Episode Summary
Executive Summary: Neil deGrasse Tyson and Eugene Mirman interview Apollo 9 astronaut Rusty Schweickart about the B612 Foundation’s mission to protect Earth from asteroid impacts. They explain impact risks, deflection politics, detection gaps, mission costs, and why asteroid defense should be treated as a public-safety issue rather than a science program.
Main Topics: B612 Foundation and the asteroid threat (Priority: 5/5): Rusty Schweickart explains how B612 began and why asteroid defense emerged as a serious planetary-protection effort after space experts realized no one was planning for a known hazard. Detection, cataloging, and near-Earth objects (Priority: 5/5): The discussion centers on finding and tracking potentially dangerous asteroids, especially near-Earth objects larger than about 140 meters, and improving orbital precision with dedicated observer missions. Deflection strategies and the deflection dilemma (Priority: 5/5): The hosts and Schweickart explore whether asteroids should be pushed, blown up, or redirected, including the risk that deflecting one threat could shift danger onto another nation or city. Impact physics and disaster severity (Priority: 4/5): They compare airbursts, ocean impacts, and land impacts, using Chelyabinsk and Tunguska to show how different sizes and compositions produce very different damage patterns. Cost and practicality of asteroid defense (Priority: 4/5): Schweickart argues that deflection missions are relatively cheap compared with the economic damage from an impact, making prevention a rational investment. Geopolitics and institutional responsibility (Priority: 5/5): A major theme is who should decide where an asteroid is deflected and which institutions should be legally responsible, with Schweickart urging explicit international and NASA accountability. Comedy, metaphor, and public understanding (Priority: 3/5): Eugene Mirman’s jokes and Tyson’s explanations help translate technical concepts like meteor/meteorite distinctions and calculus-based risk integration into accessible language.
Key Arguments: Asteroid defense is possible if threats are found early enough; the key is detection and timely action rather than last-minute reaction. Deflecting an asteroid is not purely a technical choice because it can move risk from one country to another, requiring international governance. The most dangerous objects are not necessarily the largest, but those with enough kinetic energy to cause regional or civilizational collapse. Ocean impacts can be worse than land impacts for larger asteroids because energy spreads efficiently through water and can create over-the-horizon tsunami effects. Breaking an asteroid apart is not automatically a solution, since the energy remains and fragments may create multiple impact zones. A billion-dollar deflection mission is far cheaper than the hundreds of billions in damage a significant impact could cause. NASA currently lacks formal public-safety responsibility for asteroid defense, so Schweickart argues for a statutory mandate change. Dedicated space-based tracking would greatly improve orbital certainty, reducing uncertainty by about a factor of 50. Small asteroid strikes should be treated like natural disasters, but larger known threats should be actively prevented before impact.
Data Points: Foundation start year: 2002 - B612 Foundation was co-founded by Schweickart, Pete Hut, Ed Liu, and others. Asteroid size threshold for cataloging: 140 meters - B612 aims to discover and catalog at least 90% of asteroids larger than this size. Known asteroid population recovered: Less than 1% - Schweickart says fewer than 1% of million asteroids larger than 40 meters have been identified. Chelyabinsk asteroid size: About 17 meters across - The 2013 Russian airburst came from an asteroid around this size. Chelyabinsk energy: About 20 times Hiroshima - Schweickart compares the airburst’s energy to the atomic bomb dropped on Hiroshima. Chelyabinsk injuries: About 1,500 people - Glass-shard injuries from the shockwave caused widespread but nonfatal harm. Tunguska devastation: 10,000 square kilometers - The 1908 airburst incinerated forest across a large Siberian area. Billion-dollar deflection mission cost: $500 million to $1 billion - Estimated cost for an actual asteroid deflection mission. Impact damage estimate for Apophis: About $400 billion - Estimated damage from a 280-meter asteroid impact scenario. Apophis size: 280 meters - Used as an example of a medium-sized asteroid with catastrophic potential. Apophis close approach: April 13, 2029 - Schweickart highlights this as a valuable test case for observation and planning. Apophis proximity to satellites: Below communication satellite altitude - It will pass close enough to test understanding of its trajectory. Communication satellite altitude: 23,000 miles up - Used as a reference point for Apophis’s close pass. Trajectory accuracy improvement: About 50x better - A spacecraft-mounted transponder/observer mission would greatly reduce uncertainty. Energy scaling in air: Inverse cube - Schweickart explains how blast energy disperses in a three-dimensional atmosphere. Energy scaling in water: Inverse square - Used to explain why larger ocean impacts can propagate danger much farther. Hiroshima bomb altitude: About half a mile up - Tyson explains the detonation altitude chosen to maximize damage. Large unknown impact timing: Once every 300 years - Schweickart says a 30–40 meter object might be deflectable only on that rough frequency, making it a poor weapon. Asteroid shockwave threshold: 20 miles above Earth - Chelyabinsk exploded high in the atmosphere, reducing lethality at ground level. Earth-Moon distance: About a quarter million miles - Used to explain the scale of close approaches. Moon-on-globe analogy: About 30 feet away - Illustrates how far the Moon would be from a schoolroom-sized Earth model. NASA budget share for the program: Less than 0.5% - Schweickart argues asteroid-defense detection would require only a small fraction of NASA’s budget.
Pivotal Quotes: "If you knew about it early enough, yeah, you could do something about it." — Rusty Schweickart: On why early detection is the key to preventing asteroid impacts. "In order to eliminate the risk to everyone, there are nations who will have to accept a temporary increase in their risk in order to enable that elimination of the risk for everyone." — Rusty Schweickart: On the geopolitical challenge of choosing a deflection direction. "What we're doing is clarifying the nature of the decision that somebody is going to have to make... it's got to be the collection, the international collection of nations." — Rusty Schweickart: On why asteroid deflection decisions must be international, not unilateral.
Implications: Asteroid defense is framed as solvable but underdeveloped public safety infrastructure. Better detection, global governance, and clear institutional responsibility could prevent civilization-scale disasters at modest cost.