Speculated ‘doomsday’ asteroid swarm less likely to impact Earth, study finds

Astronomers have found that the potential “doomsday” asteroid swarm is less dangerous than previously thought.

The Taurid swarm is a group of space rocks that drift close to our planet.

Researchers from the University of Maryland used the Zwicky Transient Facility (ZTF) telescope to study the Taurid swarm.

Previous estimates suggested there might be a significant number of large, potentially hazardous asteroids in this swarm. But the new study has revealed a much lower risk. The study revealed a lower number of dangerous space rocks in our cosmic neighborhood.

“We took advantage of a rare opportunity when this swarm of asteroids passed closer to Earth, allowing us to more efficiently search for objects that could pose a threat to our planet,” said Quanzhi Ye, the project lead from the UMD’s Department of Astronomy.

Ye added: “Our findings suggest that the risk of being hit by a large asteroid in the Taurid swarm is much lower than we believed, which is great news for planetary defense.”

ZTF telescope observations

Taurid swarm is believed to be the remnants of a large comet called Encke. Interestingly, Encke exhibits an exceptionally short orbital period of 3.3 years and possesses an unusually large size and dust content for a short-period comet.

The Taurids are known for creating meteor showers in October and November when they enter Earth’s atmosphere.

Before this study, scientists assumed that the Taurid swarm might contain many large asteroids, possibly up to 1 kilometer in size. These asteroids could cause significant damage if they hit Earth, similar to Russia’s Chelyabinsk asteroid incident that injured 1,600 people in 2013. Even larger asteroids could lead to mass extinctions, like the one that wiped out the dinosaurs.

The ZTF telescope was used to study this stream of space debris.

“Fortunately, we found that it’s likely there may only be a handful of asteroids—perhaps only nine to 14 of them—that fit this large size class in the swarm,” Ye explained.

The author added: “Judging from our findings, the parent object that originally created the swarm was probably closer to 10 kilometers in diameter rather than a massive 100-kilometer object. While we still need to be vigilant about asteroid impacts, we can probably sleep better knowing these results.”

Continous monitoring required

Scientists hypothesize that Encke has broken apart into smaller pieces in the past and may continue to do so in the future.

Utilizing advanced facilities such as the ZTF telescope, the researchers intend to conduct follow-up observations of the Taurid asteroid swarm during its future close approaches to Earth. As per the press release, the next opportunities are expected to come in 2025 and 2026.

Further exploration of the Taurid swarm could provide clues about how comets evolve and break apart. The Taurid swarm may also shed light on planetary evolution.

“Studying the Taurid swarm helps us understand how small celestial bodies like comets and asteroids form and break apart over time,” Ye said. “Our research has implications not just for asteroid detection and planetary defense, but also for our broader understanding of solar system objects.”

The researchers highlight to continue to be cautious and develop better ways to find asteroids.

The findings were presented at the annual meeting of the American Astronomical Society’s Division for Planetary Sciences on October 7, 2024.