in 1977 (before i was born!!), NASA scientists launched the voyager spacecrafts, which were intended for 5 year missions of solar system exploration! they each succeeded well beyond just taking pictures of jupiter and saturn! voyager 1 passed pioneer 10 on february 17, 1998 to become the most distant synthetic object in space!!! both voyagers continue to travel out in space, well beyond the confines of our solar system.
as of august 10, 2007, voyager 1 is 15.4 billion km (9,594,000,000 miles) away from earth! that's about 100 AU, or 100 times as far from us as we are from the sun. voyager 1 travels away from the solar system at a speed of 3.6 AU per year, which is 17 kilometers per second or 38,000 miles per hour!!!
one of my long-time heroes, carl sagan, was integrally involved with the planning of the voyager missions. he had the brilliant idea to turn the voyager 1 spacecraft around just before it left the confines of our solar system to take an image o the earth on february 14, 1990. earth encompassed one single pixel of that entire image. if you've never read sagan's reaction to this phenomenon, please read this!!
carl sagan also chaired the committee that determined what message should be sent out into space on the voyager spacecrafts to portray the uniqueness of life on earth. they included 115 images, nature sounds of earth, 90 minutes of music and spoken greetings from 55 different languages among other things. the message is carried by a 12-inch gold-plated copper disk phonograph "golden record"!!
for a bit of perspective... while it is exciting to think about the huge distance traveled by the voyager space crafts over the last 30 years... the nearest star to our sun is 4.2 light-years away. that is roughly 200,000 AU. at its current speed of 3.6 AU per year, it will take 56,000 years for voyager 1 to reach the next star!! let's hope that some other civilizations in the universe started sending machines out into space a long long time ago and hopefully sent them off at much much faster speeds!!