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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 (see image above). 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 technically 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, the proper, but rarely used, term for what is commonly called a solar eclipse is eclipse of the Earth.

2007-01-02 01:15:59 · answer #1 · answered by black r 1 · 0 0

The plane of the ecliptic.
The path the Earth travels around the Sun and the path the moon travels are not on the same plane. It is only when these plane intercepts that we have an eclipse.
Imagine you have a dinner plate. If you draw a circle in the center for the sun and a circle on the rim for the Earth the plate will be the plane of the ecliptic. Now take a small side plate and draw a circle in the center for the Earth and a circle on the rim for the moon, that is the moons path around the Earth. If you had to let the two plates merge so the two dots that are Earth are in exactly the same spot but the plates are at a different angle you will notice that that there very few times the moon on edge of the small plate is directly between Earth and the sun. Keep in mind they are rotatin and the angle of the small plate changes to.
Hope this helps.

2007-01-02 03:44:01 · answer #2 · answered by PsiKnight9 3 · 0 0

It only happens when the moon is in direct alignment with the sun between the earth and the sun. The moon takes almost a month to reach the same point in alignment with the sun. However, the other factor is the tilt of the moon's orbit and whether your location is directly below the "shadow" of the moon. Because the moon doesn't revolve in a plane that is exactly aligned with the earth's revolution around the sun, it only crosses the plane at certain times.

2007-01-02 03:34:05 · answer #3 · answered by Puzzling 7 · 1 0

Size is a factor. Take a Hollywood movie premier spotlight (one that is at least 5 feet in diameter, you know a really ig one) and shine it at a say basketball or whatever approx oh 100 yards away. [No, these sizes and distances are NOT to scale; they're just me grabbing numbers to use as an example.] Now, take a baseball and wander in between the basketball and the spotlight about 8 yards away from the basketball.
Now, imagine the spotlight is the sun, the basketball is the earth and the baseball is the moon. You may cast a shadow on the basketball, but you will never obscure it. Now, move the three items in coordination with the real Sun, earth and Moon, and you'll see they don't always line up properly to put a shadow on the basketball.

2007-01-02 04:04:26 · answer #4 · answered by quntmphys238 6 · 0 0

Moon revolves around earth by chaging its angle @ 5 degrees(roughly) after every revolution. So Moon will not come in between earth and sun evertime it goes round the earth. Thats why solar eclipses wont happen everyday.

2007-01-02 03:36:20 · answer #5 · answered by stravis 2 · 1 0

Because the moon is our planet earth moon and it revolves around the earth at different times than what the earth revolves around the sun, therefore the times are totally different from each other.

2007-01-02 05:22:14 · answer #6 · answered by navysvn 1 · 0 0

we revolve around the sun the moon revolves around us in order for a solar eclispe the moon have to pass in front of the sun when we are directly in line with it so theres alot more to it than meets the eye

2007-01-02 04:30:51 · answer #7 · answered by Anonymous · 0 0

Because the moon doesn't constantly travel in a path that is in the same plane as our path around the sun, and it's not always between the Earth and the sun.

2007-01-02 03:32:54 · answer #8 · answered by magistra_linguae 6 · 0 0

They are your just not in the right place everyday.

2007-01-02 04:06:35 · answer #9 · answered by Mr Zip 2 · 0 1

we are revolving as well

2007-01-02 04:18:38 · answer #10 · answered by Anonymous · 0 0

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