The Voyager Spacecraft Interstellar Record

On August 20th and September 5th 1977, two extrordinay spacecraft called Voyager were launched to the stars. After what pormises to be a detailed and thoroughly dramatic exploration of the outer solar system from Jupiter to Uranus between 1979 and 1986, these space vehicles left the solar system - emissaries of Earth to the realm of the stars. Affixed to each Voyager craft is a gold-coated copper phonograph record as a message to possible extra-terrestrial civilizations that might encounter the spacecraft in some distant space and time. Each record contains 118 photographs of our planet, ourselves and our civilization; almost 90 minutes of the wolrd's greatest music, an evolutionnary audio essay on "The sounds of the Earth"; and greetings in almost sixty human languages ( and one cetacean language ! ), including salutations from the president of the United States and Secretary General of the United Nations.

"I had monuments made of bronze, lapis, lazuli, albaster...and white limestone...and inscriptions of baked clay...I desposited them in the foundations and left for future times" _ Esarhaddon, king of Assyria, Seventh century B.C.

"So deep is the conviction that there must be life out there beyhond the dark, one thinks if they are more advanced than ourselves they may come adross space at any moment, perhaps in our generation. Later, contemplating the infinity of time, one wonders if perchance their message came long ago, hurtling into the swamp muck of the steaming coal forests, the bright projectile clambered over by hissing reptiles, and the delicate instruments running mindlessly down with no report." _ Loren Eiseley.

"I think an extraterrestrial message will be much more like a discipline of learned study than like a series of headlines" _ Philip Morrison.

"It's gayer than a greeting and it's sadder than a sigh" _ "Aloha Oe" Don Blanding.

"Be not afeard. The isle is full of noises, Sounds and Sweet airs, that give delight, and hurt not"_ Shakespeare, The tempest.

"As the eyes are framed for astronomy so the ears are framed for the moments of harmony" _ Plato, Republic.

"Music is harmony of heaven and earth" _ Chinese musical text yueh-chi, second century B.C.

"Look here, upon this picture, and on this...the front of Jove himslef"_ William Shakespeare, hamlet, Act3, scen 4.

"The Universe is a huge machine that gives life. We ignore when waves will reveal an unknown Earth and what it will look like either. But tomorrow, or within a century, something will come from up there, something different, a message written by an Intelligence unfamiliar to Mankind. I'm waiting... One day, me or my far descendants, we will have the answer." _ Jean Heidmann.

The illustration at the top of this page is the gold-plated aluminum cover used to enclose the Voyager records. The etchings on the cover provide instructions for playing the record to whoever finds it. The Voyager record is secured in plain view on the outside of the Voyager Spacecraft with a spider mounting to which is also affixed the stylus cartridge used to play the disc. The record itself is actually made of two copper mothers bonded back-to-back. The side that faces inward towards the spacecraft is best protected, and contains all 122 images included on the record, as well as human and cetacean greetings, the sounds of earth, and a third of the music selections. The outer side consists entirely of music selections. NASA's Golden Record Page provides a list of the contents along with the ability to see and listen to much of the material. Note that the NASA write-up mentions only 115 images because they miscounted their listing by one and don't include the six images of text, the first two displaying President Carter's greeting and the last four displaying the names of Congress members on committees relevant to NASA. They also changed the original image of Cathy Rigby to another gymnast due to copyright issues.

The late Carl Sagan headed the team that chose the contents of the Voyager record. He was also responsible for the design of the plaques included with the Pioneer 10 and 11 Spacecraft and the LAGEOS 1 Satellite.

Hydrogen Transition This illustration on the lower right of the Voyager record cover could be considered the "Rosetta Stone" of the record, as it provides the key to interpreting the remaining cover illustrations. This illustrates the hyperfine transition of the hydrogen atom where it changes between its two lowest states. The time interval for this is a mathematical constant equal to 0.7 billionths of a second, or more precisely 7.04024183647E-10 seconds. The 1 between the two states indicates the length of the transition should be equal to a binary 1. The binary numbering system, with just two symbols, 0 and 1, is the simplest numbering system, and is more likely to be understood by other civilizations than our decimal system adopted simply because humans have 10 fingers. With hydrogen being the most abundant element in the galaxy, any advanced civilization likely to encounter the Voyager should be able to interpret the meaning of this diagram.


Stylus Cartridge Playing Voyager Record- Top View This is a top-down view of the Voyager record showing the stylus cartridge in place to play the disc. The position of the cartridge implies the record groove is to be played from the outside in. The symbols around the periphery of the record are a binary representation of the time required for one revolution of the record where a binary 0 is represented by a dash and a binary 1 is represented by the same vertical symbol used with the hydrogen transition above. Since leading 0's are meaningless in the binary numbering system, the number would be read off in a counter clockwise direction starting above the stylus cartridge. This also implies the record is supposed to spin clockwise relative to a stationary stylus, as that's the way the illustration needs to move to read off the binary number. The number around the periphery is 100110000110010000000000000000000 which converts to 5,113,380,864 in decimal. Multiplying this by 7.04024183647E-10 seconds yields 3.5999 seconds, the length of time for one rotation of the record.


Stylus Cartridge Playing Voyager Record- Side View This is a side view of the record and stylus cartridge, with two large bars enclosing a binary number indicating the length of time required to play one side of the record. Doing the math again, we have 1000010110000000000000000000000000000000000 which converts to 4,587,025,072,128 in decimal. Multiplying by 7.04024183647E-10 seconds yields 3229.377 seconds, or about 53.8 minutes to play one side.


Waveform Recovered from Voyager Record These waveform representations of the picture signal recorded in the groove provide an explanation for how the images are to be constructed. Someone analyzing the signal on the record would be able to recognize the image portion by similar looking groups of waveforms, with each group preceded by the symmetrical waveform seen in the top left corner of this picture. Each of these groups would be further subdivided into 512 individual signals, the first three of which are shown here labeled in binary notation as 1, 10, and 11 (decimal 1, 2, and 3). Just below the waveform drawing is a conceptual drawing of what they represent, again labeled 1, 10, and 11. The conceptual drawing indicates that each of the three signals represents a "line" of the final image with each line being drawn in a staggered, non-overlapping fashion. All 512 signals taken together constitute a single image. This staggered line image is the same way television images are drawn by the electron gun inside the CRT, except in the case of modern TV the lines are arranged horizontally and interlacing is used. There is also a binary number of 101101001100000000000000 under signal 1 which converts to 11,845,632 in decimal. Multiplying this by the constant of 7.04024183647E-10 seconds yields 0.0083396 seconds. So it takes about 8 milliseconds to draw one line of an image. It might be a considerable jump for someone to look at this one portion of the record cover and interpret what the image waveforms are supposed to be, but the two images below it provide further reinforcement of the desired interpretation.


One Complete Image Scan from Voyager Record This drawing expands on the concepts presented in the waveform drawing by showing what a complete image would look like. There's a binary number 1000000000 drawn vertically above the last line of the image. This converts to 512 in decimal and indicates that the image consists of 512 lines, which would concur with the 512 similar signals within each waveform as described above. There is also a binary number of 10000 at the left end of the picture that converts to decimal 16. The interpretation of this seems somewhat cryptic, but it means that there are 16 levels of gray within each line. In other words the image quality in terms of grayscale is about equal to a photocopy of a photograph. The image quality in terms of resolution would be somewhat less than a photocopy as it equals about 500 dots along each line of the image. Thus each image has about the same number of dots along each line as there are lines in the complete image. if you think in terms of pixels rather than lines, this ratio results in square pixels.


Calibration Image on Voyager Record This picture of a circle is the first image recorded on the record. It is intended for calibration purposes to insure the signal on the disc is being decoded properly, and the right ratio of horizontal to vertical height is used in picture reconstruction. For example, if someone decoded this picture and the circle instead looked like an oval that was wider than it was tall, they would probably guess that they need to draw the picture lines closer together.


Pulsar Map on Voyager Record This picture has nothing to do with interpreting the disc contents, but rather is a pulsar map indicating the solar system from which the Voyager spacecraft originated. The cover of the Voyager record also contains an ultra-pure source of Uranium-238 to serve as a radioactive clock for determining the record's age. This same pulsar map as well as hydrogen atom drawing were also included on the Pioneer 10 and 11 Plaques. Each pulsar has its own distinct and rapid pulsing radio frequency that is very slowly changing with absolute linearity. It's likely that other civilizations of sufficient advancement will be familiar with these and their rates of change. The pulsar map shows fourteen pulsars and their directions from the sun along with the current frequency of the pulsar in binary notation. The horizontal line extending to the right with no binary number attached is a pointer from the sun to the center of the galaxy.


Solar Spectrum from Voyager Record The Voyager record contains about 20 color pictures, and at first it might seem a mystery how these could be extracted from 16 levels of gray. This picture of the solar spectrum is the first color image on the record, and someone recovering the image would note that it is actually recorded on the record three times in succession, with only the gray levels being different between the three recordings. The black absorption lines extending through the rainbow pattern are distinct for any G2 star like our own sun. A civilization familiar with solar spectroscopy should be able to recognize this as the red, green, and blue portion of a solar spectrum. They should then realize that the color image can be reconstructed by making a composite of the three images, one on top of the other, with the 16 shades of gray being interpreted as 16 shades of red, green, or blue in each layer of the image. By adjusting the color values assigned to each shade of gray, they will be able to reconstitute this known image of a solar spectrum and then use those color settings to properly view the remaining color images on the record. This is the same RGB technique used with present-day computers to determine exact colors. Sixteen levels of gray corresponds to 4 bits (2 to the fourth power), so the color images on the Voyager record have a combined color depth of 12 bits which permits a total of 4096 colors (2 to the twelfth power). By comparison, a common color setting for web browsing is 16-bit or 65,536 colors, and most computers manufactured today can do 32-bit color.

Greetings to the Universe in 55 Different Languages

Sumerian Arabic Urdu Italian Ila (Zambia)
Akkadian Romanian Hindi Nguni Nyanja
Hittite French Vietnamese Sotho Swedish
Hebrew Burmese Sinhalese Wu Ukrainian
Aramaic Spanish Greek Korean Persian
English Indonesian Latin Armenian Serbian
Portuguese Kechua Japanese Polish Luganda
Cantonese Dutch Punjabi Nepali Amoy (Min dialect)
Russian German Turkish Mandarin Chinese Marathi
Thai Bengali Welsh Gujarati Kannada
Telugu Oriya Hungarian Czech Rajasthani

Sounds of Earth

Music of The Spheres Volcanoes, Earthquake
, Thunder
Mud Pots
Wind, Rain, Surf Crickets, Frogs Birds, Hyena, Elephant
Chimpanzee Wild Dog Footsteps, Heartbeat,
Fire, Speech The First Tools Tame Dog
Herding Sheep, Blacksmith, Sawing Tractor, Riveter Morse Code, Ships
Horse and Cart Train Tractor, Bus, Auto
F-111 Flyby, Saturn 5 Lift-off Kiss, Mother and Child Life Signs, Pulsar

Music On Voyager Record

  • Bach, Brandenburg Concerto No. 2 in F. First Movement, Munich Bach Orchestra, Karl Richter, conductor. 4:40
  • Java, court gamelan, "Kinds of Flowers," recorded by Robert Brown. 4:43
  • Senegal, percussion, recorded by Charles Duvelle. 2:08
  • Zaire, Pygmy girls' initiation song, recorded by Colin Turnbull. 0:56
  • Australia, Aborigine songs, "Morning Star" and "Devil Bird," recorded by Sandra LeBrun Holmes. 1:26
  • Mexico, "El Cascabel," performed by Lorenzo Barcelata and the Mariachi México. 3:14
  • "Johnny B. Goode," written and performed by Chuck Berry. 2:38
  • New Guinea, men's house song, recorded by Robert MacLennan. 1:20
  • Japan, shakuhachi, "Tsuru No Sugomori" ("Crane's Nest,") performed by Goro Yamaguchi. 4:51
  • Bach, "Gavotte en rondeaux" from the Partita No. 3 in E major for Violin, performed by Arthur Grumiaux. 2:55
  • Mozart, The Magic Flute, Queen of the Night aria, no. 14. Edda Moser, soprano. Bavarian State Opera, Munich, Wolfgang Sawallisch, conductor. 2:55
  • Georgian S.S.R., chorus, "Tchakrulo," collected by Radio Moscow. 2:18
  • Peru, panpipes and drum, collected by Casa de la Cultura, Lima. 0:52
  • "Melancholy Blues," performed by Louis Armstrong and his Hot Seven. 3:05
  • Azerbaijan S.S.R., bagpipes, recorded by Radio Moscow. 2:30
  • Stravinsky, Rite of Spring, Sacrificial Dance, Columbia Symphony Orchestra, Igor Stravinsky, conductor. 4:35
  • Bach, The Well-Tempered Clavier, Book 2, Prelude and Fugue in C, No.1. Glenn Gould, piano. 4:48
  • Beethoven, Fifth Symphony, First Movement, the Philharmonia Orchestra, Otto Klemperer, conductor. 7:20
  • Bulgaria, "Izlel je Delyo Hagdutin," sung by Valya Balkanska. 4:59
  • Navajo Indians, Night Chant, recorded by Willard Rhodes. 0:57
  • Holborne, Paueans, Galliards, Almains and Other Short Aeirs, "The Fairie Round," performed by David Munrow and the Early Music Consort of London. 1:17
  • Solomon Islands, panpipes, collected by the Solomon Islands Broadcasting Service. 1:12
  • Peru, wedding song, recorded by John Cohen. 0:38
  • China, ch'in, "Flowing Streams," performed by Kuan P'ing-hu. 7:37
  • India, raga, "Jaat Kahan Ho," sung by Surshri Kesar Bai Kerkar. 3:30
  • "Dark Was the Night," written and performed by Blind Willie Johnson. 3:15
  • Beethoven, String Quartet No. 13 in B flat, Opus 130, Cavatina, performed by Budapest String Quartet. 6:37

Voyager Record Photograph Index
The following is a listing of pictures electronically placed on the phonograph records which are carried onboard the Voyager 1 and 2 spacecraft.