Heard the joke about deja vu? Several times. Then you've probably heard the news about NASA's Voyager 1 spacecraft leaving the solar system. Its departure has hit the headlines many, many times - only for NASA to change its mind. Over the past decade, the veteran space probe has been in, out and even shaken all about. Last September, though, it looked like this game of space hokey-cokey was finally over. Voyager l's normally cautious project scientist Ed Stone declared that, after 35 years, the probe had left for real. "This is humankind's historic leap into interstellar space." So why has it been so hard to tell if Voyager 1 has crossed the border from the solar system to interstellar space? And can we be sure that it has really made it this time? If the latest results are anything to go by, the story of Voyager 1 is far from over.
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