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Lunar eclipse
A lunar eclipse, also called a blood moon, is an astronomical event that occurs when the Moon orbits through Earth's shadow. Lunar eclipses occur during eclipse season, when the Moon's orbital plane is approximately in line with Earth and the Sun. The type and length of a lunar eclipse depend on the Moon's proximity to the lunar node. In contrast with illusive and short-lasting solar eclipses, lunar eclipses can be observed from anywhere on the night side of Earth and often last for an hour or longer. Lunar eclipses are safe to observe without eye protection.
Lunar eclipses are notable for causing the Moon to appear orange or red. This occurs when the Moon passes through the Earth's umbra, necessitating any sunlight that reaches the Moon to first pass through the Earth's atmosphere. The resulting Rayleigh scattering removes high-wavelength colors such as violet and blue from the incoming light before it reflects off the lunar surface and is observed on Earth.
A penumbral lunar eclipse occurs when Earth's silhouette partially blocks the Sun in the lunar sky but does not occlude it completely, ensuring some sunlight can still reach the Moon directly. The designation refers to the Moon being partially inside of the penumbra, which describes the region of any shadow that is cast by a light source which is not collimated and has a non-zero angular diameter. A penumbral eclipse is designated as a total penumbral eclipse if the moon lies exclusively inside of the penumbra.
Penumbral eclipses are observed from Earth as a subtle dimming of the lunar surface. Of all lunar eclipses, approximately one-third are penumbral eclipses; of those, only 3% are total penumbral eclipses.
A partial lunar eclipse refers to the Moon lying partially inside of the umbra, where the relative size of the Earth in the lunar sky allows it to block the Sun entirely. During a partial eclipse, the dark region covered by the umbra will appear more much more distinct than the penumbral dimming.
The Moon's average orbital speed is about 1.03 km/s (2,300 mph), or a little more than its diameter per hour, so totality may last up to nearly 107 minutes. Nevertheless, the total time between the first and last contacts of the Moon's limb with Earth's shadow is much longer and could last up to 236 minutes.
When the Moon's near side entirely passes into the Earth's umbral shadow, a total lunar eclipse occurs. Just prior to complete entry, the brightness of the lunar limb—the curved edge of the Moon still being hit by direct sunlight—will cause the rest of the Moon to appear comparatively dim. The moment the Moon enters a complete eclipse, the entire surface will become more or less uniformly bright, being able to reveal stars surrounding it. Later, as the Moon's opposite limb is struck by sunlight, the overall disk will again become obscured.
This is because, as viewed from the Earth, the brightness of a lunar limb is generally greater than that of the rest of the surface, due to reflections from the many surface irregularities within the limb: sunlight striking these irregularities is always reflected back in greater quantities than that striking more central parts, which is why the edges of full moons generally appear brighter than the rest of the lunar surface. This is similar to the effect of velvet fabric over a convex curved surface, which, to an observer, will appear darkest at the center of the curve. It will be true of any planetary body with little or no atmosphere and an irregular cratered surface (e.g., Mercury) when viewed opposite the Sun.
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Lunar eclipse AI simulator
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Lunar eclipse
A lunar eclipse, also called a blood moon, is an astronomical event that occurs when the Moon orbits through Earth's shadow. Lunar eclipses occur during eclipse season, when the Moon's orbital plane is approximately in line with Earth and the Sun. The type and length of a lunar eclipse depend on the Moon's proximity to the lunar node. In contrast with illusive and short-lasting solar eclipses, lunar eclipses can be observed from anywhere on the night side of Earth and often last for an hour or longer. Lunar eclipses are safe to observe without eye protection.
Lunar eclipses are notable for causing the Moon to appear orange or red. This occurs when the Moon passes through the Earth's umbra, necessitating any sunlight that reaches the Moon to first pass through the Earth's atmosphere. The resulting Rayleigh scattering removes high-wavelength colors such as violet and blue from the incoming light before it reflects off the lunar surface and is observed on Earth.
A penumbral lunar eclipse occurs when Earth's silhouette partially blocks the Sun in the lunar sky but does not occlude it completely, ensuring some sunlight can still reach the Moon directly. The designation refers to the Moon being partially inside of the penumbra, which describes the region of any shadow that is cast by a light source which is not collimated and has a non-zero angular diameter. A penumbral eclipse is designated as a total penumbral eclipse if the moon lies exclusively inside of the penumbra.
Penumbral eclipses are observed from Earth as a subtle dimming of the lunar surface. Of all lunar eclipses, approximately one-third are penumbral eclipses; of those, only 3% are total penumbral eclipses.
A partial lunar eclipse refers to the Moon lying partially inside of the umbra, where the relative size of the Earth in the lunar sky allows it to block the Sun entirely. During a partial eclipse, the dark region covered by the umbra will appear more much more distinct than the penumbral dimming.
The Moon's average orbital speed is about 1.03 km/s (2,300 mph), or a little more than its diameter per hour, so totality may last up to nearly 107 minutes. Nevertheless, the total time between the first and last contacts of the Moon's limb with Earth's shadow is much longer and could last up to 236 minutes.
When the Moon's near side entirely passes into the Earth's umbral shadow, a total lunar eclipse occurs. Just prior to complete entry, the brightness of the lunar limb—the curved edge of the Moon still being hit by direct sunlight—will cause the rest of the Moon to appear comparatively dim. The moment the Moon enters a complete eclipse, the entire surface will become more or less uniformly bright, being able to reveal stars surrounding it. Later, as the Moon's opposite limb is struck by sunlight, the overall disk will again become obscured.
This is because, as viewed from the Earth, the brightness of a lunar limb is generally greater than that of the rest of the surface, due to reflections from the many surface irregularities within the limb: sunlight striking these irregularities is always reflected back in greater quantities than that striking more central parts, which is why the edges of full moons generally appear brighter than the rest of the lunar surface. This is similar to the effect of velvet fabric over a convex curved surface, which, to an observer, will appear darkest at the center of the curve. It will be true of any planetary body with little or no atmosphere and an irregular cratered surface (e.g., Mercury) when viewed opposite the Sun.