NASA says its Voyager 2 probe has become the second human-made object to fly into interstellar space — six years after its twin, Voyager 1, became the first.
Based on readings from its onboard instruments, the mission’s scientists have determined that Voyager 2 has left the solar system’s heliosphere, a protective bubble of particles and magnetic fields created by the sun. The spacecraft is now journeying in a region where the cold, dense interstellar medium takes the place of the tenuous, hot solar wind — more than 11 billion miles from Earth.
The milestone came more than 41 years after Voyager 2’s launch in 1977 on what was then a grand interplanetary mission, and is now a grand interstellar mission. During the 1970s and 1980s, Voyager 2 took on a “Grand Tour” with close flybys of Jupiter, Saturn, Uranus and Neptune, while Voyager 1 took a different course that featured a close-up of the Saturnian moon Titan.
Scientists discussed the mission’s status today in conjunction with this week’s American Geophysical Union meeting in Washington, D.C.