\n<\/p>\n
The University of Maryland published this original article on October 7, 2024. Edits by EarthSky.<\/p>\n
Exciting news! Six months ago, just as we were ending our spring fundraiser, EarthSky received a $50,000 gift, with a request that it be used to collect matching funds. Whoa! We were so thrilled and grateful. And now it\u2019s time to make good on our obligation. Please help us meet this match by donating to EarthSky today!<\/p>\n
Astronomers have good news about potentially hazardous asteroids lurking near our planet: there aren\u2019t as many as we thought.<\/p>\n
A team of researchers led by the University of Maryland used the Zwicky Transient Facility (ZTF) telescope to survey large expanses of sky. They investigated a stream of space debris known to drift near Earth called the Taurid swarm. The Taurids are likely remnants of a large comet called Encke. They appear from Earth as highly visible meteor showers in October and November. This region has long intrigued astronomers due to its potential for harboring hidden, dangerous asteroids. But researchers could not confirm or disprove the existence of such hazards \u2026 until now. <\/p>\n
The group announced its findings at the American Astronomical Society\u2019s Division for Planetary Sciences annual meeting on October 8, 2024. <\/p>\n
Quanzhi Ye, who supervised the project and is an assistant research scientist in UMD\u2019s Department of Astronomy, said: <\/p>\n
\nWe 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. 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.<\/p>\n<\/blockquote>\n
Large asteroids in the Taurid swarm?<\/h3>\n
Prior to this study, researchers speculated the Taurid swarm contained a considerable number of large, kilometer-class space rocks. These rocks would\u2019ve been left behind by a large object possibly up to 100 kilometers (62 miles) wide. Large objects can cause regional damage if they were to impact Earth. For example, the Chelyabinsk asteroid that hit Russia in 2013 injured more than 1,600 people. Even larger objects can cause extinction-level events, such as the asteroid that killed the dinosaurs over 66 million years ago.<\/p>\n
Ye explained: <\/p>\n
\nFortunately, we found that it\u2019s likely there may only be a handful of asteroids \u2013 perhaps only nine to 14 of them \u2013 that fit this large size class in the swarm. 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.<\/p>\n<\/blockquote>\n
Important clues to planetary evolution<\/h3>\n
According to Ye, the Taurid swarm holds important clues about planetary evolution, especially due to its connection to Comet Encke. Encke has the one of the shortest orbital periods (the time it takes to complete one rotation around the sun) of known comets at just 3.3 years. It\u2019s also unusually large and dusty for a short-period comet (orbiting the sun in 200 years or less). Considering all available evidence, scientists believe Encke experienced significant fragmentation in the past. And it may continue to fall apart similarly in the future. <\/p>\n
Ye said: <\/p>\n
\nStudying the Taurid swarm helps us understand how small celestial bodies like comets and asteroids form and break apart over time. Our research has implications not just for asteroid detection and planetary defense, but also for our broader understanding of solar system objects.<\/p>\n<\/blockquote>\n
While the study\u2019s results are reassuring, the team believes that they also underscore the need for ongoing vigilance and improved detection capabilities. Using advanced facilities such as the ZTF telescope, which can efficiently conduct vast sky surveys and track potentially hazardous near-Earth objects, the researchers plan to conduct follow-up observations in the coming years when the Taurid asteroid swarm passes close to Earth again. Ye said:<\/p>\n
\nWe have opportunities in 2025 and 2026 to further refine our results. As a result, we\u2019re excited to continue this important work.<\/p>\n<\/blockquote>\n
Bottom line: Astronomers studying the debris that causes the Taurid meteor shower said it\u2019s unlikely there\u2019s a doomsday asteroid swarm with many large asteroids hidden in the debris.<\/p>\n
Via University of Maryland<\/p>\n
<\/div>\n
\n