Speed of Light

The maximum velocity for everything in the universe; 186,282.397 miles (299,792.458 km) per second, or fast enough to go to the Moon and back in less than three seconds.

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More Moon and Companions Turning on some far-away lamps Wednesday, June 27, 2012

More Moon and Jupiter Charting the limited speed of light Wednesday, October 20, 2010

Distant Dubhe

Today on StarDate

A black hole devours a companion

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