Rufus Boyd

In November, a NASA spacecraft that has been drifting through space since 1977 will be so far from Earth that light itself takes a full day to reach it. Send it a message on Monday morning, you won't hear back until Wednesday. It's called Voyager 1. For more than 45 years it has been gliding at 38,000 miles an hour on a straight line out of our solar system. It has not adjusted course since 1980. Every year it loses about 4 watts of power from the small chunks of plutonium that keep it warm and transmitting. It's like your phone's battery shrinking a little each year, except the spacecraft weighs as much as a small car and nobody can walk over to plug it in. The whole spacecraft runs on 69KB of computer memory. That is less than a single photo on your phone, and its signal home crawls back at 160 bits per second, slower than dial-up internet from the 1990s. A modern smartphone has roughly 175,000 times more memory than the computer that left Earth before most people alive today were born. NASA built it to last five years. The original mission ended at Saturn in 1980. Everything after that, leaving our solar system in 2012 to become the most distant object humanity has ever built, was a bonus. The plutonium core will probably run out around 2036. That gives us maybe a decade of data from a place no other machine will reach in our lifetime. Then the radio goes quiet for good. Bolted to its side is a gold-plated copper disc carrying 116 images, 90 minutes of music from around the world, natural sounds of Earth, and greetings in 55 languages. In about 40,000 years it will drift within 1.6 light-years of a small red star called Gliese 445. If anyone ever finds it, nobody we know will be alive to hear about it.