In August of 1977, the first of two identical robotic probes was launched from Cape Canaveral, Florida, bound for our outermost planets and beyond. Voyager 1 and Voyager 2 have each traveled more than 10 billion miles in the past 40 years, sending back invaluable observations and images. They discovered two dozen new moons, discovered active volcanoes on Jupiter’s moon Io, took a famous “family portrait” of our solar system, and much more. Voyager 1 recently became the first spacecraft to leave the heliosphere and enter interstellar space. The Voyagers are also famous for being our most remote emissaries, carrying with them identical “golden records” with images and sounds from Earth. On this 40th anniversary of the first launch, a look back at the still-running Voyager mission follows.
Voyager's 40th Anniversary
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Voyager 2 launches from Cape Canaveral, Florida, aboard a Titan III-Centaur launch vehicle on August 20, 1977, about two weeks before the September 5 launch of Voyager 1. The two spacecraft were sent on different trajectories, and Voyager 1 was put on a path to reach its planetary targets, Jupiter and Saturn, ahead of Voyager 2. #
NASA / JPL-Caltech -
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Flying aboard Voyagers 1 and 2 are identical "golden" records, carrying the story of Earth far into deep space. The 12 inch gold-plated copper discs contain greetings in 60 languages, samples of music from different cultures and eras, and natural and man-made sounds from Earth. They also contain electronic information that an advanced technological civilization could convert into diagrams and photographs. The cover of each gold-plated aluminum jacket, designed to protect the record from micrometeorite bombardment, also serves a double purpose in providing the finder a key to playing the record. The explanatory diagram appears on both the inner and outer surfaces of the cover, as the outer diagram will be eroded in time. #
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As NASA's two Voyager spacecraft travel out into deep space, they also carry a small American flag along with the Golden Record. This picture shows John Casani, Voyager project manager in 1977, holding a small Dacron flag that was folded and sewed into the thermal blankets of the Voyager spacecraft before they launched. In the background stands Voyager 2 before it headed to the launch pad. The picture was taken at Cape Canaveral, Florida, on August 4, 1977. #
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This picture of a crescent-shaped Earth and moon—the first of its kind ever taken by a spacecraft—was recorded September 18, 1977, by NASA's Voyager 1 when it was 7.25 million miles (11.66 million kilometers) from Earth. The moon is at the top of the picture and beyond the Earth as viewed by Voyager. In the picture are eastern Asia, the western Pacific Ocean and part of the Arctic. Voyager 1 was directly above Mt. Everest (on the night side of the planet at 25 degrees north latitude) when the picture was taken. The photo was made from three images taken through color filters, then processed by the Jet Propulsion Laboratory's Image Processing Laboratory. Because the Earth is many times brighter than the moon, the moon was artificially brightened by a factor of three relative to the Earth by computer enhancement so that both bodies would show clearly in the print. Voyager 2 was launched August 20, 1977, followed by Voyager 1 on September 5, 1977, en route to encounters at Jupiter in 1979 and Saturn in 1980 and 1981. JPL manages the Voyager mission for NASA. #
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Musician Chuck Berry (left) and astronomer Carl Sagan on stage at a Voyager 2 Neptune flyby celebration in August of 1989. Berry's "Johnny B. Goode" is the only rock-and-roll song on the golden records currently traveling into interstellar space aboard Voyagers 1 and 2. #
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This photo of Jupiter's satellite Io was taken by Voyager 1 about 4:30 p.m. (PST) March 2, 1979. The spacecraft was about 5 million miles (8.3 million kilometers) away. Voyager 1 was mapping Jupiter with cameras and an infrared instrument at the time the picture was taken. The hemisphere seen here is the one that always faces away from Jupiter. This photo shows details on Io never before seen. The smallest features are about 38 miles (70 kilometers) across. Near the center and slightly to the right can be seen several round features with dark centers and bright rims. They may be the first craters ever observed on Io. #
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Voyager 1 image of Io showing the active plume Loki on its limb. The heart-shaped feature southeast of Loki consists of fallout deposits from active plume Pele. The images that make up this mosaic were taken from an average distance of approximately 490,000 kilometers (340,000 miles). #
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This Voyager 1 image mosaic shows Io's south polar region. Haemus Mons, a 10-kilometer-high (32,000-foot) mountain is at right. Elsewhere, much flatter volcanic plains, eroded volcanic plateaus, and crater-like volcanic calderas dominate the scene. The composition of the prevalent volcanic plains of Io could consist dominantly of sulfur with a thin discontinuous coating of sulfur dioxide frost or of silicates (such as basalt) coated with sulfurous condensates. #
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Vibrant bands of clouds carried by winds that can exceed 400 mph continuously circle Jupiter's atmosphere. Such winds sustain spinning anticyclones like the Great Red Spot, a raging storm three-and-a-half times the size of Earth located in Jupiter’s southern hemisphere. In January and February 1979, NASA's Voyager 1 spacecraft zoomed toward Jupiter, capturing hundreds of images during its approach, including this close-up of swirling clouds around Jupiter's Great Red Spot. This image was assembled from three black-and-white negatives. The observations revealed many unique features of the planet that are still being explored to this day. #
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This picture of a multi-ring basin on Callisto was taken the morning of March 6, 1979, from a distance of about 200,000 kilometers. The complicated circular structure seen at left-center is similar to the large circular impact basins that dominate the surface of the Earth's moon and also the planet Mercury. The inner parts of these basins are generally surrounded by radially lineated ejecta and several concentric mountainous ring structures that are thought to form during the impact event. The great number of rings observed around this basin on Callisto is consistent with its low planetary density and probable low internal strength. #
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Voyager 1 took this photo of Jupiter and two of its satellites (Io, left, and Europa) on February 13, 1979. Io is about 350,000 kilometers (220,000 miles) above Jupiter's Great Red Spot; Europa is about 600,000 kilometers (375,000 miles) above Jupiter's clouds. Although both satellites have about the same brightness, Io's color is very different from Europa's. Io's equatorial region show two types of material—dark orange, broken by several bright spots—producing a mottled appearance. The poles are darker and reddish. Preliminary evidence suggests color variations within and between the polar regions. Io's surface composition is unknown, but scientists believe it may be a mixture of salts and sulfur. Europa is less strongly colored, although still relatively dark at short wavelengths. Jupiter is about 20 million kilometers (12.4 million miles) from the spacecraft. #
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Voyager 1 and 2 observed radio signals from lightning which were interpreted as being from a persistent, low-latitude storm system which was extended in longitude, perhaps similar to the region highlighted on this Voyager 2 image acquired on August 4, 1981, from a distance of 21 million kilometers (13 million miles). #
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Multiple impact craters are seen on the ancient surface of Saturn's moon Rhea in this picture taken by Voyager 1 on November 12, 1980, at a range of 73,000 kilometers (45,000 miles). #
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This picture shows a Voyager 2 high-resolution view of Saturn's rings on August 23, 1981, at a range of 3.3 million kilometers (2 million miles). The planet’s limb is visible through the C ring and the inner part of the B ring. #
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Voyager 1 looked back at Saturn on November 16, 1980, four days after the spacecraft flew past the planet, to observe the appearance of Saturn and its rings from this unique perspective. A few of the spokelike ring features discovered by Voyager appear in the rings as bright patches in this image, taken at a distance of 5.3 million kilometers (3.3 million miles) from the planet. Saturn's shadow falls upon the rings, and the bright Saturn crescent is seen through all but the densest portion of the rings. #
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This is an image of the planet Uranus taken by the spacecraft Voyager 2. NASA's Voyager 2 spacecraft flew closely past distant Uranus, the seventh planet from the sun, in January 1986. #
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This computer-assembled mosaic of Miranda includes many of the high-resolution frames obtained by Voyager 2 during its close flyby of the Uranian moon. Miranda, roughly 500 kilometers (300 miles) in diameter, exhibits varied geologic provinces, seen in this mosaic of clear-filter, narrow-angle images from January 24, 1986. On Miranda, ridges and valleys of one province are cut off against the boundary of the next province. Probable compressional (pushed-together) folded ridges are seen in curvilinear patterns, as are many extensional (pulled-apart) faults. Some of these show very large scarps, or cliffs, ranging from 0.5 to 5 kilometers (0.3 to 3 miles) in height—that is, higher that the walls of the Grand Canyon on Earth. #
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This image of Miranda, obtained by Voyager 2 on approach, shows an unusual "chevron" figure and regions of distinctly differing terrain on the Uranian moon. Voyager was 42,000 kilometers (26,000 miles) away when its narrow-angle camera acquired this clear-filter view. #
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This mosaic of the four highest-resolution images of Ariel represents the most detailed Voyager 2 picture of this satellite of Uranus. The images were taken through the clear filter of Voyager's narrow-angle camera on January 24, 1986, at a distance of about 130,000 kilometers (80,000 miles). Ariel is about 1,200 kilometers (750 miles) in diameter; and much of its surface is densely pitted with craters 5 to 10 kilometers (3 to 6 miles) across. These craters are close to the threshold of detection in this picture. #
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NASA's Voyager 2 spacecraft gave humanity its first glimpse of Neptune and its moon Triton in the summer of 1989. This picture of Neptune was produced from the last whole-planet images taken through the green and orange filters on the Voyager 2 narrow-angle camera. The images were taken on August 20, 1989, at a range of 4.4 million miles from the planet, 4 days and 20 hours before closest approach on August 25. The picture shows the Great Dark Spot and its companion bright smudge; on the west limb the fast-moving bright feature called "Scooter" and the little dark spot are visible. These clouds were seen to persist for as long as Voyager's cameras could resolve them. #
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This Voyager 2 high-resolution color image provides obvious evidence of vertical relief in Neptune's bright cloud streaks. These clouds were observed at a latitude of 29 degrees north near Neptune's east terminator, the "line" on a planet where daylight meets darkness. The resolution of this image is 6.8 miles per pixel. The width of the cloud streaks range from 31 to 124 miles, and their shadow widths range from 18 to 31 miles. Cloud heights appear to be around 31 miles. #
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The Voyager 2 mission control room at NASA's Jet Propulsion Laboratory near Pasadena, California, is also in charge of the Magellan probe and the Deep Space Network. #
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Voyager 2 imaging-team member Carolyn Porco (center) and other scientists at NASA's Jet Propulsion Laboratory await images of Neptune's moon Triton taken by the Voyager 2 probe in August 1989. #
Roger Ressmeyer / Corbis / VCG via Getty -
This dramatic view of the crescents of Neptune and its moon Triton was acquired by Voyager 2 approximately three days, six-and-a-half hours after its closest approach to Neptune. The spacecraft was at a distance of 4.86 million kilometers (3 million miles) from Neptune when these images were shuttered, so the smallest detail discernible is approximately 90 kilometers (56 miles). Neptune does not appear as blue from this viewpoint because the forward-scattering nature of its atmosphere is more important than its absorption of red light at this high-phase angle (134 degrees). #
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Astronomer Carl Sagan speaks at a news conference where NASA made available the last pictures taken by Voyager 1, which show the solar system as a "family portrait" viewed from the outside. #
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This narrow-angle color image of the Earth, dubbed "Pale Blue Dot," is a part of the first-ever "portrait" of the solar system taken by Voyager 1. The spacecraft acquired a total of 60 frames for a mosaic of the solar system from a distance of more than 4 billion miles from Earth and about 32 degrees above the ecliptic. From Voyager's great distance Earth is a mere point of light, less than the size of a picture element even in the narrow-angle camera. Earth was a crescent only 0.12 pixels in size. Coincidentally, Earth lies right in the center of one of the scattered light rays resulting from taking the image so close to the sun. In 1994, Carl Sagan said of this image: "That's here. That's home. That's us. On it, everyone you ever heard of, every human being who ever lived, lived out their lives. The aggregate of all our joys and sufferings, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilizations, every king and peasant, every young couple in love, every hopeful child, every mother and father, every 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." #
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At the center of this image is the star AC +79 3888, also known as Gliese 445, located 17.6 light-years from Earth. NASA's Voyager 1 spacecraft, which is on a trajectory out of our solar system, is headed toward an encounter with AC +79 3888. In about 40,000 years, Voyager 1 will be closer to this star than our own sun. The image was taken by the Samuel Oschin Telescope near San Diego, California, on April 22, 1998. #
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