DON GONYEA, HOST:
We've got a Kosmos 482 coming right up. No, no, it is not a cocktail. It is a spacecraft. The Soviet-era planetary probe, Kosmos 482, was sent from Earth on a mission to Venus in the year 1972. However, technical malfunctions ensued. It went off course, and the spacecraft never made it out of Earth's orbit. It has now been stuck in that orbit, circling and circling and circling for over 50 years. But now, it seems like Kosmos 482 might finally be coming home, as scientists predict it will plunge back to Earth sometime this month. Jonathan McDowell is an astrophysicist at the Harvard-Smithsonian Center for Astrophysics. He is here to help us make sense of this fascinating story. Welcome.
JONATHAN MCDOWELL: Thank you. Yes. It's a fun, little event.
GONYEA: So describe the spacecraft - how big is it, what's it look like, all of that.
MCDOWELL: Right. It's a sphere about 3 feet across. It's about half a ton, so like the weight of a small car. And it was designed to survive entry into the hellish Venusian atmosphere. But the rocket stage malfunctioned, and so it didn't have enough speed to escape Earth's gravity. And so it ended up in an orbit that had its initial low point of only about 150 miles, and the high point was as high as 6,000 miles. And so every hour or so, it would loop around the Earth going down to 150, up to 6,000. And every time it goes down, it plows through the outer edge of Earth's atmosphere, slows down a tiny little bit, so it doesn't go quite as high the next time. But it took 50 years to bleed off enough height to bring it down now to being on the edge of reentry.
GONYEA: OK, the way you describe that - to bleed off enough height - it's so, so gradual.
MCDOWELL: That's right. And now it's in its final death plunge.
GONYEA: So people listening are probably thinking to themselves, OK, we're always hearing about satellite X, Y or Z falling out of orbit, burning up in the atmosphere before they hit the ground, and that's that. Will that be the case with Kosmos 482?
MCDOWELL: Well, because it has a heat shield and it was designed to survive the rigors of Venus' atmosphere, what I expect is instead of burning up and melting, it will reenter essentially undamaged. And so somewhere on Earth, this half ton sphere will fall out of the sky at a couple hundred miles an hour. And most likely it'll be over the ocean, and no one will ever know.
GONYEA: Overwhelmingly likely that it hits a body of water, one of the oceans or some unpopulated space, some unpopulated area, but you never know.
MCDOWELL: You never know. There's a not trivial chance that it could hit somewhere where it damages property. And there's a small chance - but it's like one in thousands - that it could hurt somebody (ph).
GONYEA: Kosmos 482 - it was supposed to go to Venus. It never made it. It's coming back home. Who knows where? That's Jonathan McDowell, astrophysicist at the Smithsonian Observatory located at Harvard University. Thanks, Jonathan, and we've got our hard hats handy here.
MCDOWELL: Absolutely. I'm ready to duck.
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