In Quest To Harpoon A Comet, A Spacecraft Stalks Its Prey

Aug 5, 2014
Originally published on August 6, 2014 9:47 am

Tomorrow morning, a European space probe will arrive at a comet with a tongue-twister of a name: Churyumov-Gerasimenko.

Getting there has been proven even trickier than pronouncing it.

The Rosetta spacecraft began its journey way back in March of 2004.

First it swung past Earth to gather speed. Then it catapulted out to Mars, for a boost from that planet's gravity field. Then in 2007, it came back to Earth for another push — then back out to an asteroid, and back to Earth.

And then it traveled way out to deep space, so far out its solar panels couldn't give Rosetta enough power. Mission controllers shut its systems down and from June of 2010 it traveled silently through the darkness toward the comet.

In January, it got in back in touch with Earth.

"I was relieved; everyone was very relieved," says Matt Taylor, the Rosetta project scientist at the European Space Agency. For the past six months, the spacecraft has been putting on the brakes, easing it into the comet's orbit around the sun.

"We've had other cometary missions before — the difference now with Rosetta is, we're going to escort the comet for over a year," Taylor says. "That's going to unlock so much more information."

About what comets are made of, how they interact with the sun. We didn't even know what this comet looked like... until now.

"It's mind-blowing," Taylor says.

People think of comets as dirty snow balls, but this one looks like it's actually two chunks of material stuck together. It's hard to describe... maybe an intergalactic rubber ducky?

"It's start to look a bit more like a boot now though," Taylor says. "I'm reminiscent of the Monopoly boot."

This is really a ground-breaking mission," says Karl Battams, an astronomer at the U.S. Naval Research Laboratory in Washington, D.C. "Pretty much everything you could hope to do on a comet, Rosetta is going to be doing it."

For Battams, the most exciting part comes in November.

"Later this year the Rosetta spacecraft is going to release a lander," he says. This lander is going to float down to the surface of the comet, and attach itself with a kind of spear.

"I mean, not only are they landing on a comet, they're harpooning a comet," he says.

It's an enormously risky mission. Comets are famous for their tails — a spray of dust and water vapor that shoots out as they swing by the sun. But the sun's radiation also makes the comet's nucleus unstable. Rosetta and its lander will have to avoid jets of debris that could shoot out at any time.

Assuming it works, scientists think they will learn an enormous amount from all this scratching and sniffing, because comets are some of the most ancient things in our solar system.

"They're frozen pieces of what the solar system is made of," Battams says. "They're completely untouched, and they really offer a glimpse into how our planet is formed and ultimately how we came to be."

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Transcript

MELISSA BLOCK, HOST:

Tomorrow morning, a European space probe will arrive at a comet - a comet that has a tongue twister of a name. We asked astronomer Karl Battams to say it for us.

KARL BATTAMS: OK. I'm going to take a deep breath. Churyumov-Gerasimenko.

BLOCK: Now, getting to that comet has been way trickier than pronouncing it. But as NPR's Geoff Brumfiel reports, researchers think it'll be worth the trip.

GEOFF BRUMFIEL, BYLINE: At least the comet-hunting spacecraft has an easy name - Rosetta. It launched way back in 2004.

(SOUNDBITE OF ARCHIVED RECORDING)

UNIDENTIFIED MAN 1: Trois, duex, un, top.

(SOUNDBITE OF SPACECRAFT LAUNCHING)

BRUMFIEL: It swarmed past the Earth to gather speed, then catapulted out to Mars for a boost from that planet's gravity. Then it came back to Earth for another push, out to an asteroid, back to Earth and then way out to deep space. For over two years, it traveled silently through the darkness towards the comet. And in January, finally it got back in touch with Earth.

(SOUNDBITE OF ARCHIVED RECORDING)

UNIDENTIFIED WOMAN: Congratulations.

UNIDENTIFIED MAN 2: We made it. We can definitely see the signal from Rosetta. It's up there. You can see from the screen.

PAT TAYLOR: I was relieved. Everyone was very relieved.

BRUMFIEL: Matt Taylor is a project scientist for Rosetta at the European Space Agency. Since January, the spacecraft has been putting on the brakes, easing into the comet's orbit around the sun.

TAYLOR: We have had other cometary missions before. The difference we have now with Rosetta is we're getting in step. We're going to escort the comet for over year. And that's going to unlock so much more information.

BRUMFIEL: About what comets are made of, how they interact with the sun. We didn't even know what this comet looked like until now.

TAYLOR: Now we are really are close. And as we've seen from the recent images, it's mind blowing.

BRUMFIEL: People think of comets as dirty snowballs. But this one actually looks like two chunks of material stuck together. It's kind of hard to describe - maybe an intergalactic rubber ducky?

TAYLOR: I saw the rubber duck immediately. I think I tweeted something along those lines, as well. It starts to look a bit more like a boot now, though - reminiscent of the Monopoly boot. (Laughing).

BRUMFIEL: Karl Battams, the astronomer you heard at the top, studies comets at the U.S. Naval Research Laboratory. He can't wait for Rosetta to get there.

BATTAMS: This is really a groundbreaking mission.

BRUMFIEL: In its year-long journey, the spacecraft is going to do it all.

BATTAMS: Pretty much everything you could hope to do on a comet - Rosetta is going to be doing it.

BRUMFIEL: The best part is going to come in November.

BATTAMS: Later this year - and this is the really super, super cool part of the mission - the Rosetta spacecraft is going to release a lander.

BRUMFIEL: The lander's going to float down to the surface of comet and detach itself with a kind of spear.

BATTAMS: I mean, not only are they landing on a comet, they're harpooning a comet. (Laughing) Not harpooning a whale - we're harpooning a comet, which is fabulous.

BRUMFIEL: Scientists think they could learn an enormous amount from all this scratching and sniffing because comets are some of the most ancient things in our solar system.

BATTAMS: They're frozen pieces of what the solar system is made of, and they're completely untouched. And they really offer us a glimpse into how our planet was formed, and I guess, ultimately, how we came to be.

BRUMFIEL: But we're not quite there yet. Rosetta still needs to fire its thrusters one last time tomorrow morning. Geoff Brumfiel, NPR News. Transcript provided by NPR, Copyright NPR.