How do you spot a dangerous comet that hasn’t been near Earth for more than 200 years?
By following its “footprints”—the meteor showers it leaves behind.
This innovative approach is the focus of research led by Samantha Hemmelgarn, a doctoral student at Northern Arizona University.
Her study, published in The Planetary Science Journal, uses data from meteor showers to locate long-period comets—those with orbits longer than 200 years.
These comets are difficult to detect until they’re dangerously close to Earth, which makes finding them early a key part of planetary defense.
Long-period comets are rare, but their potential impact could be catastrophic. Even a small one could cause massive damage, such as triggering an Ice Age or depleting Earth’s ozone layer.
To prepare for this unlikely yet devastating scenario, Hemmelgarn and her team developed a model that connects meteor showers to the parent comets that created them.
The researchers studied 17 known meteor showers from long-period comets.
By creating synthetic models of these comets’ paths, they predicted where the parent comets could be in space. When they compared their predictions to the last known locations of these comets, the model was surprisingly accurate.
This means scientists can now trace meteor showers back to the regions of space where the parent comets are likely hiding. With this knowledge, astronomers can use telescopes to locate these objects before they get too close to Earth.
“Even if the next extinction-level impact is millions of years away, it’s exciting to develop tools to trace shooting stars back to their origins,” Hemmelgarn said.
Hemmelgarn’s path to planetary defense wasn’t straightforward. She initially worked in retail management after earning a degree in marketing. But in 2019, inspired by her wife’s passion for her career as a genomic epidemiologist, Hemmelgarn decided to pursue her interest in astronomy.
In 2020, she began studying physics and astrophysics at NAU. Just a year after finishing her bachelor’s degree, she’s already contributing to groundbreaking research in planetary defense.
Hemmelgarn and her adviser, Nick Moskovitz, plan to expand their research to study 247 more meteor showers from long-period comets with unknown origins. They’ll use data from the upcoming Rubin Observatory’s Legacy Survey of Space and Time (LSST) to search for faint, hidden comets.
By connecting meteor showers to their cosmic origins, this work could help humanity prepare for and prevent future impacts from hidden space threats.
Source: KSR.
