Transcript for Historic Mission: First Spacecraft Lands on Comet Twice
Now to that extraordinary moment in space today. A probe landing on a comet, but it wasn't easy. Take a look. This is the problem right here in space. But the comet it was hurtling toward was moving, too. Orbiting at 83,000 miles per hour. The feat has been likened to trying to land on a speeding bullet. Tonight here, the sound coming in from that come element already. What could it reveal? ABC's Clayton Sandell now. Reporter: Today, history was made. 300 million miles away. By the first spacecraft to ever land on a comet. So, we're there and philae is talking to us. Reporter: The landing wasn't perfect. Problems with thrusters and a harpoon system meant Rosetta's philae landing bounced and is now securely anchored to the surface. Maybe, today we didn't just land once, we even landed twice. Reporter: The european space agency says they still don't know what it means for the mission they launched a decade ago. Using Earth and Mars gravity to fling it towards a speeding target going as fast as 83,000 miles per hour. A 4 billion mile journey that required amazing accuracy. Think of it like launching a tennis ball in New York, sending it around the globe 160,000 times, landing it precisely in my hand here in Los Angeles. So, why study a comet? It could be that comet seeded the Earth with the building blocks for life. Reporter: Rosetta may tell us more about this mysterious noise. Scientists call it singing. Energy they think is generated when pieces of the comet slough off into space. Tonight, it's the scientists singing the praises of two small spacecraft, hoping to answer some of our biggest questions. Clayton Sandell, ABC news, los Angeles.
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