Archive for February, 2013

What was it? (15 Februar 2013 Chelyabinsk Meteor Event)

February 18, 2013

The spectacular meteor event over the Chelyabinsk Oblast region (Russia) on 15 Februar 2013 gained worldwide attention among scientists and the broader public. Estimates for the mass of the meteoriod rank up to 10,000 t.  With estimated 17 m diameter this would correspond to a mean density of 3.8 g/cm3. However, a large trail cloud was observed – consisting of smoke (dust) and (likely?) water/ice. What about the water content of the trail? In a height of 30-50 km (stratosphere) the air is very dry. Thus, most if the water content in the trail stems from the fragmentating meteoroid. Estimating the size of the trail and assuming a liquid water content (LWC) of 0.01 g/m3 (which is about 1/3 of a cirrus cloud) on would get about 6000 t of water. This would be comparable to the meteoroid’s estimated mass (as an upper limit of course). If so, the object would have been more like a ‘dirty snowball’ – i.e. a comet! But I may be completely wrong…