Earth's past seen from light years away

When we look up at the stars from Earth, we know they are light years away.

In a way, according to a Popular Science article, we are actually looking back in time. The light we are seeing could be from millions of years ago.

Now, what if we reverse the process? What do we look like to other planets? They would also be staring into Earth’s past, according to the article. FOX 13’s meteorologist Dave Osterberg discussed the article during his “Dave O the Science Pro” segment on Tuesday.

Let’s say you’re 39 light-years away in Trappist-1, which is a potentially habitatable seven-planet system.

“You’d be watching Americans boogey to disco,” Osterberg said. “Space Invaders would be in the arcades.”

Now, let’s go even further. How about 642 light-years away?

“If there is somebody on a planet 642 light-years away. You know what they are seeing right now? Medieval Europe,” Osterberg said. “They’re looking at the plague. That’s what they are seeing.”

Okay, what if someone is watching us from Andromeda, our nearest neighboring galaxy which is 2.5 million light-years away? According to Popular Science, they would witness our ancient ancestors learned to wield tools, or butchering meals with stone.

Let’s consider a galaxy 70 million light-years away. Tyrannosaurus rex wandering around North America with its large jaws and short arms.

Last one. We promise. Inhabitants of a planet located 4.5 billion light-years away would witness an even more extraordinary moment in Earth’s history.

“A mars-sized rock slamming into Earth creating the moon,” Osterberg said. “They’re not watching this segment. They’re watching the moon being made.”

Interesting, right? You can read and learn more about this topic from Popular Science.