Meteor Explosion

Thankfully, the meteor explosion over Russia this morning did not kill anybody, which makes it easier to talk about this likely once-in-a-lifetime event.  The data are still preliminary, but the meteor explosion, estimated to be maybe 500 kT, released enough energy to register as about a magnitude 2.7 earthquake on seismographs. The explosion registered on the USGS earthquake site (look for the cursor in the image).  Interestingly, today's likely stony meteor was estimated to be about 17 m in size, which is a little larger than some estimates for the size of the more dense iron meteor that made the Odessa impact crater (see the previous post). See also: http://www.space.com/19829-russian-fireball-meteor-blast-infographic.html and http://www.space.com/19838-russian-meteor-blast-bigger-size.html. Meanwhile, a larger asteroid passed quietly quite near the Earth today, as predicted.  Lots of potential teachable moments with all this data, at least for unit conversions.