The Moon's Glowing Tail
Like a comet, the Moon has a long tail streaming away from the Sun. Once a month, the Earth passes through it, and it can be seen as a faint spot in the sky.
What was reported
In 1998, after the Leonid meteor shower, astronomers at Boston University using sensitive cameras noticed a faint, glowing spot in the night sky, opposite the Sun. They found it was made by sodium atoms from the Moon, swept away by sunlight into a long tail stretching far beyond the Earth.
Every month, around new Moon, the Earth passes through the tail, and Earth's gravity focuses it into a spot in the sky, several times wider than the full Moon, too faint to see without special cameras.
Explanations offered
Meteoroids constantly hit the Moon's surface, knocking off sodium atoms into its very thin atmosphere. Sunlight pushes them away, forming a tail that glows orange in the light. It brightens after major meteor showers. Mercury has a similar tail.
- When
- Discovered in 1998
- Where
- The Moon
- Witnesses
- Astronomers using sensitive cameras
- Status
- Confirmed
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