Less Than a Pale Blue Dot: 40 Years of Voyager

By Alysa Rogers

In 1977, now 40 years ago, Voyager 2 and Voyager 1 were launched into space for a completely unique journey out of the solar system. How did they get so far? A once-in-a-lifetime opportunity: every 176 years, the planets align perfectly (and no, mercury doesn’t go into retrograde). In 1965, it was calculated that a satellite launched at some time in the late 1970s would be able to visit Jupiter, Saturn, Uranus, and Neptune by slingshotting between using each planet’s gravity. So in 1972, they got to work on the Mariner Jupiter/Saturn 1977 project, so-called because NASA was willing to commit only to doing flybys of Jupiter and Saturn, leaving Uranus and Neptune out of the original name and plan.

After years of calculating and building the satellites, they were finally ready to launch. Voyager 2 launched on August 20th, soon followed by Voyager 1 on September 5th. And the waiting began. Finally, on March 9, 1979, Voyager 1 reached Jupiter and returned more than anyone could have hoped. Pictures sent over 588 million kilometers revealed discoveries of Jupiter’s rings, two new moons, lightning on the planet, and active volcanoes on Io, amongst others. Voyager 2 sent back even more, and similarly groundbreaking discoveries were made by both at Saturn in 1980 and 1981. Here, Voyager 1 veered up out of the planetary plane and out of the solar system, reaching interstellar space on August 25, 2012. Voyager 2, though, continued surfing gravitational waves to Uranus (reached in 1986) and Neptune (1989) in hopes of making similarly jaw-dropping discoveries—they did.

Finally, Voyager 2 began its journey out of the solar system that continues on today. While its cameras turned off to save power and memory soon after leaving Neptune, Voyager 1’s were still on and NASA turned them homeward, taking photos of our solar system as it sped away. While originally they were slightly reluctant to do so, Carl Sagan was able to convince them. And one of the most iconic images of Earth was taken, producing the photo now known simply as “Pale Blue Dot,” from Sagan’s speech on the photo.

“Pale Blue Dot,” with Earth circled in red

Despite the important scientific discoveries by Voyager, the mission is most famously characterized by the Golden Record compiled by a team headed by Carl Sagan. Because the satellite is traveling far beyond anything we’ve created before or since, the Golden Record is an attempt at encapsulating life on earth, including music from a wide variety of cultures and greetings in many languages, as well as pictures of landscapes and people. The purpose: reaching alien life. The Record is even bigger than that, though. Even after the sun has become a red giant and engulfed our tiny planet, Voyager will still be carrying this piece of us off into the depths of space. Billions of years from now, even after we are extinct and our “mote of dust” has been swept away, there will still be evidence that we were here.

Golden Record’s cover, with instructions to play it and a map to Earth based on major objects in space

 

Interested? Visit NASA’s website dedicated to the mission here: https://voyager.jpl.nasa.gov/

Sources:

Nelson, Jon. “The Golden Record Cove.” NASA, NASA, voyager.jpl.nasa.gov/golden-record/golden-record-cover/.

Nelson, Jon. “Voyager – Mission Timeline.” NASA, NASA, voyager.jpl.nasa.gov/mission/timeline/#event-pale-blue-dot-and-friends.

Greicius, Tony. “’Pale Blue Dot’ Images Turn 25.” NASA, NASA, 13 Feb. 2015, http://www.nasa.gov/jpl/voyager/pale-blue-dot-images-turn-25.

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