A Big Day for Science Geeks

There are two interesting developments to discuss, so let's get right to them:


1. Today, several chunks of a decommissioned satellite will strike the surface of the Earth (hundreds of kilograms at hundreds of km/h)

For the past week, earthlings have been warned that a defunct satellite will enter the Earth's atmosphere on Friday, Sept 23, 2011.  Unlike small satellites, this one, the size of a bus, will not entirely burn up upon re-entry.  Although the simulation is hard to predict with high precision, it is certain that a significant portion of the satellite will survive the re-entry, and will find a terminal velocity in the region of 300 km/hr.  Like the weather, aerodynamic problems involving extreme heat transfer are difficult to solve with much accuracy long in advance.  The location of where on Earth these satellite chunks will land is still somewhat up in the air.

NASA explained last week that this should not worry us, as there is a 75% chance that the said pieces will hit water (gee, thanks for the geography lesson).  As of this morning, we now know that the satellite pieces will strike the Earth in its Southern Hemisphere.

This sort of thing happens roughly once per year...