Meteoroid trails can help detect comets years in advance

New research has found that meteoroid trails left by long-period comets could help scientists detect potentially dangerous comets years before they approach Earth. 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 in their wake.

Follow comet paths via meteoroid trails

The research has been accepted for publication in The Planetary Science Journal and is available as a preprint at arXiv. Long-period comets (LPCs) are known for their rare visits to the solar system. While comets like Halley’s Comet pass by Earth every 76 years, other comets appear only once every few centuries. Some of these distant comets could pose a significant threat if their orbits bring them close enough to Earth. A comet with a large enough impact could 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 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 planetary gravitational forces. This makes it easier to predict the orbits of the parent comets.

New method could save years of warning time

The study used existing data from 17 meteor showers with known comet parents. By simulating cometary streams and comparing them to known cometary paths, researchers were able to predict where to look for these long-period comets. The results suggest such methods could warn scientists years in advance before a comet poses a serious threat to Earth.

While this technique is not foolproof and has limitations, it is 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 well in advance, allowing for better preparation.

Challenges and future prospects

Despite its potential, the method cannot detect comets with orbital periods longer than 4,000 years because their meteoroid streams would be too sparse to detect. However, this new approach could significantly improve the early detection of more imminent threats, giving humanity a better chance to prepare for a possible comet impact.