New research suggests that meteoroid trails left behind by long-period comets could help scientists detect comets years before they approach Earth. These rare comets take hundreds or even thousands of years to complete their orbits and are often ignored until it’s too late to prepare for a possible collision. However, scientists have now found a way to track these comets by observing the streams of meteoroids they leave behind.
Tracking comet paths through meteoroid trajectories
This research has been accepted for publication in the Journal of Planetary Science, and a preprint is available through: arXiv. Long-period comets (LPCs) are known for their infrequent visits to the solar system. Comets like Halley’s Comet pass by Earth every 76 years, while others appear only every few centuries. Some of these distant comets could pose a significant threat if they orbited close enough to Earth. A comet that hits hard enough could release a huge amount of energy, perhaps equivalent to hundreds of thousands of megatons of TNT.
By studying the meteor showers caused by these comet fragments, researchers believe they can trace the paths of these dangerous comets. Samantha Hemmelgarn, a graduate student at Northern Arizona University and lead author of the study, explained that meteoroid streams from long-period comets are less affected by the planet’s gravity. This makes it easier to predict the orbit of the parent comet.
New method could provide years of warning time
The study used existing data from 17 meteor showers with known cometary parents. By simulating comet flows and comparing them to known comet paths, researchers are able to predict where to look for these long-period comets. The results suggest that this method could provide scientists with years of warning before a comet poses a serious threat to Earth.
While this technology is not foolproof and has limitations, it is an advancement for planetary defense. The upcoming Legacy Survey of Space and Time (LSST) using the Vera C. Rubin Observatory is expected to detect these long-period comets in advance, allowing for better preparation.
Challenges and future prospects
Despite the method’s potential, it cannot detect comets with orbital periods longer than 4,000 years because their meteoroid streams are too sparse to detect. However, this new approach could greatly improve early detection of more imminent threats, giving humans a better chance of preparing for possible comet impacts.
