According to new study Jupiter’s powerful gravity can help supercharge a meteor shower caused by trailing chunks of the famed Halley’s comet.
Every October, skywatchers are treated to a dazzling show when the Orionid meteors, leftover bits of Halley’s comet, which zips by Earth every 76 years or so, burn up in our atmosphere. The Orionids are incredibly active from time to time, and this activity is generated by a complex orbital interplay among Jupiter, the comet and the meteoroids. Previous research had suggested that intense Orionid outbursts occur after the meteoroids fall into resonances (resonances are gravitational sweet spots in which objects’ orbits around the sun are related by a ratio of two whole numbers)with Jupiter’s orbit. The new study finds that Halley’s comet itself has likely been in resonances with Jupiter in the past, which in turn increases the odds of populating the Orionid stream with resonant meteoroids. The comet particles ejected during those times tend to clump together due to periodic effects from Jupiter. As said author Aswin Sekhar, of Armagh Observatory in Northern Ireland this resonant behaviour of meteoroids means that Halley’s debris is not uniformly distributed along its orbital path. When the Earth encounters one of these clumps, it experiences a much more spectacular meteor shower than usual. Sekhar determind that from 1404 B.C. to 690 B.C., the comet was likely trapped in a 1:6 resonance with Jupiter. Later, from 240 B.C. to 1700 A.D., the comet was in a 2:13 orbital resonance with Jupiter. According to study debris deposited during these two periods are directly linked to heightened activity in the Orionid meteor showers in some years.