Geoefficiency of the Passage of the Chelyabinsk Meteoroid Through the Earth's Magnetosphere
Abstract
On 15 February 2013, a superbolide of about 17-metre diameter and about 17 thousand tons entered the Earth's atmosphere with a speed of around 18 km/s and at 03:20:33 UT exploded over Chelyabinsk at an altitude of 22 km. After the fall of the Tunguska Cosmic Body (TCB) on 30 June 1908, this is the second largest celestial body penetration into the Earth's atmosphere for the past 100 years. In the period prior to the explosion, the 17-thousand-ton block consisting of stones, metal and ice streaked through all the layers of the Earth's magnetic field - magnetosphere, plasmasphere and ionosphere. And if we assume that the passage of the celestial body through the Earth's magnetosphere was geoeffective, then the useful signal has to be traced after the meteoroid penetration into the Earth's magnetosphere 80-60 min before its explosion in the atmosphere. The analysis of AE AU, AL, AO and Kp indices has revealed that the bolide travelled through the Earth's magnetosphere during an extremely magnetoquiet period. The analysis of records from induction magnetometers of mid-latitude observatories Mondy (φ= 51.4°, λ= 100.5°) and Petropavlovsk-Kamchatsky (φ= 53.1°, λ= 158.4°) has shown the presence of a noise burst in geomagnetic variations over a frequency range 0.2-5 Hz in a time interval 02:45-02:58 UT, i.e. 35 min before the meteoroid explosion. The noise burst registered at the mid-latitude observatories against the quiet background of the geomagnetic field might have been caused by the interaction of the meteoroid with the Earth's plasmasphere. The analysis of the literature describing magnetic effects appearing during the passage and explosion of the Tunguska meteorite in the Earth's magnetosphere and atmosphere on 30 June 1908 has revealed that some researchers detected changes in the geomagnetic field variations 80 min before the explosion itself.
- Publication:
-
40th COSPAR Scientific Assembly
- Pub Date:
- 2014
- Bibcode:
- 2014cosp...40E2690R