This artist’s concept (above) puts solar system distances in perspective. The scale bar is in astronomical units, with each set distance beyond 1 AU representing 10 times the previous distance. One AU is the distance from the sun to the Earth, which is about 93 million miles or 150 million kilometers. Neptune, the most distant planet from the sun, is about 30 AU. NASA‘s Voyager 1, humankind’s most distant spacecraft, is around 125 AU. Scientists believe it entered interstellar space, or the space between stars, on Aug. 25, 2012. Image released Sept. 12, 2013.
For NASA, it’s official: Voyager 1 has entered interstellar space. But given the many false alarms over the years, what makes scientists so confident now?
This time, researchers have used several clues about plasma changes around Voyager 1 to determine that it entered interstellar space around Aug. 25, 2012. NASA announced that Voyager 1 has arrived in interstellar spaceon Thursday (Sept. 12).
“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 Voyager Project Scientist Ed Stone of the California Institute of Technology in Pasadena, in a statement.