Today marks the thirtieth anniversary of the launch of Voyager 1.
Thirty years ago today, the Voyager 1 space probe — a one-ton robotic craft whose long antennas make it look rather like a spider the size of a school bus — was launched from Cape Canaveral, Fla., on a mission to reconnoiter Jupiter and Saturn. To succeed, Voyager would have to survive five years in the vacuum of space, where it would encounter cosmic rays, solar flares, the hurtling rocks and sand of the asteroid belt, and Jupiter’s intense radiation bands.
The probe did all that, transmitting back reams of scientific data and memorable color photos: of the sputtering red and yellow volcanoes of Jupiter’s moon Io; of the shimmering blue ice that shrouds Io’s fellow satellite Europa, beneath which a liquid ocean is suspected to dwell; of Saturn’s myriad rings and the murky mysteries of its orange satellite, Titan, whose hazy atmosphere is thought to approximate that of the early Earth.
Having accomplished its mission, Voyager 1 might have quietly retired. Instead it remains active to this day, faithfully calling home from nearly 10 billion miles away — so great a distance that its radio signals, traveling at the speed of light, take more than 14 hours to reach Earth. From Voyager’s perch, the Sun is just another star, south of Rigel in the constellation Orion, and the Sun’s planets have faded to invisibility.
Like its twin, Voyager 2 — which dallied behind to examine the outer planets Uranus and Neptune and is departing the solar system on another trajectory — Voyager 1 is approaching the edge of the solar system. That limit is defined by a teardrop-shaped bubble called the heliosphere, where the solar wind (particles blown off the Sun’s outer atmosphere) comes to a halt.
If all continues to go well, Voyager should pierce the heliosphere’s outer skin by around 2015. It will then depart into the void of interstellar space, where it is destined to wander among the stars forever.
Mindful of this mind-boggling fact, the astronomers Carl Sagan and Frank Drake persuaded NASA to attach a gold-plated phonograph record to each of the Voyager spacecraft.
Containing photographs, natural sounds of Earth and 90 minutes of music from all over our world, the record was intended to preserve something of human culture beyond what an intelligent extraterrestrial, encountering the craft at some far-distant time and place, might infer from the spacecraft itself.
The information etched into the grooves of the Voyager record is expected to last at least one billion years. That’s a long time: A billion years ago, life on Earth was first venturing forth from the seas.
As for the Golden Record itself, it may be the only thing left of our civilization for anyone else to find. The inscription on it reads, “This is a present from a small, distant world, a token of our sounds, our science, our images, our music, our thoughts and our feelings. We are attempting to survive our time so we may live into yours.”
Right now I’d settle for making it to January 2009.