Lecturer: Johan Kero (IRF) Date: 2015-03-05 10:00 Place: Aniara
The Chelyabinsk superbolide and IRF meteor observation activities
Johan Kero
Swedish Institute of Space Physics
Abstarct
The atmospheric impact on 15 February 2013 above Chelyabinsk, Russia, of a 17 to 20 metre-sized asteroidal boulder has increased the public interest of bright meteors. Events with a visual magnitude brighter than the albedo of the planets are usually called fireballs. Exceptionally bright ones are called bolides. The Chelyabinsk superbolide was brighter than the Sun. It transferred a large fraction of its kinetic energy to the atmosphere at 25-30 km altitude in form of an airburst. The airburst had an equivalent energy of about 500 kilotons of TNT or 30 times the A-bomb over Hiroshima. It generated low-frequency infrasound that was detectable even after having propagated twice around the globe. A major part of the impactor mass formed a dust plume, which later circumnavigated the northern hemisphere. The largest meteorite fragment recovered on the ground has a mass of 654 kg.
A nationwide Swedish Allsky Meteor Network to catch bright meteors, initiated at Uppsala University, is currently under development. The first video station in Uppsala is in operation since February 2014. IRF operate stations in Kiruna and Abisko since January 2015. The video network complements other meteor observation activities, as radar observations of mostly invisible meteors and infrasound observations of bolides.
Created 2015-01-20 10:04:00 by Mats Holmström Last changed 2015-03-03 11:38:34 by Mats Holmström
