why some observers of a solar eclipse see a total eclipse while others see only a partial eclipse?

Question

and why some observers from Earth see no eclipse at all?

Answer 1

An observer sees an eclipse of the sun when he is within the shadow of the moon as it races across the face of the earth. Since the moon is so much smaller than Earth, only a small portion of the Earth will experience the eclipse. The shadow is composed of two arts, the Umbra, in which the sun is entirely covered by the moon and the Penumbra, in which the moon only covers part of the sun. The Umbra almost looks like a focus of darkness when viewed from the side and covers a very small spot on earth and is the area within which a total eclipse is seen. Outside that area is the Penumbra, within which a viewer sees the partial eclipse. You can see a photograph of the Earth from space taken during a solar eclips from the Mir in 199 in the first source below and diagrams illustrating the Umbr and Penumbra in the second.

Answer 2

Eclipses, be they solar or lunar, occur when the Earth, Sun and Moon are in a line. If the Moon is in-between the Earth and the Sun, it blocks the view of the Sun from some parts of the Earth, and this produces a solar eclipse. If, on the contrary, it is the Earth that is in-between the Sun and Moon, then the earth will block the light from the Sun before it can get to the Moon. Since moonlight is just the light the Moon reflects from the Sun, this will darken the Moon, and we get a lunar eclipse.

Since the Moon goes around the Earth every 28 days, shouldn't we expect a solar eclipse about every 28 days (when the Moon is new), and a lunar one in the same period, (when the Moon is full) ?

Well, this would be so if the orbit of the Moon were in the same plane as the orbit of the Earth around the Sun. But we know eclipses are rarer than that; and the Moon's orbit is not in the same plane. Instead, it is tilted with respect to it, and the Moon does not in general pass directly on the Earth-Sun line. Moreover, the Moon's orbit tilt varies slowly. To have an eclipse, then, it is not enough that the three bodies be in the right order; the Moon's orbit should also be at the right tilt.
Whether it is the Moon between the Earth and Sun, or the other way around, the phenomenon is basically the same: the body in the middle casts a cone of shadow, and if the outer body happens to move into this cone, we have an eclipse. But the shadow is more complicated than just a cone: it actually consists of a darker cone, or umbra, where no sunlight reaches, and a lighter region, the penumbra, where only some of the sunlight is blocked. Whether you will be able to observe a total or partial eclipse will depend on which of the two regions you are located in.

Solar Eclipses
A solar eclipse occurs, as we said, when the Moon is directly between the Earth and the Sun. As noted above, these are not as frequent as one might expect, but there are still at least two each year. That we get total solar eclipses at all is a bit of good luck. The Moon and the Sun appear to have the same size when viewed from the Earth. The Moon is about 400 times smaller than the Sun, but at the same time the Sun is about 400 times farther away from the Earth than the Moon. Because of this, when there is a solar eclipse, the Moon is about the right size to completely cover the disk of the Sun. If the Moon is close enough to the Earth, it will cover it completely, and we get a total solar eclipse. This is the most spectacular kind, where the day changes into darkness, and one can see the stars in plain day. If the Moon is further away from the Earth, then its disk will not be big enough to cover the Sun completely, and we get an annular eclipse, where most of the sun is covered, but an annulus remains, surrounding the dark disk of the Moon.
Were the Moon to be smaller, or the Sun closer to the Earth, there would be no total solar eclipses. On the other hand, were the Moon a bit bigger, the shadow it casts on the Earth during solar eclipses would be larger, and it would be easier to be in the right place to observe them. The dark part of the Moon's shadow is, on the surface of the Earth, a circle of only about 160 miles in diameter. As the Earth moves, this circle traces a path on its surface, called the path of totality. To see a total solar eclipse you have to be inside this rather small region. It is estimated that, on the average, a given spot on the Earth will be on the path of an eclipse only about once every 370 years, so it is better to move to an eclipse than to wait for one to come to you.

Lunar Eclipses
As explained above, lunar eclipses do not occur every month because of the inclination of the Moon's orbit. They do happen at least twice a year, though. And you are far more likely to be able to observe one than a solar one. The reason is that when the Moon gets dark, it is because it does not receive the sunlight, and it then is dark for anyone who can see it. So, instead of having to be in a rather narrow path, as happens for solar eclipses, you only have to be in a part of the world from which the Moon is visible at the time of the eclipse. Pretty much half the world qualifies!

Answer 3

A solar eclipse is caused by the moon moving between the earth and sun, blocking its light. If you're in a position on earth directly in line with the sun and moon, you'll witness a total eclipse. However, if you're not quite in line (say the moon is directly over Africa and you're observing from Russia) the moon will only obscure a portion of the sun's rays, because some will slip past and reach your location. That is to say, the moon's shadow is not large enough to cover the whole earth. Parts of the earth will even remain entirely outside the shadow, and will not witness any eclipse. Even at the most favorable locations, a complete solar eclipse cannot last more than a few minutes.

Answer 4

Remember the moon is much smaller than the Earth. So, when it casts a shadow, the shadow forms a round shape of the same size almost on the surface of the earth. That is why some see a full eclipse, they are in the dot, and some see a partial, are on the edge of the dot, and some see nothing, are outside the dot of the shadow. The orbit of the moon is not in the same plane as the earth around the sun, which is why we do not see an eclipse every month. The moon has to be in the plane of the earth and sun in order to be between the earth and the sun and since the planes are different, only happens infrequently.

Answer 5

A solar eclipse is caused by the moon coming between the earth and sun. People in the area where the moons shadow is on the earth see the eclipse, those outside the shadow do not. If you are in the deepest part of the shadow, the umbra, where no sun light reaches you see a total eclipse, if your a little "off center" of the shadow your in the penumbra and see a partial eclipse.

Answer 6

An eclipse is a classic element that 2 diverse bodies circulate at an intersecting airplane. so we come across that that's volatile by way of fact we come across some unexpected exchange while the severe sunlight easy is long gone. while you at the instant are not conscious of the form it incredibly is probable which you will caught with some worry and which will impression the living beings. considering that birds at the instant are not conscious beforehand that an eclipse will ensue they get up set with the unexpected exchange of the situation. So additionally we are additionally probable to fulfill a similar emotions in a single of those situation. Our elders had made specific provisions for a similar and constrained the events to a pair quantity. Even to day with a good number of scientific awareness we are unsure touching directly to the reward or dis reward of the the eclipse. All are in perplexed state and why no longer be secure fairly than take any threat? The superstition do arise as and individuals work together and positioned across their stories with tat of a few subject. Why blame our elders for each element? Are we no longer arising superstitions ourselves? we could extra think of to distinguish proper from incorrect yet we don't opt to take that plenty difficulty ourselves and attempt to conceal at the back of superstitions whilst we condom a similar.

Answer 7

Some have their eyes wide open. Others half open. And some have them closed. Therefore, you see a full eclipse, half eclipse, or miss it altogether.

Just kidding. See Davencusa's answer. It is straight.

Answer 8

neat picture here.....

http://apod.nasa.gov/apod/ap990830.html

if you're not IN the shadow, you don't get a total eclipse, basically.... you'll only get a partial....and too far from it, you won't see anything special.....