Have you seen our new episode of Planetary Defenders yet? "This Is Not an Exercise," our latest documentary on the scientists who find asteroids before they find us, is now free to watch on our YouTube channel: youtu.be/5b3n-u_0QAI
A stylized graphic showing the arc of a planet, with various arcs above it symbolizing orbits or trajectories, in shades of neon blue and red against a black background. The text "PLANETARY DEFENDERS" is overlaid in the middle.

ALT A stylized graphic showing the arc of a planet, with various arcs above it symbolizing orbits or trajectories, in shades of neon blue and red against a black background. The text "PLANETARY DEFENDERS" is overlaid in the middle.

Oct 14, 2026 · 3:16 PM UTC

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Perhaps the most fascinating thing about planetary defense is that humanity is learning to predict a natural catastrophe before it happens and potentially prevent it. Unlike earthquakes, hazardous asteroids may offer years of warning.
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When a new episode about the Martians?
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Watching the sky for asteroids is good stewardship. Catching a near-Earth object years out gives us time to act instead of just hoping.
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Untold Origins
@Untold0riginsOct 14
In 1908, a rock exploded over Tunguska with roughly 1,000 times the energy of Hiroshima, flattening 2,000 sq km of Siberian forest — and nobody saw it coming. For most of human history, that was the entire planetary defense plan: luck. It took until 2022's DART mission for humanity to finally shove an asteroid back. Quite a journey to get here.
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Theres something comforting about a whole field of people whose job is finding the rocks before the rocks find us. Glad this ones free to watch
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So when 2024 YR4 briefly looked like a potential city-killer, did anyone in the office start measuring the distance to the nearest window? Asking for a friend who just queued the episode.
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On 27 Dec 2004 these people gave Apophis a 1 in 37 chance of hitting Earth in 2029. The same day, two astronomers found it in photos from March and ruled it out. On 13 April 2029 it still passes closer than our TV satellites. Who’s going to watch?
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So, who’s naming the next big asteroid?
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Planetary defense is one of the coolest things NASA does. DART showed a spacecraft can nudge an asteroid when it hit Dimorphos in 2022, and it rode to space on a Falcon 9 from Vandenberg. Adding this one to the watch list.
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Defenders of the Earth?
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bro imagine your job is just don't let space surprise us 😭
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On September 26, 2022, NASA deliberately crashed its DART spacecraft into Dimorphos, an asteroid moonlet. The impact shortened its orbital period around Didymos by about 33 minutes. It was humanity's first successful demonstration of asteroid deflection through kinetic impact.
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That’s nice, but what do we do with threats? How are we capable of handling them?
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Finding dangerous asteroids before they find us sounds like a government program with a very clear job description.
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Lori Sales⚡️
@LoriSS100Oct 15
Planetary Defenders: find asteroids before they find us. Quiet heroes. Who’s watching the full episode tonight? 🛰️
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The people who spot asteroids long before anyone else knows they are there deserve a documentary. Adding this one to tonight's watch list.
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Chưa xem nữa, nghe tên tập "This Is Not an Exercise" thấy hấp dẫn ghê 🌌
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This sounds fascinating. Always good to see scientists working to protect our planet.
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The greatest threat to life on Earth is the Sun. What is NASA doing about that?
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this is not an exercise" is objectively the most terrifying title possible 💀
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Protecting Earth starts with spotting the danger before it gets here, This looks like a fascinating documentary huge respect to the scientists keeping watch over our planet. Definitely worth watching! 🚀👏💯
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lol k
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Por fin una serie de asteroides donde los buenos los ven venir primero 🛡️☄️🚀
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Asteroid hunters are real-life heroes, adding this one to my watch list!
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the line about finding asteroids before they find us is what sold me on watching
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How’s Saturn looking lately? 👀🪐
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Not yet adding it to the watchlist tonight
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Just queued this up. Finding asteroids before they find us is the kind of work that rarely gets enough attention.
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So what happened to the asteroid CEV51C2 ??? I was tracking him and he disappeared from the list; he was on a route very close to earth.
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wont miss it
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Free to watch means free to ignore
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👍🙏❤️
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Humanity will come together to take on this threat and its so cool that we have people keeping an eye out for this
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A timely reminder that planetary defense is real science.
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NASA. Hai visto il nostro nuovo episodio di Planetary Defenders?
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Nice
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