A new study shows that the Taurid swarm contains fewer large asteroids than predicted, so the risk level from it is lower.
Astronomers have promising news about the potentially dangerous near-Earth asteroids: they are not as numerous as previously thought.
A University of Maryland-led research team using the ZTF telescope to scan large swathes of the sky has observed a stream of space debris known as the Taurid Swarm, drifting close to Earth. The Taurid Swarm, probably fragments of a large comet called Enka, is visible from Earth as impressive meteor showers every October and November. This region has long attracted astronomers because of the possibility that it hides dangerous asteroids, but until now scientists have not been able to verify or disprove the existence of such a danger.
"We took advantage of a rare opportunity that this asteroid swarm passed closer to Earth, and we could more effectively search for objects that could endanger Earth," said Ye Chuanchi, who oversaw the project. "Our findings show that the chance of being hit by a large asteroid in the Taurid swarm is much lower than we thought, and this is great news for planetary defense."
Prior to this study, researchers speculated that the Taurid swarm contained a significant number of large space rocks more than a kilometer in diameter that left a large object possibly up to 100 kilometers wide. Large objects can cause regional damage if they collide with the country, such as the Chelyabinsk asteroid that hit Russia and injured more than 1,600 people in 2013. Even larger objects can cause extinction-level events, like the asteroid that killed the dinosaurs 66 million years ago.
"Fortunately, we found that there are probably only a handful of asteroids in the swarm – maybe only nine to 14 – that fit this large size classification," Yeh explained. "Based on our findings, the diameter of the parent object that originally created the swarm was probably closer to ten kilometers and not a massive object 100 kilometers in diameter. We still have to be on guard against asteroid collisions, but these results are reassuring."
According to Yeh, the Taurid swarm holds important clues about the evolution of planets, especially because of its connection to Comet Anka. Anke, whose orbital period (the time it takes to complete one revolution around the Sun) is among the shortest of known comets, only 3.3 years, is also unusually large and dusty for a short-period comet (circling the Sun in 200 years or less). Considering all the available evidence, the scientists believe that Enka has undergone significant disintegration in the past - and may continue to disintegrate in a similar way in the future.
"Studying the Taurid Swarm helps us understand how small celestial bodies such as comets and asteroids form and break up over time," Yeh said. "Our research has implications not only for asteroid discovery and planetary defense, but also for our broader understanding of objects in the Solar System."
More of the topic in Hayadan:
