TomTerrific
Well-Known Member
http://www.slate.com/blogs/bad_astronomy/2013/02/18/asteroids_and_meteors_why_are_we_suddenly_seeing_so_many.html
This article pretty well summarizes what we know about the Chelyabinsk meteor and goes into more detail why it would not have been seen in the BR area.
The question of what was reported seen in BR is a good one. It could have been an Iridium satellite, the space station, or an aircraft. I'll call it a UFO until we have a good reason to call it something else.
This article seems to have the diameter and weight down better. I calculated the density using data previously given and came up with numbers less than 1.0g/cm3. 17m and 10,000ton works out to 3.5. Meteor density is given as 2-8g/cm3, depending on the Fe content.