Asteroids: Planetary Defense, DART & Cosmic Threats | SPACETIME Full Documentary

How real is the asteroid threat—and what could we do if one was headed for Earth?
In this SPACETIME special, astronaut Prof. Ulrich Walter explains what asteroids and comets are, how scientists discover, track, and assess near-Earth objects, and the tools of planetary defense—from early warning surveys to kinetic impactors (DART-style), gravity tractors, and last-resort options.

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What You’ll See

Asteroids, comets, meteoroids & meteorites—what’s the difference?

Where hazardous objects come from and why their orbits change

How we find them: sky surveys (space- and ground-based) & follow-up tracking

Risk assessment: impact probabilities, size, energy & the Torino Scale

Famous events: Chicxulub, Tunguska, Chelyabinsk—what they teach us

Deflection concepts: kinetic impactor, gravity tractor, and nuclear standoff

What happens if we detect a credible threat—timelines, decisions, and response

Chapters
0:00 Why Asteroids Matter
3:00 Space Rocks 101: Types & Origins
7:20 Finding NEOs: Surveys & Tracking
12:10 Estimating Risk: Size, Speed & Scales
16:40 Lessons from Past Impacts
21:30 Deflecting a Threat: Methods that Work
26:20 Preparing for the Next Close Pass
30:00 What We Still Don’t Know

Details & Keywords
SPACETIME Science Show, Ulrich Walter, asteroids, comets, near-Earth objects, NEOs, planetary defense, DART mission, impact risk, Torino Scale, gravity tractor, kinetic impactor, space surveys, asteroid detection, Chelyabinsk, Tunguska, Chicxulub, space hazards, astronomy documentary

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