Carrying the Sounds of Earth record to the distant stars, Voyager 1 is approaching the cusp of our solar system in search of alien civilizations that can play 8-track tapes.
For a mobile music player that's 100,000 times less powerful than a crummy 8GB iPod Nano, Voyager 1 is mighty awesome.
The NASA space probe was launched 35 years ago today, on September 5, 1977, three months after a new space opera called "Star Wars" hit theaters. Programmed to explore the outer planets, it has traveled farther than any man-made object since then, and is leaving our solar system for interstellar space.
With its 68-kilobyte computer memory and 8-track tape recorder, Voyager is bringing old-timey tech to the stars. It's currently some 11.3 billion miles from the sun in the heliosheath, the region where the solar wind slows down as it hits gas and dust outside our solar system.
It's unknown when the probe will actually exit our system for the interstellar medium. It could take weeks, months, or years.
Indeed, scientists had believed that by now, Voyager 1 would have already left the heliosphere, the area were charged solar particles prevail. But they are still waiting for signs that would suggest the machine has reached the heliopause, the wind's limits.
John Hopkins University space physicist Robert Decker and colleagues report in Nature that the craft is now in a dead zone where particles have nearly zero velocity.
"Based on the changes we have seen in the Voyager 1 data during the past year, I would expect that Voyager 1 will cross the heliopause within one year," Space.com quoted Decker as saying.
Piecing together the data from Voyager 1 is a puzzler for scientists since little is known about the fringes of the solar system. Meanwhile, it takes 17 hours to send a command to the probe, which has a transmitter that's about as powerful as a refrigerator light bulb. Still, four of its instruments are still returning data on local conditions.
Voyager's Golden Record has a collection of images and sounds from Earth, including greetings in 54 languages. They range from the folksy "Have you eaten yet? Come visit us if you have time" (Amoy) to the downright geeky "Greetings from a computer programmer in the little university town of Ithaca on the planet Earth" (Swedish).
Assuming there are aliens out there who love old-school analog sounds, we might make some friends, now or in a million years.
The late, great astronomer Carl Sagan, who helped organize the contents of the disc, said of Voyager, "The spacecraft will be encountered and the record played only if there are advanced spacefaring civilizations in interstellar space. But the launching of this bottle into the cosmic ocean says something very hopeful about life on this planet."