If astronomers at the star Regulus could pick up radio broadcasts from Earth, right about now they’d be hearing something like this: [1945 audio clips]
They’d just now be hearing about the final days of World War II because Regulus is a bit more than 79 light-years away. That means it takes more than 79 years for light – including radio waves – to travel from Earth to Regulus, or from Regulus to Earth. So the light we see from Regulus tonight actually left the star in 1945. And if anything dramatic were to happen to the star tonight, we wouldn’t know about it until 2103.
79 light-years is a huge distance. Light travels at 670 million miles per hour. That means Regulus is almost 500 trillion miles away – a five followed by 14 zeroes.
Such vast distances make many people skeptical that we could ever have a chat with another civilization. It might take generations from the time one side said “hello” until the other could respond. So some day we might hear a broadcast from another civilization. But we’ll probably never become best buds.
Look for Regulus to the upper left of the Moon in the evening twilight – a close neighbor that’s not close enough for a neighborly chat.
Script by Damond Benningfield