Can Humanity Stop A Planet-Killing Asteroid?

Key Concepts:

• Asteroid deflection/destruction
• Kinetic impactors (penetrators)
• Nuclear detonation (standoff and subsurface)
• Planet killer comets
• Mission planning and feasibility
• Early Access PC Game: Star Birds

1. The Threat of Asteroids

• The video opens by illustrating the potential devastation of even a moderate-sized asteroid impact, citing a stadium-sized asteroid impact as equivalent to 4,000 Hiroshima bombs.
• Examples of near-miss asteroids are given:
  • Asteroid OK (2019): Discovered one day before grazing Earth.
  • Asteroid MK (Last year): Spotted 13 days before passing closer than the Moon.
• These asteroids would have unleashed the destructive power of 3,000 and 9,000 Hiroshima bombs, respectively.
• The video highlights the lack of a comprehensive plan for dealing with such threats.

2. Traditional Asteroid Deflection Methods and Their Limitations

• Scientists have proposed various methods:
  • Painting the asteroid for solar deflection.
  • Landing thrusters for steering.
  • Using lasers to scorch the asteroid.
  • Crashing spacecraft into the asteroid (kinetic impact).
• The main problem: These methods are akin to "deflecting a cargo ship by throwing a bag of potatoes at it." They require years or decades of advance notice.

3. The "Secret Weakness" of Asteroids: Pulverization

• The video reveals that most asteroids are not solid rocks but "bags of loosely packed gravel" – heaps of pebbles, minerals, and dust.
• This means pulverizing them is a viable strategy.

4. Nuclear Detonation: Initial Attempts and Failures

• Head-on collision: The asteroid destroys the nuke due to its high speed (70,000 km/h).
• Standoff detonation: Exploding the nuke a few tens of meters above the surface (optimal distance for a 100m asteroid) proves ineffective because there is no air in space to carry a shockwave.
• Subsurface detonation (Hollywood route): Landing on the asteroid, drilling, and burying a nuke is theoretically possible but suicidal and impractical due to the difficulty of landing on small, fast-moving asteroids and the slow drilling process in microgravity.

5. The Smart Way: Kinetic Impactors (Penetrators)

• Analogy: Splitting a log with an axe (a dense, shaped tool).
• "Penetrators" are super-dense, ultra-fast, cosmic bullets made of tungsten.
• They are placed in the asteroid's path and rely on the asteroid's high speed for impact.

6. Penetrators: Mission Parameters and Effects

• The mission's longest part is getting to the asteroid in time.
• Destruction must occur far enough from Earth to avoid a concentrated debris impact.
• Target distance: 2 million kilometers away (more than 4 times the distance to the Moon), one day before impact.
• Current rockets can reach this distance in about a week.
• Example: A 2-meter long, 2.5-tonne penetrator.
• Impact: Releases the power of 120 metric tons of TNT, vaporizing rock and melting tungsten, causing the asteroid to fragment into a diffuse cloud.
• The resulting debris would disperse over hundreds of thousands of square kilometers, creating a "mostly harmless show of cosmic fireworks."

7. Planet Killers: A More Extreme Scenario

• Planet killers are vast comets from the outer solar system, traveling at around 140,000 km/h.
• Example: Comet NEOWISE (2020) had the power of 6,000 times all the nuclear bombs on Earth and was discovered just 4 months before its closest approach.
• Simply breaking a planet killer into millions of pieces is insufficient; the fragments would still be massive and numerous enough to cause catastrophic damage.
• Destruction needs to occur much further away (as far as Mars).
• This requires hundreds of thousands of penetrators, necessitating 24,000 super-heavy rockets (humanity currently has only two, and they are not finished).

8. Combining Penetrators and Nuclear Detonation for Planet Killers

• Requires pre-emptive preparation: A rocket like NASA's SLS loaded with necessary equipment, ready to launch.
• Mission: Launch a single rocket to intercept the comet beyond the orbit of Mars.
• Deployment: Deploy 5 massive penetrators in sequence, spaced 2 kilometers apart.
• Astronauts on a one-way trip supervise the process.
• Impact sequence:
  • The comet smashes into the first penetrator (2,000 tons of TNT equivalent).
  • Subsequent penetrators punch into the same spot, creating a tunnel.
  • The final penetrator carries a 300-megaton nuclear warhead (20,000 times more energy than the Hiroshima bomb).
  • The nuke detonates deep within the tunnel, vaporizing the comet from the inside and causing it to fragment.

9. Conclusion

• Deflecting or destroying asteroids, especially planet killers, requires unprecedented planning and precision.
• The technology and knowledge to achieve this exist today, without relying on future sci-fi advancements.

10. Star Birds Game Promotion

• The video concludes with a promotion for the Kurzgesagt's first PC game, Star Birds, available in Early Access on Steam.
• The game involves mining asteroids, building production chains, and unlocking new technologies.
• Developed in collaboration with Toukana Interactive (creators of Dorfromantik).