For the first time in humanity's long history, a human-made object will soon be a full light-day away from our home planet.

Space, as they say, is pretty big, and human-made objects are slow. The record speed any human has ever traveled was set by Apollo 10 back in 1969, and has not been broken since. The fastest human spaceflight remains 39,937.7 kilometers per hour (24,816.1 miles per hour), and at those speeds, it would take 3,730 hours to travel just 1 astronomical unit (AU), the distance between the Earth and the Sun. 

At around 155 days, that's an unacceptable travel time to (for example) slam into the Sun. And while it takes you 155 days to get wherever it is you went, light and communications from Earth would reach you in about 8 minutes and 20 seconds, really rubbing it in how great it is to be massless. 

But we will get a real reminder of the vast distance and incredible speed of light in late 2026, when Voyager 1 becomes the first human-made object to reach one light-day away from Earth.  

This spacecraft was launched in 1977 and has been traveling ever since. At the time of writing, it is around 169.5 AU from the Earth, having become the first spacecraft to go beyond the heliosphere, cross the heliopause, and enter interstellar space. At its current position, it takes 23 hours, 29 minutes, and 27 seconds for signals from Earth to reach the spacecraft. At its current speed of about 61,198 kilometers per hour (38,027 miles per hour), it will still take over a year to widen that light-distance to a full 24 hours.

When it does reach 25.9 billion kilometers (16 billion miles) from Earth, a journey that took nearly 50 years, it will finally be the distance that light can travel in a day.