Bold opening: Deflecting asteroids isn’t just a sci‑fi dream—it’s a real, high-stakes engineering challenge we must get right the first time. And this is where the conversation gets truly important.
Science fiction became science fact in 2022, when NASA’s DART mission marked a historic milestone by attempting to nudge an asteroid off its course. That test laid the groundwork for a planetary defense system capable of someday shielding Earth from a disastrous asteroid impact. Yet for a robust defense, the ongoing work from today’s researchers is essential. One notable voice is Rahil Makadia, who recently completed a PhD in aerospace engineering at the University of Illinois at Urbana-Champaign and is exploring how we could alter an asteroid’s trajectory to avoid Earth.
In this episode of the Physics World Weekly podcast, Makadia explains his research on deflecting asteroids and discusses the real threats posed by near‑Earth objects—from minor inconveniences like shattered windows to the far more catastrophic possibility of global devastation.
Makadia emphasizes that the deflection plan must be executed correctly on the first attempt. His calculations indicate that a poorly planned deflection could allow an asteroid to return to Earth. In November, he published a paper (DOI: 10.1016/j.icarus.2025.116915) examining how a flawed deflection could steer an asteroid into a planetary “keyhole,” a narrow pathway that guarantees its return.
But there’s room for optimism. Makadia notes that our current knowledge of near‑Earth asteroids suggests no major collision is likely for at least the next century. Even if a threat appears on the horizon, we have ample time to develop and refine deflection strategies and technologies, ensuring we’re prepared well before any critical moment.
If you’re curious about how this evolving field balances risk and ingenuity, you’re not alone. The key question remains: how do we design a solution that doesn’t just work once, but works reliably every time? And what does that mean for the future of planetary defense—and for our responsibility to safeguard Earth? Would you like this explained with more practical examples of how a deflection would be implemented or with a closer look at the engineering challenges involved?
