Eclipses
Loading simulation…
flagWhat you'll discover
- arrow_forwardDescribe what happens during a solar eclipse
- arrow_forwardDescribe what happens during a lunar eclipse
- arrow_forwardExplain why eclipses don’t happen every month
- arrow_forwardKnow the safety rule: never look directly at the Sun
Solar eclipse: the Moon’s shadow
A solar eclipse happens when the Moon slides exactly between the Sun and Earth. The Moon’s shadow — a long dark cone — sweeps across part of Earth, and people standing inside it see the Sun covered up, sometimes completely.
By amazing coincidence, the Sun is about 400 times wider than the Moon but also about 400 times farther away, so they look the same size in our sky. That is why the Moon can cover the Sun so perfectly.
Lunar eclipse: Earth’s shadow
A lunar eclipse is the opposite line-up: Earth sits between the Sun and the Moon, and the Moon glides through Earth’s huge shadow cone.
Instead of going totally black, the eclipsed Moon usually glows a deep coppery red — sometimes called a "blood moon". Earth’s atmosphere bends a little red sunlight around the planet and into the shadow, like the light of every sunrise and sunset on Earth shining on the Moon at once.
Why not every month?
If the Moon orbited in exactly the same flat plane as Earth’s orbit, we would get a solar eclipse every New Moon and a lunar eclipse every Full Moon. But the Moon’s orbit is tilted by about 5 degrees.
Most months, the Moon passes a little above or below the perfect line, and its shadow misses Earth (or it misses Earth’s shadow). Try the tilt slider in the simulation: even a small tilt makes the shadows miss. Only when the line-up is perfect — a few times a year — do we get an eclipse somewhere on Earth.
Watch safely!
Never look directly at the Sun — during an eclipse or any other time. Even when 99% of the Sun is covered, the remaining sliver can permanently damage your eyes, and sunglasses are NOT enough protection.
Safe ways to enjoy a solar eclipse: certified eclipse glasses (ISO 12312-2), or a simple pinhole projector — poke a small hole in cardboard and project the Sun’s image onto the ground. Lunar eclipses, on the other hand, are completely safe to watch with bare eyes. Enjoy the red Moon!