Meteorite trails left by long-period comets can help scientists detect potentially dangerous comets years before they approach Earth, new research has revealed. These rare comets, which take hundreds or even thousands of years to complete their orbits, often go unnoticed until it is too late to prepare for a possible collision. However, scientists have now found a way to track these comets by observing the meteoroid streams they leave behind.
Tracking comet paths through meteorites
The study has been accepted for publication in The Planetary Science Journal, and is available as a preprint arXivLong-period comets (LPCs) are known for their short trips across the Solar System. While comets such as Halley’s Comet pass by Earth every 76 years, other comets appear only once every few centuries. Some of these distant comets may pose a significant threat if their orbits bring them close enough to Earth. A large enough impact comet can release enormous amounts of energy, potentially equivalent to hundreds of thousands of megatons of TNT.
By studying meteor showers caused by the debris of these comets, researchers believe they can track the paths of these dangerous comets. Samantha Hemelgarn, a graduate student at Northern Arizona University and lead author of the study, said meteor streams coming from long-period comets are less affected by the planets’ gravitational forces. This makes it easier to predict the orbits of the original comets.
New method could provide years of warning time
The study used existing data from 17 meteor showers with known comet parents. By simulating comet streams and comparing them with known comet paths, researchers were able to predict where to look for these long-period comets. The results suggest such methods could give scientists years of advanced warning before a comet poses a serious threat to Earth.
Although this technology is not infallible and has limitations, it is still a step forward in 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 earlier, allowing better preparation.
Challenges and future prospects
Despite its potential, this method cannot detect comets with orbital periods longer than 4,000 years, because their meteoroid streams would be too low to detect. However, this new approach could significantly improve the early detection of more imminent threats, giving humanity a better chance of being prepared for a potential comet impact.
