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[Planetary Defense: The Science of Deflecting Asteroids]-[MY ASTEROID IS BLOWING UP!]

Wow in the World · B1 · 2019-04-15

Preschool Enlightenment
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📋 Summary

Planetary Defense: Can We Really Save the World from Asteroids?

In this episode of Wow in the World, hosts Mindy and Guy Raz explore the fascinating and often misunderstood science of planetary defense. Inspired by the dramatic tropes of disaster movies like Armageddon, the duo investigates whether “blowing up” an asteroid is actually a viable solution for protecting Earth.

The Reality of Planetary Defense

During their visit to Armageddon: The Musical, Mindy and Guy Raz discover that NASA actually has a real-world branch called the Planetary Defense Coordination Office. This government agency is tasked with keeping an eye on the night sky to track any asteroids that come within 30 million miles of Earth. While the concept of a mission to "blow up the asteroid" makes for great cinema, the hosts note that real scientists approach the threat with much more nuance.

Why Smashing Asteroids Might Backfire

Referencing a scientific study by Charles L. Murr from Johns Hopkins University, the hosts explain why simply smashing an asteroid into pieces is "about as pointless as a pigeon in pajamas." Through a simulation, the team demonstrates that even if a spacecraft slams into an asteroid and breaks it into millions of harmless-looking pieces, the asteroid's core often remains intact. Due to the gravitational pull—the invisible force that heavy objects in space use to attract smaller objects—the core can actually suck those smashed pieces back in, effectively reassembling itself like "Humpty Dumpty putting himself back together again."

The Gravity Tractor: A Better Approach

Since direct destruction is ineffective, NASA’s playbook offers a more sophisticated method: the Gravity Tractor. The hosts explain that this strategy involves placing a large object, such as a spacecraft, near an asteroid. Over time, the gravitational field of that object can exert a pull on the asteroid, gradually changing its path and steering it away from Earth. This method relies on the steady, long-term application of physics rather than the "smash, bang, boom" approach favored by Hollywood.

Conclusion

By the end of their time-traveling adventure, Mindy and Guy Raz successfully demonstrate the Gravity Tractor principle using their "Expando Pump" to enlarge their Wow Machine, thereby creating enough gravitational pull to nudge a simulated asteroid off a collision course with Earth. While the science of planetary defense is complex and requires years of planning, the episode emphasizes that understanding the laws of gravity is our best hope for preventing a real-life Armageddon.

🎯Key Sentences

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I think I'm stuck.
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I have chills.
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Let's look it up in here.
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Never gets old.
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📝Key Phrases

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music to your ears
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get on with the show
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belly laugh
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out of this world
5
tell me about it
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📖 Transcript

Grownups, Wondery Plus subscribers can listen to Wow in the World early and ad-free right now.
Join Wondery Plus in the Wondery app or Wondery Kids Plus on Apple Podcasts.
Hey, Wowzer fans, Mindy here.
And before we start the show, I gotta let you know that this November, with a special new episode featuring our friends at Circle Round and Terrestrials on Radiolab for Kids,
And don't miss when Elmo from Sesame Street stops by Wow in the World to make us all belly laugh on November 24th.
Oh, but that's not all, Reg.

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