A 'solar eclipse' occurs when the
Moon passes between
Earth and the
Sun, thereby totally or partially obscuring Earth's view of the Sun. This configuration can only occur during a
new moon, when the Sun and Moon are in
conjunction as seen from the Earth.
In ancient times, and in some cultures today, solar eclipses are attributed to mythical properties. Total solar eclipses can be frightening events for people unaware of their astronomical nature, as the Sun suddenly disappears in the middle of the day and the sky darkens in a matter of minutes. However, the spiritual attribution of solar eclipses is now largely disregarded.
Total solar eclipses are very rare events for any given place on Earth because totality is only seen where the Moon's
umbra touches the Earth's surface. A total solar eclipse is a spectacular
natural phenomenon and many people consider travel to remote locations in order to observe one.
The
1999 total eclipse in
Europe, said by some to be the most-watched eclipse in human history, helped to increase public awareness of the phenomenon. This was illustrated by the number of people willing to make the trip to witness the
2005 annular eclipse and the
2006 total eclipse. The next solar eclipse takes place on
September 11,
2007, while the next total solar eclipse will occur on
August 1, 2008.
Types
Annular eclipse.
There are four types of solar eclipses:
★ A ''total eclipse'' occurs when the Sun is completely obscured by the Moon. The intensely bright disk of the Sun is replaced by the dark outline of the Moon, and the much fainter
corona is visible. During any one eclipse, totality is visible only from at most a narrow track on the surface of the Earth.
★ An ''annular eclipse'' occurs when the Sun and Moon are exactly in line, but the apparent size of the Moon is smaller than that of the Sun. Hence the Sun appears as a very bright ring, or
annulus, surrounding the outline of the Moon.
★ A ''hybrid eclipse'' is intermediate between a total and annular eclipse. At some points on the surface of the Earth it is visible as a total eclipse, whereas at others it is annular. Hybrid eclipses are rather rare.
★ A ''partial eclipse'' occurs when the Sun and Moon are not exactly in line, and the Moon only partially obscures the Sun. This phenomenon can usually be seen from a large part of the Earth outside of the track of an annular or total eclipse. However, some eclipses can only be seen as a partial eclipse, because the umbra never intersects the Earth's surface.
The Earth's distance from the Sun is about 400 times the Moon's distance from the Earth. The Sun's
diameter is about 400 times the diameter of the Moon. Because these ratios are approximately the same, the sizes of the Sun and the Moon as seen from Earth appear to be approximately the same: about 0.5
degree of arc in angular measure.
Because the Moon's orbit around the Earth is an
ellipse, as is the Earth's orbit around the Sun, the apparent sizes of the Sun and Moon vary.
[1][2] The
magnitude of an eclipse is the ratio of the apparent size of the Moon to the apparent size of the Sun during an eclipse. An eclipse when the Moon is near its closest distance from the Earth (i.e., near its
perigee) can be a total eclipse because the Moon will appear to be large enough to cover completely the Sun's bright disk, or
photosphere; a total eclipse has a magnitude greater than 1. Conversely, an eclipse when the Moon is near its farthest distance from the Earth (i.e., near its
apogee) can only be an annular eclipse because the Moon will appear to be slightly smaller than the Sun; the magnitude of an annular eclipse is less than 1. Slightly more solar eclipses are annular than total because, on average, the Moon lies too far from Earth to cover the Sun completely. A hybrid eclipse occurs when the magnitude of an eclipse is very close to 1: the eclipse will appear to be total at some locations on Earth and annular at other locations.
[3]
The Earth's orbit around the Sun is also elliptical, so the Earth's distance from the Sun varies throughout the year. This also affects the apparent sizes of the Sun and Moon, but not so much as the Moon's varying distance from the Earth. When the Earth approaches its farthest distance from the Sun (the
aphelion) in July, this tends to favor a total eclipse. As the Earth approaches its closest distance from the Sun (the
perihelion) in January, this tends to favor an annular eclipse.
Terminology
''Central eclipse'' is often used as a generic term for a total, annular, or hybrid eclipse. This is, however, not completely correct: the definition of a central eclipse is an eclipse during which the central line of the umbra touches the Earth's surface. It is possible, though extremely rare, that part of the umbra intersects with Earth (thus creating an annular or total eclipse), but not its central line. This is then called a non-central total or annular eclipse.
[4]
The term ''solar eclipse'' itself is strictly speaking a misnomer. The phenomenon of the Moon passing in front of the Sun is not an eclipse, but an
occultation. Properly speaking, an eclipse occurs when one object passes into the shadow cast by another object. For example, when the Moon disappears at
full moon by passing into Earth's shadow, the event is properly called a ''
lunar eclipse''. Therefore, technically, a ''solar eclipse'' actually amounts to an eclipse of the Earth.
Predictions
Geometry
Diagram of solar eclipse (not to scale).
The diagram to the right shows the alignment of the Sun, Moon and Earth during a solar eclipse. The dark gray region below the Moon is the
umbra, where the Sun is completely obscured by the Moon. The small area where the umbra touches the Earth's surface is where a total eclipse can be seen. The larger light gray area is the
penumbra, in which only a partial eclipse can be seen.
The
Moon's orbit around the Earth is inclined at an angle of just over 5 degrees to the plane of the Earth's orbit around the Sun (the
ecliptic). Because of this, at the time of a new moon, the Moon will usually pass above or below the Sun. A solar eclipse can occur only when the new moon occurs close to one of the points (known as
nodes) where the Moon's orbit crosses the ecliptic.
As noted above, the Moon's orbit is also
elliptical. The Moon's distance from the Earth can vary by about 6% from its average value. Therefore, the Moon's apparent size varies with its distance from the Earth, and it is this effect that leads to the difference between total and annular eclipses. The distance of the Earth from the Sun also varies during the year, but this is a smaller effect. On average, the Moon appears to be slightly smaller than the Sun, so the majority (about 60%) of central eclipses are annular. It is only when the Moon is closer to the Earth than average (near its
perigee) that a total eclipse occurs.
[5][6]
The Moon orbits the Earth in approximately 27.3 days, relative to a fixed frame of reference. This is known as the
sidereal month. However, during one sidereal month, the Earth has revolved part way around the Sun, making the average time between one new moon and the next longer than the sidereal month: it is approximately 29.5 days. This is known as the
synodic month, and corresponds to what is commonly called the
lunar month.
'A' Total eclipse in the umbra.
'B' Annular eclipse in the antumbra.
'C' Partial eclipse in the penumbra
The Moon crosses from south to north of the ecliptic at its
ascending node, and vice versa at its descending node. However, the nodes of the Moon's orbit are gradually moving in a
retrograde motion, due to the action of the Sun's gravity on the Moon's motion, and they make a complete circuit every 18.6 years. This means that the time between each passage of the Moon through the ascending node is slightly shorter than the sidereal month. This period is called the
draconic month.
Finally, the Moon's perigee is moving forwards in its orbit, and makes a complete circuit in about 9 years. The time between one perigee and the next is known as the
anomalistic month.
The Moon's orbit intersects with the ecliptic at the two nodes that are 180 degrees apart. Therefore, the new moon occurs close to the nodes at two periods of the year approximately six months apart, and there will always be at least one solar eclipse during these periods. Sometimes the new moon occurs close enough to a node during two consecutive months. This means that in any given year, there will always be at least two solar eclipses, and there can be as many as five. However, some are visible only as partial eclipses, because the umbra passes above Earth's north or south pole, and others are central only in remote regions of the
Arctic or
Antarctic.
[7][8]
Path
During a central eclipse, the Moon's umbra (or
antumbra, in the case of an annular eclipse) moves rapidly from west to east across the Earth. The Earth is also rotating from west to east, but the umbra always moves faster than any given point on the Earth's surface, so it almost always appears to move in a roughly west-east direction across a map of the Earth (there are some rare exceptions to this which can occur during an eclipse of the
midnight sun in Arctic or Antarctic regions).
The width of the track of a central eclipse varies according to the relative apparent diameters of the Sun and Moon. In the most favourable circumstances, when a total eclipse occurs very close to perigee, the track can be over 250 km wide and the duration of totality may be over 7 minutes. Outside of the central track, a partial eclipse can usually be seen over a much larger area of the Earth.
[9]
Occurrence and cycles
Total Solar Eclipse Paths: 1001–2000. This image was merged from 50 separate images from NASA.
[10]
Total solar eclipses are rare events. Although they occur somewhere on Earth approximately every 18 months, it has been estimated that they recur at any given place only once every 370 years, on average. The total eclipse only lasts for a few minutes at that location, as the Moon's umbra moves eastward at over 1700 km/h. Totality can never last more than 7 min 40 s, and is usually much shorter: during each
millennium there are typically fewer than 10 total solar eclipses exceeding 7 minutes. The last time this happened was
June 30 1973. Observers aboard a
Concorde aircraft were able to stretch totality to about 74 minutes by flying along the path of the Moon's umbra. The next eclipse of comparable duration will not occur until
June 25,
2150. The longest total solar eclipse during the 8,000-year period from 3000 BC to 5000 AD will occur on
July 16 2186, when totality will last 7 min 29 s.
[11]
If the date and time of any solar eclipse are known, it is possible to predict other eclipses using
eclipse cycles. Two such cycles are the
Saros and the
Inex. The Saros cycle is probably the best known, and one of the most accurate, eclipse cycles. The Inex cycle is itself a poor cycle, but it is very convenient in the classification of eclipse cycles. After a Saros cycle finishes, a new Saros cycle begins one Inex later, hence its name: in-ex. A Saros cycle lasts 6,585.3 days (a little over 18 years), which means that after this period a practically identical eclipse will occur. The most notable difference will be a shift of 120° in longitude (due to the 0.3 days) and a little in latitude. A Saros series always starts with a partial eclipse near one of Earth's polar regions, then shifts over the globe through a series of annular or total eclipses, and ends at the opposite polar region. A Saros lasts 1226 to 1550 years and 69 to 87 eclipses, with about 40 to 60 central.
[12]
Final totality
Due to
tidal acceleration, the orbit of the Moon around the Earth becomes approximately 3.8 cm more distant each year. It is estimated that in 600 million years, the distance from the Earth to the Moon will have increased by 23,500 km, meaning that it will no longer be able to completely cover the Sun's disk. This will be true even when the Moon is at
perigee, and the Earth at
aphelion.
A complicating factor is that the Sun will increase in size over this timescale. This makes it even more unlikely that the Moon will be able to cause a total eclipse. We can therefore say that the last total solar eclipse on Earth will occur in slightly less than 600 million years.
[13]
Historical eclipses
A solar eclipse of
June 15 763 BC mentioned in an
Assyrian text is important for the
Chronology of the Ancient Orient. Also known as the
eclipse of Bur Sagale, it is the earliest solar eclipse mentioned in historical sources that has been successfully identified. Perhaps the earliest still-unproven claim is that of archaeologist Bruce Masse; on the basis of several ancient
flood myths that mention a total solar eclipse, he links an eclipse that occurred
May 10 2807 BC with a possible
meteor impact in the
Indian Ocean.
[14] There have been other claims to date earlier eclipses, notably that of
Mursili II (likely 1312 BC), in
Babylonia, and also in China, during the 5th year (2084 BC) of the regime of king
Zhong Kang of Xia dynasty, but these are highly disputed and rely on much supposition.
[15][11]
Herodotus wrote that
Thales of Miletus predicted an eclipse which occurred during a war between the
Medians and the
Lydians. Soldiers on both sides put down their weapons and declared peace as a result of the eclipse. Exactly which eclipse was involved has remained uncertain, although the issue has been studied by hundreds of ancient and modern authorities. One likely candidate took place on
May 28585 BC, probably near the
Halys river in the middle of modern
Turkey.
[17]
An annular eclipse of the Sun occurred at
Sardis on
February 17 478 BC, while
Xerxes was departing for his expedition against
Greece, as Herodotus recorded.
[18] Hind and Chambers considered this absolute date more than a century ago.
[19] Herodotus also reports that another solar eclipse was observed in
Sparta during the next year, on
August 1 477 BC.
[20][21][20] The sky suddenly darkened in the middle of the day, well after the battles of
Thermopylae and
Salamis, after the departure of
Mardonius to
Thessaly at the beginning of the spring of (477 BC) and his second attack on
Athens, after the return of
Cleombrotus to
Sparta. Note that the modern conventional dates are different by a year or two, and that these two eclipse records have been ignored so far.
[23] The Chronicle of Ireland recorded a solar eclipse on
June 29,
512 AD, and a solar eclipse was reported to have taken place during the
Battle of Stiklestad in the summer of 1030.
It has also been attempted to establish the exact date of
Good Friday by means of solar eclipses, but this research has not yielded conclusive results.
[24] Research has manifested the inability of total solar eclipses to serve as explanations for the recorded
Good Friday features of the
crucifixion eclipse.
[25]
The
ancient Chinese astronomer
Shi Shen (fl. 4th century BC) was aware of the relation of the moon in a solar eclipse, as he provided instructions in his writing to predict them by using the relative positions of the moon and sun.
[26] The 'radiating influence' theory for a solar eclipse (i.e., the moon's light was merely light reflected from the sun) was existent in Chinese thought from about the 6th century BC (in the ''Zhi Ran'' of Zhi Ni Zi),
and opposed by the
Chinese philosopher Wang Chong (
27–
97 AD), who made clear in his writing that this theory was nothing new.
[27] This can be said of Jing Fang's writing in the 1st century BC, which stated:
The ancient Greeks had known this as well, since it was
Parmenides of
Elea around 475 BC who supported the theory of the moon shining because of reflected light, and was accepted in the time of
Aristotle as well.
The Chinese astronomer and inventor
Zhang Heng (
78–
139 AD) wrote of both solar and lunar eclipses in the publication of ''Ling Xian'' in 120 AD, supporting the radiating influence theory that Wang Chong had opposed (
Wade-Giles):
The later Chinese scientist and statesman
Shen Kuo (
1031–
1035 AD) also wrote of eclipses, and his reasoning for why the celestial bodies were round and spherical instead of flat (
Wade-Giles spelling):
Viewing
Looking directly at the
photosphere of the Sun (the bright disk of the Sun itself), even for just a few seconds, can cause permanent damage to the
retina of the eye, because of the intense visible and invisible radiation that the photosphere emits. This damage can result in permanent impairment of vision, up to and including
blindness. The retina has no sensitivity to pain, and the effects of retinal damage may not appear for hours, so there is no warning that injury is occurring.
[28]
Under normal conditions, the Sun is so bright that it is difficult to stare at it directly, so there is no tendency to look at it in a way that might damage the eye. However, during an eclipse, with so much of the Sun covered, it is easier and more tempting to stare at it. Unfortunately, looking at the Sun during an eclipse is just as dangerous as looking at it outside an eclipse, except during the brief period of totality, when the Sun's disk is completely covered (totality occurs only during a total eclipse and only very briefly; it does not occur during a partial or annular eclipse). Viewing the Sun's disk through any kind of optical aid (binoculars, a telescope, or even an optical camera viewfinder) is even more hazardous.
[29]
Glancing at the Sun with all or most of its disk visible is unlikely to result in permanent harm, as the pupil will close down and reduce the brightness of the whole scene. If the eclipse is near total, the low average amount of light causes the pupil to open. Unfortunately the remaining parts of the Sun are still just as bright, so they are now brighter on the retina than when looking at a full Sun. As the eye has a small
fovea, for detailed viewing, the tendency will be to track the image on to this best part of the retina, causing damage.
Partial and annular eclipses
Eclipse glasses.
Viewing the Sun during partial and annular eclipses (and during total eclipses outside the brief period of totality) requires special eye protection, or indirect viewing methods. The Sun's disk can be viewed using appropriate filtration to block the harmful part of the Sun's radiation. Sunglasses are not safe, since they do not block the harmful and invisible
infrared radiation which causes retinal damage. Only properly designed and certified solar filters should ever be used for direct viewing of the Sun's disk.
[30]
The safest way to view the Sun's disk is by indirect projection. This can be done by projecting an image of the disk onto a white piece of paper or card using a pair of binoculars (with one of the lenses covered), a telescope, or another piece of cardboard with a small hole in it (about 1 mm diameter), often called a
pinhole camera. The projected image of the Sun can then be safely viewed; this technique can be used to observe
sunspots, as well as eclipses. However, care must be taken to ensure that no one looks through the projector (telescope, pinhole, etc.) directly. Viewing the Sun's disk on a video display screen (provided by a
video camera or
digital camera) is safe, although the camera itself may be damaged by direct exposure to the Sun. The optical viewfinders provided with some video and digital cameras are not safe.
In the partial eclipse path one will not be able to see the spectacular corona or nearly complete darkening of the sky, yet, depending on how much of the sun's disk is obscured, some darkening may be noticeable. If two-thirds or more of the sun is obscured, then an effect can be observed by which the daylight appears to be dim, as if the sky were overcast, yet objects still cast sharp shadows.
Totality
Contrary to popular belief, it is safe to observe the total phase of a solar eclipse directly with the unaided eye, binoculars or a telescope, when the Sun's photosphere is 'completely' covered by the Moon; indeed, this is a very spectacular and beautiful sight, and it is too dim to be seen through filters. The Sun's faint
corona will be visible, and even the
chromosphere,
solar prominences, and possibly even a
solar flare may be seen. However, it is important to stop directly viewing the Sun promptly at the end of totality. The exact time and duration of totality for the location from which the eclipse is being observed should be determined from a reliable source.
Baily's beads.
Also very beautiful are the effects just before (and just after) totality. When the shrinking visible part of the photosphere becomes very small,
Baily's beads will occur (see picture). These are caused by the sunlight still being able to reach Earth through lunar valleys, but no longer where mountains are present. Totality then begins with the diamond ring effect, the last bright flash of sunlight.
[31] Note that it is not entirely safe to view Baily beads or the diamond ring without proper eye protection (because in both cases the photosphere is still visible).
Other observations
For
astronomers, a total solar eclipse forms a rare opportunity to observe the
corona (the outer layer of the Sun's atmosphere). Normally this is not visible because the
photosphere is much brighter than the corona. According to the point reached in the
solar cycle, the corona can appear rather small and symmetric, or large and fuzzy. It is very hard to predict this prior to totality.
[32]
During a solar eclipse, special (indirect) observations can also be done with the unaided eye only. Normally the spots of light which fall through the small openings between the leaves of a tree, have a circular shape. These are images of the Sun. During a partial eclipse, the light spots will show the partial shape of the Sun, as seen on the picture. Another famous phenomenon is shadow bands (also known as flying shadows), which are similar to shadows on the bottom of a swimming pool. They only occur just prior to and after totality, and are very difficult to observe. Many professional eclipse chasers have never seen them.
[33]
During a partial eclipse, a related effect that can be seen is anisotropy in the shadows of objects. Particularly if the partial eclipse is nearly total, the unobscured part of the sun acts as an approximate line source of light. This means that objects cast shadows which have a very narrow penumbra in one direction, but a broad penumbra in the perpendicular direction.
1919 observations
In
1919, the observation of a total solar eclipse helped to confirm
Einstein's theory of
general relativity. By comparing the apparent distance between two stars, with and without the Sun between them,
Arthur Eddington stated that the
theoretical predictions about
gravitational lenses were confirmed, though it now appears the data were ambiguous at the time. The observation with the Sun between the stars was only possible during totality, since the stars are then visible.
[34]
Before sunrise, after sunset
The phenomenon of
atmospheric refraction makes it possible to observe the Sun (and hence a solar eclipse) even when it is slightly below the horizon. It is however possible for a solar eclipse to attain totality (or in the event of a partial eclipse, near-totality) before (visual and actual) sunrise or after sunset from a particular location. When this occurs shortly before the former or after the latter, the sky will appear much darker than it would otherwise be immediately before sunrise or after sunset. On these occasions, an object (especially a
planet, often
Mercury) may be visible near the sunrise or sunset point of the horizon when it could not have been seen without the eclipse.
[35]
Eclipses and transits
In principle, the simultaneous occurrence of a Solar eclipse and a transit of a planet is possible. But these events are extremely rare because of their short durations. The next anticipated simultaneous occurrence of a Solar eclipse and a
transit of Mercury will be on
July 5,
6757, and a Solar eclipse and a
transit of Venus is expected on
April 5,
15232.
[36]
Only 5 hours after the transit of Venus on
June 4,
1769, there was a total solar eclipse, which was visible in Northern America, Europe and Northern Asia as partial solar eclipse. This was the lowest time difference between a transit of a planet and a solar eclipse in the historical past.
More common, but still quite rare, is a
conjunction of any planet (not confined exclusively to Mercury or Venus) at the time of a total solar eclipse, in which event the planet will be visible very near the eclipsed Sun, when without the eclipse it would have been lost in the Sun's glare. At one time, some scientists hypothesized that there may be a planet (often given the name
Vulcan) even closer to the Sun than Mercury; the only way to confirm its existence would have been to observe it during a total solar eclipse. However, it is now known that no such planet exists. While there does remain some possibility for small
Vulcanoid asteroids to exist, none have ever been found.
Artificial satellites
Shadow of the moon, seen from the ISS in
2006.
Artificial satellites can also pass in front of, or ''transit'', the Sun as seen from Earth, but none are large enough to cause an eclipse. At the altitude of the
International Space Station, for example, an object would need to be about 3.35 km across to blot the Sun out entirely. These transits are difficult to watch, because the zone of visibility is very small. The satellite passes over the face of the Sun in about a second, typically. As with a transit of a planet, it will not get dark.
[37]
Artificial satellites do play an important role in documenting solar eclipses. Images of the umbra on the Earth's surface taken from
Mir and the
International Space Station are among the most spectacular eclipse images in history.
[38] Observations of eclipses from satellites orbiting above the Earth's atmosphere are of course not subject to weather conditions.
The direct observation of a total solar eclipse from space is rather rare. The only documented case is
Gemini 12 in
1966. The partial phase of the
2006 total eclipse was visible from the
International Space Station. At first, it looked as though an orbit correction in the middle of March would bring the ISS in the path of totality, but this correction was postponed.
[39]
See also
Eclipses elsewhere
★
Solar eclipses on Jupiter
★
Solar eclipses on Pluto
★
Transit of Phobos from Mars
★
Transit of Deimos from Mars
Eclipse lists
★
★
List of solar eclipses
★
List of solar eclipses seen from China
★
List of solar eclipses visible from the United Kingdom 1000 - 2090 AD
Miscellaneous
★
Allais effect
★
Crucifixion eclipse
★
Solar eclipses in fiction
Notes
1. Solar Eclipses
2. Types of Solar Eclipse P. Tiedt
3. Solar Eclipses for Beginners O. Staiger
4. Central Solar Eclipses F. Espenak
5. Why Eclipses Happen R. Hipschman
6. What Causes an Eclipse?
7. Fifty Year Canon of Solar Eclipses: 1986–2035, F. Espenak, , , NASA RP-1178, ,
8. Canon of Solar Eclipses, J. Meeus, C. Grosjean, W. and Vanderleen, , , Pergamon Press, ,
9. Eclipse
10. World Atlas of Solar Eclipse Paths F. Espenak
11. Historical Eclipses and Earth's Rotation, F.R. Stephenson, , , Cambridge University Press, ,
12. Eclipses and the Saros F. Espenak
13. The Final Total Eclipse A. Kendall
14. Ancient Crash, Epic Wave Sandra Blakeslee
15. Solar Eclipses of Historical Interest F. Espenak
16. Historical Eclipses and Earth's Rotation, F.R. Stephenson, , , Cambridge University Press, ,
17. Eclipse Quotations D. Le Conte
18. Book VII, Herodotus, , , , ,
19. untitled, Hind and Chambers, , , , ,
20. Book IX, Herodotus, , , , ,
21. Book VIII, Herodotus, , , , ,
22. Book IX, Herodotus, , , , ,
23. Solar Eclipses That Changed the World, B. E. Schaefer, , , Sky and Telescope, ,
24. Dating the Crucifixion, C. J. Humphreys and W. G. Waddington, , , Nature, Vol. 306, No. 5945, ,
25. M. Kidger (1999). ''The Star of Bethlehem: An Astronomer’s View''. Princeton, N. J: Princeton University Press, 68–72.
26. Needham, Volume 3, 411.
27. Needham, Volume 3, 411–413.
28. Eye Safety During Solar Eclipses F. Espenak
29. How to Watch a Partial Solar Eclipse Safely A. M. MacRobert
30. Observing Eclipses Safely O. Staiger
31. The Experience of Totality O. Staiger
32. The science of eclipses
33. Flying Shadows D. Dravins
34. Relativity and the 1919 eclipse
35. Musings About Twilight D. Criner
36. Simultaneous transits J. Meeus and A. Vitagliano
37. ISS-Venustransit
38. Looking Back on an Eclipsed Earth
39. JSC Digital Image Collection
References
★ Needham, Joseph (1986). ''Science and Civilization in China: Volume 3''. Taipei: Caves Books, Ltd.
External links
General
★
NASA's Eclipse Home Page,
Fred Espenak
★
Solar Eclipse Resources
★
Detailed eclipse explanations and predictions, Hermit Eclipse
★
Prof. Druckmüller's eclipse photography site
★
World Atlas of Solar Eclipse Paths, F. Espenak
★
Animated maps of present and past eclipses all over the world (ShadowandSubstance.com)
★
NightSkyInfo.com: All About Solar Eclipses
Eye safety
★
Eye Safety During Solar Eclipses, F. Espenak (NASA Goddard Space Flight Center)
★
How to Watch a Partial Solar Eclipse Safely, A. M. MacRobert (Sky & Telescope magazine)
★
UK hospitals assess eye damage after solar eclipse, British Medical Journal,
August 21 1999, p. 319–469
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