Date: February 14, 2011
Title: Stardust: A Love Story
Podcaster: Kate Becker
Links: SpaceCraft science writing: www.spacecrafty.com
Inside NOVA: http://www.pbs.org/wgbh/nova/insidenova/author/kathryn-becker/
The Daily Camera: www.dailycamera.com
Social media: http://www.facebook.com/katembecker, www.twitter.com/kmbecker
Description: The Stardust spacecraft’s Valentine’s Day rendezvous with comet Tempel 1.
Bio: Kate Becker is a story researcher for NOVA, the public television science documentary series, and an astronomy columnist for the Daily Camera in Boulder, Colorado. Kate studied physics at Oberlin College and astronomy at Cornell University, and she’s had the good fortune to observe with the Arecibo Observatory in Puerto Rico and the Very Large Array in New Mexico—two of the very best places on this pale blue dot of a planet, if you ask her. Kate lives in Brookline, Massachusetts.
Today’s sponsor: This episode of “365 Days of Astronomy” is sponsored by Ian Harnett.
Transcript:
So, it’s Valentine’s Day, and that means that, even though this is an astronomy podcast, you get to hear a love story. It’s a story about second chances—our characters have some scars—and about a long distance relationship in the extreme. So put on some soft music, curl up with your favorite person—or your favorite box of chocolates—and let’s get started.
Our story starts more than ten years ago, with a spacecraft named Stardust. Stardust wasn’t much to look at. A couple of solar panels flanking a dust analyzer, a navigation camera, and a bank of thrusters. But Stardust had a mission no other spacecraft had ever attempted: To journey out into space, meet a beautiful comet, and get up close and personal—so close that Stardust would be able to lock up dust particles from the comet’s heart. Then, Stardust would send those dust particles back to Earth for analysis.
Stardust’s mission was to kiss and tell.
In February 1999, Stardust was launched into space from Cape Canaveral. For five lonesome years, Stardust pursued its comet, making lonely loops around the Sun while it bided time, collecting interstellar dust. And then, finally, after almost two billion miles of wandering, Stardust spotted its comet.
The comet’s name was Wild 2. Wild 2 wasn’t so young—actually, she was about 4.5 billion years old. But that was part of the attraction. Wild 2, like other comets, had been born at the same time as our solar system.
But Wild 2 had spent most of her life on the outskirts of the solar system, never venturing too close to the Sun. The Sun, for comets and for humans, is a double-edged sword: Come too close and, sure, you’ll have a nice glow for a while–but stay too long, and you’ll start to lose your youthful good looks—or, if you’re a comet, you’ll start to lose your volatile compounds.
But everything changed for Wild 2 when, in 1974, she ventured too close to Jupiter. Jupiter’s gravity pulled Wild 2 into a new, tighter orbit. In this new orbit, Wild 2 was an exotic anomaly—a pristine face among so many other haggard ones. But the cosmic clock was ticking. With every trip past the Sun, Wild 2 lost a little bit of the material that made her so scientifically beguiling.
On January 2, 2004, Stardust appeared on the sunlit side of Wild 2. They locked eyes—well, Stardust took photos—and Stardust flipped open its particle catcher—a sort of cometary locket—to capture particles from the heart of Wild 2. For ten hours, Stardust was pelted by debris as it passed through the coma of Wild 2.
At their closest, Wild 2 and Stardust passed within 150 miles of each other. Stardust snapped some photos to remember Wild 2 by. And then, just like that, it was over. Stardust and Wild 2 went their separate ways. Their brief encounter—their only respite from the near-perfect isolation of space—was over.
Stardust delivered its samples back to Earth in 2006, and those samples were full of scientific surprises. In addition to icy grains that formed at the edge of the solar system, Wild 2 contained rocky material that had been cooked under the white-hot flame of the young Sun. Scientists also spotted glycine, an amino acid, on Wild 2. Perhaps comets like Wild 2 delivered these biological building blocks to Earth long before life took hold on our planet.
And that could have been the end of the story: Mission complete. One spacecraft, one perfect encounter.
But meanwhile, another comet, Tempel 1, was having a rendezvous with another NASA spacecraft, Deep Impact. But this was no mere kiss-and-tell: this was something more dangerous. In 2005, on the fourth of July, Deep Impact sent an 800-pound copper projectile slamming into Tempel 1. Why? Curiosity. Just after impact, the spacecraft went flying through the plume of debris it had let loose.
And, it invited all its friends to watch. Hubble, Chandra, Spitzer, Rosetta—they all took pictures of the destruction, looking for clues to what exactly was inside of Tempel 1. And then Deep Impact continued on its way. Tempel 1 did, too, but with a fresh scar on its surface.
Now, take a spacecraft with just enough juice left for one more fling—that’s Stardust—and a comet, a little wounded and worse for wear—that’s Tempel 1—put them together, and what do you have? A match made in heaven. (Or, a match made at Cornell, where principal investigator Joe Veverka works.) And right now, Stardust and Tempel 1 are on course to meet each other today—yes, that’s February 14, Valentine’s day.
No, Stardust can’t capture dust anymore—that ship has sailed—but it can still take images and data. And, no, Tempel 1 isn’t pristine like Wild 2. But that’s part of what makes it such a great match. Stardust has a unique opportunity—a chance to see how the comet has changed in the six years since it encountered Deep Impact. What will the scar look like now? How much will Tempel 1 have been aged by its latest close passage of the Sun?
Today, Stardust and Tempel 1 will pass within 100 miles of each other. Their rendezvous will take place at a relative speed of more than 13,000 miles per hour. No, it might not be your ideal Valentine’s Day date. But it’s nice to know that, in the vast emptiness of space, even a lonely spacecraft can get a second chance.
End of podcast:
365 Days of Astronomy
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