Planetary Defense (Part 2)

Summary

Big Ideas Lab: Planetary Defense (Part 2) – A Detailed Summary

Released on February 11, 2025 by Mission.org

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Introduction to Planetary Defense

In the second installment of the "Planetary Defense" series, the Big Ideas Lab podcast delves into humanity's most daring strategy to protect Earth from devastating asteroid impacts: nuclear deflection. The episode paints a vivid picture of an asteroid threat, highlighting the real dangers posed by celestial objects and the critical need for effective defense mechanisms.

Understanding the Asteroid Threat

The episode begins with a gripping narrative that underscores the potential devastation a large asteroid could inflict upon Earth. Referencing the 2013 Chelyabinsk event, where a house-sized asteroid entered Earth's atmosphere at over 40,000 miles per hour, exploding with the force of 30 Hiroshima bombs and injuring over 1,500 people, the podcast sets the stage for discussing more significant threats.

Cody Raskin, a design physicist at Lawrence Livermore National Laboratory, explains:

"Planetary Defense is tasked with coming up with scientific applications with the goal of deflecting asteroids that might hit the Earth at some time in the future. There are a lot of Earth crossing asteroids. Not all of them have been found or detected, and the properties of these asteroids are very unknown at this point." [04:44]

Raskin further elaborates on the varying sizes and compositions of asteroids:

"The most common size is about somewhere between the size of a car and the size of an office room. Something the size of a car doesn't pose very much of a threat because it would burn up in the atmosphere. Something larger than that can actually survive the entry into the atmosphere and hit the ground." [05:27]

Nuclear Deflection Strategies

As asteroid threats become more imminent and substantial, conventional methods like kinetic impact may fall short. This is where nuclear deflection emerges as a potent, albeit extreme, strategy. The podcast introduces Mary Burke, a staff scientist at Lawrence Livermore National Laboratory, who provides an in-depth look at the nuclear mitigation options available.

Nuclear mitigation involves the use of nuclear devices to alter an asteroid's trajectory or composition. Burke outlines two primary techniques: standoff detonation and surface detonation.

"If you want to give it a gentle push, you can move your device far away and detonate it there. If it's small enough and there's a chance that you could actually blow it to bits, you can bring your device really close and detonate it there and blow it into all tons of tiny, fast moving particles that will go out in every direction and all of them will miss Earth if you do it a couple of months in advance." [08:22]

Standoff detonation involves detonating a nuclear device at a distance from the asteroid, vaporizing a portion of its surface and creating a reactive force that alters its path. This method minimizes the risk of producing large fragments that could still pose a threat. Conversely, surface detonation places the device directly on or near the asteroid, delivering a more concentrated energy transfer aimed at breaking the asteroid into smaller, dispersed pieces.

Modeling the Asteroid Response

Precision is paramount in nuclear deflection, necessitating detailed modeling to predict how an asteroid will react to a nuclear blast. Mike Owen, a computational physicist at Lawrence Livermore National Laboratory, discusses the complexities involved in this process.

Owen highlights the fragile nature of rubble pile asteroids:

"Asteroids are mostly built up of smaller rocks that happen to loosely get together due to gravity pulling them together. But they are really loose. They can come apart if you just spin them too fast." [11:39]

The unpredictability of these loosely bound structures complicates the modeling efforts. Accurate simulations require extensive computational resources to solve complex equations that describe the asteroid's behavior under explosive forces.

"We try to describe it all with mathematics... Those equations are often very, very complex. And sometimes we can't solve them on paper to get the entire answer." [12:39]

International and Political Challenges

Deploying a nuclear device for planetary defense isn't just a technical challenge—it also intersects with significant global political concerns. Mary Burke addresses the intricacies of international treaties that govern space and nuclear activities.

"The nuclear option is tricky because we live in a bit of a tense world right now. And a few decades ago, we all signed a treaty saying we were not going to do nuclear tests in space. A lot of countries signed on to that. The current state of world peace rests on everyone keeping to that agreement." [14:06]

Burke references the Outer Space Treaty of 1967 and the Comprehensive Nuclear Test Ban Treaty of the mid-1990s, which prohibit the use of nuclear explosions in space. These agreements were established to prevent the militarization of space and maintain global security. However, using nuclear deflection as a defensive measure against asteroids may require nations to navigate these complex legal frameworks, potentially challenging the stability these treaties aim to preserve.

Future of Planetary Defense

The episode concludes by emphasizing the multifaceted nature of planetary defense, which encompasses technological innovation, strategic planning, and international collaboration. The future relies on enhancing our detection capabilities, refining modeling techniques, and fostering global cooperation to address asteroid threats effectively.

Cody Raskin offers a poignant analogy:

"I think a good analogy is an asteroid that's going to hit the earth. It has a bus ticket and an appointment. And if the bus is five minutes late, it doesn't make its appointment. And so we're just trying to delay the bus a little bit." [15:29]

He underscores the urgency and precision required in deflection efforts, where every second counts in altering the asteroid's trajectory to avert disaster.

Mary Burke adds:

"Everyone's heard of the dinosaurs. Everyone's heard of what happened to them. And everyone assumes, yes, because we have advanced technology that won't happen to us. We have all of these satellites. But it's a work in progress." [15:51]

Conclusion

"Planetary Defense (Part 2)" provides a comprehensive exploration of the potential and challenges of using nuclear energy to defend Earth from asteroid impacts. Through expert insights from scientists at Lawrence Livermore National Laboratory, the episode highlights the scientific, technical, and political hurdles that must be overcome to implement such a strategy successfully. While the path forward is complex, the dedication and innovation of the scientific community offer hope that humanity can safeguard its future against these cosmic threats.

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Notable Quotes:

• Cody Raskin [04:44]: "Planetary Defense is tasked with coming up with scientific applications with the goal of deflecting asteroids that might hit the Earth at some time in the future."
• Mary Burke [08:22]: "If you want to give it a gentle push, you can move your device far away and detonate it there... All of them will miss Earth if you do it a couple of months in advance."
• Mike Owen [11:39]: "Asteroids are mostly built up of smaller rocks that happen to loosely get together due to gravity pulling them together. But they are really loose."
• Cody Raskin [15:29]: "We're just trying to delay the bus a little bit."
• Mary Burke [15:51]: "Everyone assumes, yes, because we have advanced technology that won't happen to us. We have all of these satellites. But it's a work in progress."

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Note: This summary excludes promotional segments related to job openings and other non-content sections to focus solely on the episode's informative segments on planetary defense.

Transcript

[Narrator]

You were driving home from work on a quiet evening when the sky erupted in a flash of light. You gripped the wheel, your heart pounding. The intense, searing brightness forced you to shield your eyes and pull over, instinctively ducking your head and covering your ears. Then it hit. A deafening explosion shook your car, shattering windows and nearby buildings as the air seemed vibrate with an immense, unrelenting force. Everything went still. You tried to process what just happened. Was it a plane crash? A bomb? The truth is even more extraordinary. A massive object from space had just entered Earth's atmosphere. This is not as far fetched as it sounds. In 2013, in Chelyabinsk, Russia, a house sized asteroid raced through the atmosphere at over 40,000 miles per hour, exploding with the force of 30 Hiroshima bombs. It injured over 1500 people and caused damage across miles of the city. And that was a small one. Now imagine an asteroid the size of a city heading toward us as its path intersects with Earth's orbit. Scientists have limited options, and one of those options, the most extreme, is nuclear deflection. This is the second episode in our Planetary Defense series. Today we dive into the boldest strategy humanity has for planetary defense. What are the risks of using nuclear energy to stop an asteroid? And what does it take to protect our planet from a force of nature that's been around for billions of years? Lets explore the science and stories behind the ultimate planetary defense challenge. Stopping an Asteroid with Nuclear Energy welcome to the Big Ideas Lab. Your weekly exploration inside Lawrence Livermore National Laboratory. Hear untold stories, meet boundary pushing pioneers and get unparalleled access inside the gates. From national security challenges to computing revolutions to discover the innovations that are shaping tomorrow. Today, Lawrence Livermore National Laboratory is opening its doors to a new wave of talent. If you're driven by curiosity and a desire to solve complex challenges, the lab has a job opening for you. Currently, there are 139 open positions. These include opportunities in science, engineering, business administration and the skilled trades. From enhancing national security to pioneering new energy sources and advancing scientific frontiers, Lawrence Livermore National Laboratory is where you can make your mark on the world. Today's Open roles lead power grid engineer, laser modeling physicist, Postdoctoral researcher, OCEC program leader and chief data architect. But the list doesn't end there. Explore all available [e-mail] careers. Each opportunity comes with a comprehensive benefits package tailored to your lifestyle and future. Join a workplace that champions professional growth, fosters collaboration, inspires innovation and and drives the pursuit of excellence. If you are ready to contribute to work that matters, visit llnl.govcareers to explore all the current job listings. That's llnl.govcareers your expertise could very well be the highlight of our next podcast interview. Don't wait Asteroids might seem like distant curiosities, tiny specks floating in space, but their orbits often bring them uncomfortably close to Earth. And close in space terms means within roughly 28 million miles of Earth's orbit. And while many asteroids pass harmlessly, a select few pose a real danger. Cody Raskin is a design physicist at Lawrence Livermore National Laboratory.

[Cody Raskin]

Planetary Defense is tasked with coming up with scientific applications with the goal of deflecting asteroids that might hit the Earth at some time in the future. There are a lot of Earth crossing asteroids. Not all of them have been found or detected, and the properties of these asteroids are very unknown at this point. So we work on ways to constrain the properties of those asteroids and different ways that you could try to deflect them in case one of them was going to hit the Earth.

[Narrator]

Asteroids come in different sizes, shapes, and compositions. Some are small enough to burn up harmlessly in the atmosphere, while others, which can be the size of a city, have the potential to cause devastation.

[Cody Raskin]

The most common size is about somewhere between the size of a car and the size of an office room. Something the size of a car doesn't pose very much of a threat because because it would burn up in the atmosphere. Something larger than that can actually survive the entry into the atmosphere and hit the ground. And the larger it is, obviously the greater the impact on the ground, the greater the destruction. These are very much larger ones, hundreds of meters across. They can cause destruction of an entire city.

[Narrator]

The strategy for deflecting an asteroid depends on its size, speed, and distance from Earth. For smaller threats, kinetic impact, or essentially crashing a spacecraft into the asteroid may be enough to nudge a space rock off course. Tune into our previous episode to learn all about that process. But for larger or more imminent threats, scientists need something even more powerful. That's where nuclear deflection comes in.

[Mary Burke]

I work on the planetary defense team, and my job is specifically to explore the nuclear mitigation option.

[Narrator]

That's Mary Burke, a staff scientist at Lawrence Livermore National Laboratory. Nuclear mitigation relies on nuclear devices to alter an asteroid's trajectory or composition. This approach is typically used in extreme scenarios where time is limited or the asteroid size and makeup render other methods ineffective. The immense energy of a nuclear detonation can either redirect the asteroid away from Earth or break it into smaller, less hazardous pieces. The two techniques for nuclear mitigation are standoff detonation and surface detonation. Standoff detonation involves detonating a nuclear device at a distance from the asteroid.

[Cody Raskin]

You could actually detonate a nuclear device near the asteroid and deposit enough of its energy into the material of the asteroid such that it would blow off.

[Narrator]

The resulting burst of heat and radiation vaporizes part of the asteroid's surface, creating a rocket effect as the expelled material pushes the asteroid onto a new path. This method minimizes the risk of creating large, dangerous fragments. The second approach, surface detonation, places the device directly on or near the asteroid's surface. This delivers a more powerful energy transfer and would typically be used to intentionally disrupt the asteroid, breaking it into many well dispersed fragments.

[Mary Burke]

If you want to give it a gentle push, you can move your device far away and detonate it there. If it's small enough and there's a chance that you could actually like blow it to bits, you can bring your device really close and detonate it there and blow it into all tons of tiny, fast moving particles that will go out in every direction and all of them will miss Earth if you do it a couple of months in advance.

[Narrator]

Timing is critical in any scenario involving an asteroid on a collision course with Earth. The defense strategy must be carried out within the window between detecting the threat and its projected impact.

[Mary Burke]

It takes about three years to build a spacecraft to do a flyby mission in deep space.

[Narrator]

Building a spacecraft for a deep space mission requires years of meticulous planning, engineering, and testing. As soon as a potential asteroid threat is identified, those three years become a critical part of the response window. The complexity lies not just in constructing the spacecraft itself, but also in integrating specialized instruments, ensuring reliable propulsion systems, and running rigorous tests to simulate the extreme conditions of deep space. So how does nuclear deflection actually work? Lawrence Livermore National Laboratory invites you to join a diverse team of professionals the lab is currently hiring for a lead power grid engineer, a laser modeling physicist, postdoctoral researcher, an OCEC program leader, a chief data architect, and 139 other positions for scientists, engineers, IT experts, administrative and business professionals, welders, and more At Lawrence Livermore National Laboratory. Your contributions are not just jobs. They're a chance to make an impact. From strengthening US Security to leading the charge in revolutionary energy solutions and expanding the boundaries of scientific knowledge. The lab values collaboration, innovation and and excellence, offering a supportive workspace and comprehensive benefits to ensure your well being and secure your future. Seize the opportunity to help solve something monumental. Dive into the wide variety of job [e-mail] careers. This is your chance to join a team dedicated to a mission that matters. That's llnl. Your expertise might just be the spotlight in our next podcast interview. Don't delay. Something's not right. Too much time has gone by. In Hollywood. Heroes detonate bombs directly onto the asteroid. Zero barriers about to be breached. One minute. Come on. Press that button. It reads Bracey.

[Mike Owen]

Press it.

[Mary Burke]

We have detonation, verbic detonation.

[Narrator]

But in reality, scientists back on Earth in a lab are the real heroes. They aim for a controlled, precise explosion at a distance, delivering just enough energy to alter the asteroid's trajectory. Here's Mike Owen. He's a computational physicist at Lawrence Livermore National Laboratory.

[Mike Owen]

Asteroids are not simple things. They're mostly built up of smaller rocks that happen to loosely get together due to gravity pulling them together. But they are really loose. They can come apart if you just spin them too fast. And that happens to a lot of them in the solar system. They will get spun up by just interactions with basically heating from the sun, and they'll spin up, and then they'll start to throw off pieces of themselves. And that's why sometimes asteroids have smaller asteroids as moons.

[Narrator]

Nuclear deflection is about precision, and understanding how the asteroid will respond to the blast requires detailed modeling of everything the asteroid shape, composition, and even the direction and force of the explosion.

[Mike Owen]

You don't have to hit them very hard to break them up. They're very fragile. Actually, you hit them hard enough so that, you know, you break it up really robustly. So it just flies to bits, and all the pieces fly everywhere. And most of it would never hit Earth because you disperse it. It's that middle ground you got to worry about where you just barely break it up. That's what you don't want.

[Narrator]

Here's where modeling comes in. Using complex equations and simulations to predict how an asteroid will respond to different levels of force.

[Mike Owen]

We try to describe it all with mathematics. So we try to write equations to describe things we're interested in, like the way a ship might move through the solar system following gravity, or the way gases or fluids or solids will react if you do something to them or hit them or they collide and come together. Since we have all these equations that we use to try to understand these things, those equations are often very, very complex. And sometimes we can't solve them on paper to get the entire answer.

[Narrator]

Solving these equations often requires computational models to simulate what happens over time. Then testing the accuracy of those models and turning them into actionable science.

[Mike Owen]

It's not science if we can't measure it. So we have to be able to make a prediction that we can then go and do an experiment. And somehow say, did this happen according to the model I think is true, or did it not happen?

[Narrator]

One of the biggest challenges. Lies in accounting for the unpredictable nature of rubble pile asteroids. These loosely bound collections of debris. Can absorb or dissipate energy in unexpected ways, Making it harder to predict their response To a nuclear detonation.

[Mary Burke]

It's just a whole bunch of rocks Floating together in space, and that's a rubble pile asteroid.

[Narrator]

Rubble pile asteroids highlight the diversity of threats. That planetary defense must address. Beyond the technical challenges. Deploying a nuclear device in space. Raises significant global concerns. Rooted in global politics. And the fragile balance of international agreements.

[Mary Burke]

The nuclear option is tricky because we live in a bit of a tense world right now. And a few decades ago, we all signed a treaty. That said we were not going to do nuclear tests in space. A lot of countries signed on to that. The current state of world peace Rests on everyone keeping to that agreement.

[Narrator]

Mary is referring to the outer Space Treaty of 1967. And the Comprehensive Nuclear Test Ban Treaty from the mid-1990s. Key agreements that form the backbone of international space and nuclear nuclear diplomacy. These treaties were created to prevent the militarization of space. And prohibit nuclear explosions, including tests in Earth's atmosphere, Underwater or in outer space. These agreements maintain peace and global security. Yet also pose a significant challenge for planetary defense. Using nuclear deflection to save Earth from an asteroid. Likely requires nations to navigate. Complex legal and political hurdles, Potentially breaking the agreements that have preserved stability for decades. The concept of nuclear deflection. Is both a testament to human ingenuity. And a humbling reminder of our planet's vulnerabilities. When an asteroid is heading towards Earth's atmosphere, Every second matters.

[Cody Raskin]

I think a good analogy Is an asteroid that's going to hit the earth. It has a bus ticket and an appointment. And if the bus is five minutes late, it doesn't make its appointment. And so we're just trying to delay the bus a little bit.

[Narrator]

The challenge is about technology, strategy, and a global commitment to planetary defense. For all the progress made, we're still building foundations.

[Mary Burke]

Everyone's heard of the dinosaurs. Everyone's heard of what happened to them. And everyone assumes, yes, because we have advanced technology that won't happen to us. We have all of these satellites. But it's a work in progress.

[Narrator]

The future of planetary defense Depends on improving our ability to detect potential threats, Refining our modeling techniques to predict outcomes with greater precision and fostering the kind of international cooperation that transcends borders. The universe is vast and unpredictable. Humanity's capacity for innovation gives us a fighting chance. Whether through kinetic impact or nuclear deflection, the mission is clear Safeguard our planet and secure the survival of life on Earth. Lawrence Livermore National Laboratory is opening its doors to a new wave of talent. Whether you're a scientist, an IT professional, a welder, an administrative or business professional, or an engineer, Lawrence Livermore National Laboratory has an opportunity for you. From enhancing national security to pioneering new energy sources and advancing scientific frontiers, Lawrence Livermore National Laboratory is where you can make your mark on the world. Lawrence Livermore National Laboratory's culture is rooted rooted in collaboration, innovation and the pursuit of excellence. We offer a work environment that supports your professional growth and a benefits package that looks after your well being and future. Are you ready to contribute to work that matters? Visit llnl.govcareers to explore current job openings and learn more about the application process. Don't miss the chance to be a part of a mission driven team working on projects that make the impossible possible. Visit llnl.govcareers now to view the current job listings. Remember, that's llnl.govcareers. your expertise could be the highlight of our next podcast interview. Don't wait, explore the possibilities today. Foreign thank you for tuning in to Big Ideas Lab. If you loved what you heard, please let us know by leaving a rating and review. And if you haven't already, don't forget to hit the Follow or Subscribe button in your podcast app to keep up with our latest episode. Thanks for listening.