ATLANTA -- In what NASA calls a historic moment, the space agency announced on Thursday that the first human-made object officially left our solar system in 2012 as it crossed into interstellar space.
NASA scientists who continue to track the 36-year-old planetary space probe, Voyager 1, discovered that recent transmissions from the craft indicate it left our "solar bubble" in August 2012, and moved into a region filled with plasma and ionized gases which originated from massive stars millions of years ago.
However, Voyager remains under trace influences of our Sun.
"No one has been to interstellar space before, and it's like traveling with guidebooks that are incomplete," Voyager project scientist Ed Stone of the California Institute of Technology in Pasadena said. "Still, uncertainty is part of exploration. We wouldn't go exploring if we knew exactly what we'd find."
Due to the craft's age and older technology, Voyager cannot tell NASA exactly where it is nor does it have an operating plasma sensor to detect recent output from the Sun's Heliosphere which reaches out past the outer planets.
Scientists instead used data from a powerful burst of solar wind from the Sun which occurred in March 2012. Thirteen months later, the that solar burst eventually reached Voyager and the craft detected that it was forty times denser. They compared this data with a similar dense solar wave during 2012.
"Now that we have new, key data we believe this is mankind's historic leap into interstellar space," Stone explained. "The Voyager team needed time to analyze those observations and make sense of them. But we can now answer the question we've all been asking, 'Are we there yet?' Yes, we are."
Relaying new data every day to NASA's Jet Propulsion Laboratory, the craft's transmitter operates on 22 watts, the power of a small light bulb.
Moving at the speed of light, Voyager's transmissions of data arrives at NASA's Deep Space Network big dish antenna stations seventeen hours later where it is then processed.
"We looked for the signs predicted by the models that use the best available data, but until now we had no measurements of the plasma from Voyager 1," said Stone.
Voyage 1 space probe was launched from Cape Canaveral in September 1977, and is now nearly 12 billion miles from or Sun. In 1979 and 1980, Voyager made close flyby's of both Jupiter and Saturn, respectively.
Sister probe, Voyager 2, lifted-off two weeks before Voyager 1 and headed off in a different direction after first soaring past Jupiter, Saturn, Uranus and Neptune. It is located nearly 10 billion miles from the Sun.
Stone added his team are unsure exactly when the space probe will arrive in the region of "interstellar space free from the influence of our solar bubble".
In defining exactly where the real boundary of the solar system is remains in debate with most scientists, some who say Voyager has not officially left yet.
"What we can say is Voyager 1 is bathed in matter from other stars," Stone said. "What we can't say is what exact discoveries await Voyager's continued journey."
NASA on Thursday also confirmed that to date, the launch and mission operations of both spacecraft have cost the space agency $988 million.
The JPL team states the craft has enough power to continue running through 2020.
It is at this point that the team will slowly begin powering down Voyager's science instruments until the final instrument switch is switched to "off" in 2025.
A few years later, Voyager's engineering data will then go quiet, and earth's ambassador to the stars will sail on quietly upon the ocean of space.
(Charles Atkeison reports on aerospace, science and technology. Follow his updates via Twitter @AbsolutSpaceGuy and on Instagram @BlueAngels_7.)