The closest star to our Sun, Proxima Centauri, lies about 4.2 light-years away , but even our most distant spacecraft hasn’t made it past a single light-day yet.

 

The closest star to our Sun, Proxima Centauri, lies about 4.2 light-years away — that’s nearly 40 trillion kilometers.

It feels “close” compared to the vastness of the galaxy, but even our most distant spacecraft hasn’t made it past a single light-day yet.

Voyager 1, launched in 1977, has been speeding away from Earth for 48 years and is now roughly 24.9 billion km (15.5 billion miles) out. Voyager 2 trails behind at about 21 billion km (13 billion miles). For scale, a light-day is about 26 billion km — the distance light travels in just 24 hours.

So after almost half a century, Voyager 1 hasn’t even ticked off the first day of a light-speed journey. If it were heading for Proxima Centauri at its current pace, the trip would take over 75,000 years.

And yet, these tiny machines, powered by decades-old technology, continue to send whispers from the edge of interstellar space — proof of just how vast and humbling our cosmic neighborhood truly is.

Science and Astronomy