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.

Radio Programs

Night Watch Picturing the distant stars April 3, 2016

Moon and Spica The end of a long journey February 26, 2016

More Moon and Companions Turning on some far-away lamps June 26, 2012

Today on StarDate

A big astronomical dwarf

+
Get the ultimate StarDate fan experience with our premium digital package — a one-year subscription to the digital edition of StarDate magazine and a one-year subscription to our same-day audio service. Get both together for just $45, a savings of 20% over purchasing both separately.

Order Now

Astronomy Gifts

Logo Hooded Sweatshirt

$34.95

Make a Contribution

StarDate depends on the support of listeners and astronomy enthusiasts like you. Please consider making a tax-deductible contribution to StarDate.

Support StarDate

Main menu

You are here

Speed of Light

Radio Programs