An update based on Russian sources about the size and quality of the meteorite, how much damage was done, how many people were injured.
I found help through a link on page 12:_http://oko-planet.su/phenomen/phenomenday/166032-v-chelyabinske-progremel-vzryv.html I give both Russian source and an approximate translation so others can verify.
First something about what they think may be in the lake, (if it has not been or will be stolen.) :)
They quote it from _gazeta.ru and the title is "Ученые: основная масса метеорита, упавшего в Челябинской области, остается в озере Чебаркуль"]По мнению ученого, размер метеорита, находящегося в озере, может достигать 50—60 см в диаметре.
«То, что мы привезли, — это малюсенькие обломочки, всего около 50—53 осколков, все — миллиметрового размера. Это то, что удалось собрать на снегу около воронки», — сказал он.
(T: i skip the title that is for reference only.) According to the scientist, the size of the meteorite that is in the lake may reach 50-60 cm in diameter.
[…..] “50-53 fragments, all millimetre sized pieces. That is what we succeeded in finding in the snow near the crater", he said. (T: I guess he talks about the crater in the ice on the lake.)
Secondly there are new numbers of the number of injured people and damaged houses:
_http://www.interfax.ru/russia/txt.asp?id=291046 said:
Метеорит упал в озеро
Москва. 18 февраля. INTERFAX.RU -
[..]
Сейчас специалисты Уральского федерального университета собираются исследовать найденные обломки более детально. Основные выводы уже сделаны: метеорит относится к классу обыкновенных хондритов. Это каменный фрагмент с содержанием железа около 10%.
[...]
По данным МЧС на начало субботы взрывная волна повредила 2962 здания, из них 34 учреждения здравоохранения, 11 учреждений социальной защиты, 361 школьное и дошкольное образовательное учреждение.
В результате взрывов пострадали 1491 человек, в том числе 311 детей. Основная часть раненых получила порезы осколками разбитых стекол. Состояние 21 пострадавшего утром в понедельник оценивалось как средней тяжести.
I translate just the parts in bold:
Title is Meteorite fell in the lake. The meteorite belongs to the class of common chondrites. It is a stone fragment with about 10 % iron.
According to the Ministry of Civil Defence, Emergencies etc. Saturday morning the number of damaged building were 2962, of these 34 health institutions, 11 social institutions, 361 schools and kinder gardens.
As a result of the explosion 1491 suffered, including 311 children. The main part of the injuries was due to broken window glass. Monday morning the situation of 21 injured was characterised as moderately serious.
Thirdly, I elaborate on the material of the meteorite
Wiki has about this type of chondrites:
_ https://en.wikipedia.org/wiki/Chondrite said:
Ordinary chondrites
Ordinary chondrites are by far the most common type of meteorite to fall on Earth: about 80% of all meteorites and over 90% of chondrites are ordinary chondrites.
L chondrites have Low total iron contents (including 7-11% Fe-Ni metal by mass). ~46% of ordinary chondrite falls belong to this group, which makes them the most common type of meteorite to fall on Earth.
A useful glossary index about meteoritics, the science of meteorites, is found on: __https://en.wikipedia.org/wiki/Glossary_of_meteoritics
Fourthly, I try to calculate the mass of the object using the above data and the information about the size from NASA.
According to this site _http://meteorites.wustl.edu/id/density.htm the density density of the L-chondrite is between 2.5 and 3.96 g/cm^3 with an average of 3.35 based on measurements of 160 meteorites.
Suppose the meteorite was a perfect ball, and the diameter was 17 meters, this would give a radius of 8.75. The volume would be (4/3)*pi*(7.5)^3=2806m^3 which multiplied by 3.35tons/m^3=9400 tons
In other words the object was if it was solid and round like a ball around 9400 tons, but since it has holes, is not round and the exact density is unknown it is not exact and most likely quite a bit less, provided the 17 meters are on the mark.
And last the Russian are not sure NASA is right and argue that NASA has exaggerated. The link is here: _http://ria.ru/science/20130219/923732790.html#13613133953213&message=resize&relto=register&action=addClass&value=registration
Some how, they are not able to give any exact numbers. They say the energy was between, 10 and 500 kilotons but more likely 100-200 kilotons, and that the size was between 5 and 20 meters.
How might that add up? The average between 5 and 20 is 12,5 meters. If one compare 6.25^3 with 8.5^3 one gets the numbers 244 and 670. And 244/670=36% is more or less one third of the NASA estimate.
NASA should have equipment to determine the exact size and mass, or so I think. The Russians may have and certainly have a lot of experience with nuclear bombs and know what damage was caused. Who is right is hard to tell. But, what is certain is that a lot of people were injured. First reports were hundreds, then 950, 1200 and now 1491 people.
Edit=fixed quote box and parenthesis.
