was 6.5% smaller than average.
A total penumbral lunar eclipse is a lunar eclipse that occurs when the Moon becomes completely immersed in the penumbral cone of the Earth without touching the umbra.
Gamma of an eclipse describes how centrally the shadow of the Moon or Earth strikes the other body. This distance, measured at the moment when the axis of the shadow cone passes closest to the center of the Earth or Moon, is stated as a fraction of the equatorial radius of the Earth or Moon.
An annular solar eclipse will occur on October 2, 2024. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image of the Sun for a viewer on Earth. An annular solar eclipse occurs when the Moon's apparent diameter is smaller than the Sun's, blocking most of the Sun's light and causing the Sun to look like an annulus (ring). An annular eclipse appears as a partial eclipse over a region of the Earth thousands of kilometres wide.
An annular solar eclipse occurred on December 14, 1955. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image of the Sun for a viewer on Earth. An annular solar eclipse occurs when the Moon's apparent diameter is smaller than the Sun's, blocking most of the Sun's light and causing the Sun to look like an annulus (ring). An annular eclipse appears as a partial eclipse over a region of the Earth thousands of kilometres wide.
An annular solar eclipse will occur on Friday, November 4, 2078. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image of the Sun for a viewer on Earth. An annular solar eclipse occurs when the Moon's apparent diameter is smaller than the Sun's, blocking most of the Sun's light and causing the Sun to look like an annulus (ring). An annular eclipse appears as a partial eclipse over a region of the Earth thousands of kilometres wide. The path of annularity will cross Pacific Ocean, South America, and Atlantic Ocean. The tables below contain detailed predictions and additional information on the Annular Solar Eclipse of 4 November 2078.