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Fun Friday: the Great Selenelion

Cisco Employee
Cisco Employee



Exactly 15 years ago, on July 28, 2008, the world witnessed a fascinating astronomical event known as the "Great Selenelion." During a lunar eclipse, which typically occurs when the Earth passes between the Sun and the Moon, a rare and incredible phenomenon happened.

In a regular lunar eclipse, the Earth's shadow falls on the Moon, gradually covering it until it turns a reddish hue due to the Earth's atmosphere bending sunlight and allowing only the longer-wavelength red light to reach the Moon.

However, during a Selenelion, the Sun and the eclipsed Moon can be seen simultaneously, even though they are usually on opposite horizons. This seemingly impossible sight happens because of atmospheric refraction, which causes the Sun and Moon to appear slightly above their actual positions for a brief moment.

This event is quite challenging to observe because it requires specific atmospheric conditions and precise timing. Selenelions can be rare and are a treat for sky gazers, as they provide a stunning and surreal view of both the Sun and the eclipsed Moon sharing the sky, even for a brief moment.

So, if you ever get the chance to witness a Selenelion, don't miss the opportunity to experience this extraordinary celestial spectacle!



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