Space fans will have to hold off on popping the champagne cork. After the American Geophysical Union declared this morning that Voyager 1 had achieved the mind-boggling feat of leaving our solar system, NASA threw a wet blanket on the party, at least temporarily, reports Time. “It is the consensus of the Voyager science team that Voyager 1 has not yet left the solar system or reached interstellar space," says project scientist Edward Stone. The AGU later toned down its press release.
The spacecraft, launched in 1977, is at the very least close to the edge of the solar system, but NASA says it needs more data, specifically the detection of a "change in the direction of the magnetic field," to declare Voyager the first interstellar traveler, reports Space.com. The fact that it's in such new territory is what makes verification tricky. "It is actually a very difficult problem identifying exactly where the solar system ends and interstellar space begins," writes Adam Mann at Wired. (Read more Voyager 1 stories.)