A recent fireball captured over the UK on October 4th, 2014. Credit: the UK Meteor Observation Network.
On October 31st 2005, trick-or-treaters across the central U.S. eastern seaboard were treated to a brilliant fireball, a celestial spectacle that frequently graces October skies.
Mid- to late October is fireball season, a time when several key meteor showers experience a broad peak. We’re already seeing an uptick in fireball activity as monitored by numerous all-sky cameras this month, including NASA’s systempositioned across the United States. Three lesser known but fascinating showers are the chief culprits.
The main meteor shower on tap for the month of October is the Orionids. This shower radiates from the Club of the constellation Orion, and is the product of that most famous comet of them all, 1P Halley. Halley’s Comet is actually the source of two annual meteor showers, the October Orionids and the May Eta Aquarids. We’re seeing the inward stream of Halley debris in October, and Orionid velocities average a swift 66 kilometres a second. The radiant rides highest for northern hemisphere observers at 4 AM local, and 2014 sees an estimated zenithal hourly rate (ZHR) of 20 predicted to arrive on the mornings of October 21st through the 22nd.
The Orionids experience a broad peak spanning October 21st through November 7th, and 2014 sees the peak arrive just two days prior to the Moon reaching New phase. The Orionids have exhibited an uptick in activity as high as 50-75 per hour from 2005-2007, and it’s been suggested that a 12 year peak cycle may govern the Orionids, as the path of meteoroid debris stream is modified by the gravitational influence of the giant planet Jupiter. ...more