MELISSA BLOCK, Host:
The astrophysicist Neil deGrasse Tyson joins us to talk about that impending transition. He directs the Hayden Planetarium at the American Museum of Natural History in New York. Welcome back to the program.
D: Happy to be with you.
BLOCK: This is the farthest any spacecraft has gone by far, right?
D: Mm-hmm.
BLOCK: NASA announced this yesterday, the Voyager 1 will be leaving the region called the heliosheath. What does that mean?
D: Well, this stream of particles doesn't just stop at Earth, it goes out to the outer reaches of space. And you reach a point where particles from the sun are no longer distinguishable from random other particles traveling throughout the galaxy. And that's the realistic edge of the sun's influence out there. And that's where Voyager 1 is approaching.
BLOCK: And once Voyager 1 leaves the sphere of influence of the sun and goes out into interstellar space, what do you think astrophysicists like yourself might be learning from it?
D: And once you're outside the zone, it's not clear whether things will change much for you because you're kind of wandering interstellar space at that point. And so if we do find something different from nothing, then that will be interesting.
BLOCK: Will Voyager 1 still be sending information back once it's crossed into interstellar space?
D: Yes. It has some - while it's not undergoing any kind of propulsion at the moment, it still has a way to generate electricity. And it's that small amount of electricity that it uses to communicate back and forth with us. So there's no reason why we couldn't keep talking to Voyager well into the next decade.
BLOCK: I read this from the former mission design manager of Voyager, calling it the greatest mission of discovery in the history of mankind. What do you think we've learned from Voyager 1 that's so spectacular?
D: And when we think of a world, you think of a place you might want to visit. And so I think of the solar system differently in the era of Voyager than I did before.
BLOCK: Well, Neil deGrasse Tyson, thanks so much.
D: Happy to be with you again.
BLOCK: Astrophysicist Neil deGrasse Tyson directs the Hayden Planetarium at the American Museum of Natural History in New York. He's also author of the book "The Pluto Files: The Rise and Fall of America's Favorite Planet." Transcript provided by NPR, Copyright NPR.