On the possible geoefficiency of Chelyabinsk meteorite entering the Earth's magnetosphere

On 15 February 2013, a superbolid having a diameter of about 17 m and a mass of about 17,000 t entered the Earth's atmosphere at a velocity of about 18 km/s. At 03:20:33 UT, it exploded over Chelyabinsk, at a height of 22 km. After the fall of the Tunguska meteorite on 30 June 1908, it has been the second largest cosmic body entering the Earth's atmosphere in the past 100 years. A 17,000-tonne block of stones, metal and ice passed through all layers of the Earth's upper atmosphere (magnetosphere, plasmasphere and ionosphere). If we assume that passage of this cosmic body in the Earth's magnetosphere was geoefficient, then the desired signal had to be detected after the body entered the Earth's magnetosphere, 80-60 min before the explosion in the atmosphere. According to the analysis of АЕ-, AU-, AL-, AO- and K p-indices, the bolide passed the Earth's magnetosphere under very quiet magnetic conditions. Induction magnetometers at the ISTP SB RAS station for registering geomagnetic pulsations (the Republic of Buryatia, the Eastern Sayan, φ=51.4°, λ=100.5°) and at the IKIR FEB RAS Geomagnetic Observatory “Paratunka” (Kamchatka, φ=53.1°, λ=158.4°) showed a noise-like burst in variations of the magnetic field in the frequency range 0.2-5 Hz at 02:45-02:58 UT (i. e., 35 min before the meteoroid explosion). The anomaly registered at mid-latitude observatories under quiet geomagnetic conditions could be due to the interaction between the meteoroid and the Earth's plasmasphere. According to the review of papers dealing with occurrence of magnetic effects during the passage and explosion of the Tunguska meteorite in the Earth's magnetosphere and atmosphere on 30 June 1908, some researchers noticed anomalies in variations of the geomagnetic field 80 min prior to the explosion.