The umbra is the portion of a shadow from within which none of the light source is visible.
The penumbra is the portion of a shadow from within which part but not all of the light source is visible.
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"Umbra" is the area of total shadow, while "penumbra" is the area of partial shadow.
Since the sun is a big source of light and not just a single point, there are places
behind the Earth where the Earth blocks part of the sun from your view but not all
of it. If you're anywhere in that space, you can see part of the sun, but not all of
it. If that's where you are, then you're in the "penumbra" of the Earth's shadow.
If you're lined up right in the middle, and close enough to the back side of the
Earth, then it blocks the whole sun from your view and you can't see any of it.
Then you're in the "umbra" of the Earth's shadow.
First, the Sun is enormous - almost a million miles across. It is a lot closer to us than other stars. So, we see it as much more than just a point if light.
If the Sun appeared to us as just a point of light we would only experience the "umbra" and not the "penumbra" in eclipses.
The umbra is a "full" shadow. The penumbra is only a partial shadow, where some light gets through.
The Earth and Moon are much smaller than the Sun.
The full shadows of the Moon and the Earth are cone-shaped and come to a point.
Consider a solar eclipse. The full shadow caused by the Moon, where the entire Sun is blocked (and before the "point"), is the umbra.
The partial shadow, where only a portion of the Sun is blocked, or out beyond the point, is the penumbra.
(The Latin prefix "pen" means partial or almost, such as "penultimate" for the "almost ultimate", sometimes used in a sporting context to refer to the semi-final round.)
A Solar eclipse: an observer in the umbra of the Moon's shadow sees a total eclipse.
An observer in the penumbra of the Moon's shadow sees a partial eclipse.
A Lunar eclipse: In a total eclipse, the whole of Moon moves through the umbra
of the Earth's shadow.
In a partial eclipse, just a part of the Moon moves through the umbra of the Earth's shadow.
Note: If the Moon moves through only the penumbra of the Earth's shadow, that's a "penumbral eclipse". Such an eclipse is hardly noticeable.
It can be classed as a type of partial eclipse.
(The link below divides penumbral eclipses into two types.)
See "related link" below for more details, with diagrams.
Since the sun is a big source of light and not just a single point, there are places behind the Earth where the Earth blocks part of the sun from your view but not all of it. If you're anywhere in that space, you can see part of the sun, but not all of it. If that's where you are, then you're in the "penumbra" of the Earth's shadow.
If you're lined up right in the middle, and close enough to the back side of the
Earth, then it blocks the whole sun from your view and you can't see any of it.
Then you're in the "umbra" of the Earth's shadow.
The "umbra" is the complete shadow, while the prefix "pen" refers to something that is less than complete. So "penumbra" is the partial shadow.
You can do this as an experiment at home. Take three table lamps and line them up about two feet apart on one side of the room. Take a beach ball or a disk of cardboard (about a foot wide) to the other side of the room. There are three light sources. (In real life, the Sun is quite large, so three lamps gives us a good simulation.) Hold the beach ball or disk a couple of feet from the far wall. There will be an area of total shadow, where the direct rays of the lamps are blocked from all three lamps. This is the "umbra".
There will be a larger area of partial shadow, where the direct rays of one of the lamps can get to the wall, but the other two lamps are blocked; this is the "penumbra" or partial shadow.
If you move the disk away from the wall by a couple of feet, you'll get to a point where there is no umbra at all; the light from one lamp or the other reaches every part of the wall. That's the situation that we see in an annular eclipse, when the Moon is too far away to completely block the Sun's visible disk.
your shadow
Penumbra. Total shadow is the UMBRA. Partial shadow is the PENUMBRA. These words usually refer to solar/lunar eclipses. However, they can refer elsewhere to shadows.
an umbra is the center of the solar eclipse which is the darker part and the penumbra is farther away from the center of the eclipse and is brighter than the umbra
Umbra refers to the darkest part of a shadow where light is completely blocked by an object. Penumbra is the partial shadow region surrounding the umbra where some light is still able to reach. These terms are commonly used in astronomy and for understanding eclipses.
The umbra is the central, darkest part of a shadow during an eclipse where the light source is completely blocked. The penumbra is the lighter, outer part of the shadow where the light source is only partially blocked. During a solar eclipse, the umbra is responsible for causing total darkness in certain areas, while the penumbra results in a partial eclipse visible in surrounding regions.
The umbra is the darker total shadow; the penumbra is the surrounding partial shadow.
Shadows have two parts, the umbra and the penumbra. The umbra is the darker part of the shadow, in which all of the light from the source is blocked by the object casting the shadow. The penumbra, also known as the half-shadow, is the grayish part along the edge of a shadow in which only some of the light from the source is blocked.During a solar eclipse, if you are within the umbra of the moon's shadow, you are witnessing a total eclipse, and if you are within the penumbra of the moon's shadow, you are witnessing a partial eclipse.
your shadow
the umbra is a darker shadow than the penumbra
Penumbra. Total shadow is the UMBRA. Partial shadow is the PENUMBRA. These words usually refer to solar/lunar eclipses. However, they can refer elsewhere to shadows.
Its always two things that orbit and get in the way of the sun might think about umbra and penumbra
The umbra is associated with a total eclipse, penumbra with partial.
The umbra is the complete shadow; the penumbra is the partial shadow.Do this experiment. Place two lamps about 2 feet apart. Hold a basketball between the lamps and the wall. Each lamp throws its own shadow on the wall, but if you move the basketball close to the wall, there is a point where both shadows cross. The single shadow is the "penumbra". The combined shadows is the "umbra".
an umbra is the center of the solar eclipse which is the darker part and the penumbra is farther away from the center of the eclipse and is brighter than the umbra
umbra is the shadow and penumbra is the part the umbra is in
The word "umbra" comes from Latin, meaning "shadow." "Penumbra" is also from Latin, combining "paene," meaning "almost," with "umbra." "Antumbra" derives from Latin "anti," meaning "against," and "umbra."
Umbra refers to the darkest part of a shadow where light is completely blocked by an object. Penumbra is the partial shadow region surrounding the umbra where some light is still able to reach. These terms are commonly used in astronomy and for understanding eclipses.