How do solar and lunar eclipses occur?
How do solar and lunar eclipses occur?
An overview of spatial relationships between the Sun, the Moon, and Earth during eclipses of the Sun and the Moon.
Encyclopædia Britannica, Inc.
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Encyclopædia Britannica, Inc.An overview of spatial relationships between the Sun, the Moon, and Earth during eclipses of the Sun and the Moon.
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Encyclopædia Britannica, Inc.It's a total eclipse of the Moon.
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Encyclopædia Britannica, Inc.Watch as a shadow slowly crosses the Earth.
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Encyclopædia Britannica, Inc.A solar eclipse is a celestial phenomenon occurring when the Moon appears to block out the Sun.
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NASAProminences are clouds of incandescent, ionized gas ejected from the Sun's surface. They are also some of the most dramatic phenomena in the solar system, the equivalent of thousand-mile-high storms that can rage for months. This time-lapse film shows active prominences of a few hours' duration. “Loop” prominences like this one, which seems to rise and fall back to the surface, are the aftermath of solar flares. Prominences are transparent in normal light and have to be viewed through special instruments that can detect the spectroscopic emission lines of hydrogen.
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Encyclopædia Britannica, Inc.The role of Earth's orbit and axis in determining its seasons.
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Encyclopædia Britannica, Inc.Learn about a total solar eclipse by observing it when it reaches totality.
Transcript
NARRATOR: Earth orbits the Sun while the Moon in turn orbits Earth. An eclipse occurs when all three bodies align.
While the Sun is 400 times larger than the Moon, it is also 400 times further away. This difference in perspective causes the two bodies to appear the same size. During a solar eclipse, the Moon passes between Earth and the Sun, blocking the Sun from viewers on Earth.
Whether viewers see a total or partial eclipse depends on where they are in relation to the Moon’s shadow.
The Moon casts two distinct regions of shadow on Earth during an eclipse: the inner core of dense shadow, called the umbra, and the surrounding region of partial shadow, called the penumbra.
When a viewer observes a solar eclipse from the penumbra, only a part of the Sun’s surface is obscured. This is a partial eclipse of the Sun.
For a viewer in the area covered by the umbra, the Sun is completely blocked out by the Moon. This is a total eclipse.
A lunar eclipse occurs when the Moon orbits through Earth’s shadow, preventing sunlight from illuminating it. It takes two hours for the Moon to pass through the shadow area, during which time it travels a distance of 5,000 miles.
While the Sun is 400 times larger than the Moon, it is also 400 times further away. This difference in perspective causes the two bodies to appear the same size. During a solar eclipse, the Moon passes between Earth and the Sun, blocking the Sun from viewers on Earth.
Whether viewers see a total or partial eclipse depends on where they are in relation to the Moon’s shadow.
The Moon casts two distinct regions of shadow on Earth during an eclipse: the inner core of dense shadow, called the umbra, and the surrounding region of partial shadow, called the penumbra.
When a viewer observes a solar eclipse from the penumbra, only a part of the Sun’s surface is obscured. This is a partial eclipse of the Sun.
For a viewer in the area covered by the umbra, the Sun is completely blocked out by the Moon. This is a total eclipse.
A lunar eclipse occurs when the Moon orbits through Earth’s shadow, preventing sunlight from illuminating it. It takes two hours for the Moon to pass through the shadow area, during which time it travels a distance of 5,000 miles.