MELISSA BLOCK, host:
From NPR News, this is ALL THINGS CONSIDERED. I'm Melissa Block.
MICHELE NORRIS, host:
And I'm Michele Norris.
Now news from a place no one has gone before.
Mr. EDWARD C. STONE (NASA; California Institute of Technology): Voyager 1 has entered the final outermost layer of the bubble that's around the sun. So it's now in its final lap in its race to the edge of interstellar space.
BLOCK: What NASA's Ed Stone is saying is that Voyager 1 is well on its way to leaving the solar system. It's the farthest anyone has ever sent a man-made object.
NORRIS: Voyager 1 was launched in the summer of 1977. It's now moving away from home at about a million miles a day.
BLOCK: Its sister, Voyager 2, is not far behind.
NORRIS: Ed Stone says there's no immediate danger of Voyager 1 running out of power as it goes even farther from Earth.
Mr. STONE: We're very fortunate the Voyager spacecraft have radioisotope thermoelectric generators, which means they're nuclear-powered. It's a thermal heat source. We expect to have enough electricity to continue sending signals home till about 2020.
BLOCK: Voyager 1's radio signals take 13 hours to reach Earth.
NORRIS: Right now it's moved beyond the reach of solar winds, and it's headed toward deep space. But NASA's Ed Stone says it will take 10 years to get there and even longer before it might arrive at another solar system.
Mr. STONE: Before we get closer to another star than we are to our sun, it's perhaps another 40,000 years. Even though we're moving a million miles per day, that's still a small speed compared to the distance between stars.
NORRIS: NASA's Ed Stone talking about Voyager 1 and its journey out of our solar system. Transcript provided by NPR, Copyright NPR.
