Protecting the planet: Big Ideas Lab Podcast highlights LLNL’s mission to stop asteroids

In the next two episodes of the Big Ideas Lab Podcast, Lawrence Livermore National Laboratory (LLNL) explores the fascinating and high-stakes world of planetary defense. The episodes explore the science, technology and international collaboration required to detect, track and deflect asteroids that could pose a threat to Earth. Part two is now available on Apple or Spotify. To catch up, you can also find part 1 on Apple or Spotify.

The episodes feature experts in the LLNL’s Planetary Defense Program, who discuss the challenges of protecting Earth from cosmic hazards and the novel techniques being developed to prevent potential asteroid impacts.

“Planetary defense is one of the only natural disasters we have the power to prevent through science and technology,” said Megan Bruck Syal, a physicist who formerly led LLNL’s Planetary Defense Program. “We have the tools, and it’s worth the effort to protect potentially hundreds of thousands, if not millions, of people.”

Listeners will learn about LLNL work to develop high-fidelity models that simulate the atmospheric breakup of the Chelyabinsk meteor explosion in 2013, which injured over 1,500 people in Russia. Alongside the Tunguska event of 1908, which flattened 830 square miles of Siberian forest, these impact events serve as stark reminders of the potential devastation asteroids can cause.

Kinetic impact

The first episode, released this week, highlights LLNL contributions to cutting-edge asteroid detection and deflection efforts, including NASA’s Double Asteroid Redirection Test (DART) mission. In 2022, the DART spacecraft successfully altered the orbit of Dimorphous, a small asteroid moonlet, proving that kinetic impact could be a viable planetary defense strategy.

“The DART mission was a historic milestone,” said Katie Kumamoto, a design physicist who leads the Lab’s Planetary Defense Program. “It demonstrated that we can move an asteroid by hitting it really hard, and even a small change in velocity can make a big difference if we act early enough.”

Nuclear deflection

The second episode explores nuclear deflection, a more extreme option for larger or imminent asteroid threats. Mary Burkey, a staff scientist at LLNL, explains how nuclear devices could be used to either nudge an asteroid off course or break it into smaller, less hazardous fragments.

“Nuclear deflection is a last-resort option,” Burkey said. “It’s reserved for scenarios where time is short or the asteroid is too large for other methods. The key is precision — delivering just enough energy to alter its trajectory without creating dangerous debris.”

International collaboration

The podcast emphasizes the importance of early detection and international collaboration. With tens of millions of asteroids in our solar system, only a fraction have been catalogued, leaving many potential threats untracked. LLNL scientists are working with global partners to improve asteroid detection and response capabilities, including the use of advanced observatories like the Vera Rubin Observatory in Chile.

“Planetary defense is a global effort,” said Bruck Syal. “It requires cooperation across nations to share data, develop technologies, and prepare for coordinated responses. The stakes are too high for any one country to act alone.”

Modeling and simulation

The podcast also addresses the challenges of modeling asteroid behavior, particularly for rubble-pile asteroids — loose collections of rocks and dust held together by gravity. These unpredictable structures pose unique challenges for deflection strategies, requiring high-fidelity simulations to predict their response to kinetic or nuclear interventions.

As the field of planetary defense continues to evolve, LLNL remains at the forefront of research and innovation. Tune in to the latest episodes of the Big Ideas Lab Podcast to explore the science and stories behind planetary defense. For part two, listen on Apple or Spotify. Part one is also available on Apple or Spotify.