Asteroooooid De-FENSE!

October 13, 2026

AI Summary

5 min read

Asteroids Are Coming, But We Might Actually Be Ready

In December 2022 alone, five asteroids appeared on NASA's close approaches list, two of them roughly the size of commercial jets. Earlier that same year, a rock two and a half times the height of the Empire State Building came within 1.2 million miles of Earth—its closest pass in 200 years. That sounds like a comfortable distance until you learn it's closer than some satellites in orbit. And then there's Apophis: 375 meters across, due to arrive on April 13, 2029, within 20,000 miles of our planet. NASA says there's basically no chance of it hitting Earth for the next hundred years. They added that last part kind of quietly.

What Asteroids Actually Are

Asteroids are small rocky bodies, either ancient pieces of the early universe that never coalesced into planets or smashed remnants of early planets that did. Most of the 1.8 million known asteroids sit in the belt between Mars and Jupiter, trapped there by Jupiter's immense gravity—so strong it can break things apart just by orbiting near them. The largest, Ceres, discovered by Italian astronomer Giuseppe Piazzi in 1801, is 620 miles across and makes up one-third of the total mass of the entire asteroid belt.

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What you'll learn

1 (01:03) **Asteroids: The Basics** - Josh and Chuck introduce the topic, explaining that asteroids are ancient rocky bodies, either leftover planet-building material or smashed remnants of early planets.
2 (03:55) **How We Found Them: From Bode to Ceres** - The history of asteroid discovery begins in the 1770s with a mathematical prediction of a missing planet between Mars and Jupiter.
3 (06:14) **The Threat: Close Approaches and Apophis** - NASA monitors potentially hazardous asteroids, including the famous Apophis, which will come extremely close to Earth in 2029.
4 (09:04) **Defining the Danger: PHAs and Extinction-Class Rocks** - The hosts break down the classification system for threatening asteroids, from "potentially hazardous" to "extinction class."
5 (15:03) **What Would Happen? The Scale of Impact** - The hosts illustrate the destructive power of asteroids by comparing their size to familiar objects and historical events.
6 (18:14) **Case Study: The Chicxulub Impactor** - The hosts detail the asteroid strike that killed the dinosaurs 66 million years ago, focusing on the chain reaction of global destruction.
7 (23:57) **The Silver Lining and the New Threat** - The extinction that wiped out the dinosaurs allowed mammals to diversify, leading to humans, who now face a similar existential threat.

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Show Notes

There’s no question that millions of asteroids are circling the Earth at incredible speed and every one of them is just dying to get a chance to smoosh our planet and wipe out life in the universe once and for all. But Earth has an ace up its sleeve: Us!

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