One of science’s most iconic photos, “Pale Blue Dot,” has just celebrated a very special birthday. A quarter of a century ago, on February 14, 1990, the Voyager 1 spacecraft turned around to snap photos of the planets behind it. Roughly four billion miles from Earth, it took six photos of Neptune, Uranus, Saturn, Jupiter, Earth and Venus.
The late astronomer Carl Sagan, who was part of Voyager 1’s team at the time, thought of the idea to have the probe turn around to look back towards home and take a “family photo.” Mars, Mercury and Pluto did not make it into the set, but the other six remained, one giving a very minuscule glimpse at the blue dot humans call home.
Voyager 1’s camera was turned off shortly after so its computer could be retasked, and the probe can no longer take photographs.
“Pale Blue Dot” quickly became an awe-inspiring photo, and became even more popular with the publication of Sagan’s 1994 book, Pale Blue Dot: A Vision of the Human Future in Space.
“That’s here. That’s home. That’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every ‘superstar,’ every ‘supreme leader,’ every saint and sinner in the history of our species lived there — on a mote of dust suspended in a sunbeam.”
Voyager 1 continues to send back data to this day, and according to NASA, the probe is “more than three times farther from Earth than it was on Valentine’s Day 25 years ago. Today, Earth would appear about 10 times dimmer from Voyager’s vantage point.”
In fact, Voyager 1 has traveled so far that it left the heliosphere and moved into interstellar space in August 2012. Since then it rode multiple “tsunami waves” created by massive bursts of solar wind that occur when the sun undergoes a coronal mass ejection.
Even then, Voyager 1’s mission is not just data transmission. It, along with its sister probe, Voyager 2, is carrying a double-sided, gold-covered LP with a vault of information about our little blue dot for any alien species that might eventually pick it up. Each LP holds words, photos, music and scientific data. The LPs were designed to hold that information for billions of years.
“Pale Blue Dot” may be over two decades old, but it’s still a captivating sight — and though it won’t send any more photos along its journey, consistent updates on both Voyager probes can be found on NASA’s Voyager website.
[Photo by NASA/JPL]