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Small Asteroid On Collision Course With Earth
musatov writes "There's talk on The Minor Planet Mailing List about a small asteroid approaching Earth with a 99.8% probability of colliding. The entrance to the Earth's atmosphere will take place October 7 at 0246 UTC (2:35 after this story goes live) over northern Sudan, releasing the energy of about a kiloton of TNT. The asteroid is assumed to be 3-4 meters in size; it is expected to burn up completely in the atmosphere, causing no harm. As a powerful bolide, it may put on quite a show in the sky. For those advanced enough in astronomy to observe, check the MPEC 2008-T50 and MPEC 2008-T64 circulars. NASA's JPL Small Body Database has a 3D orbit view. The story has been already picked up by CNN and NASA."
This detail got left out of the story summary, making this sound like a bigger deal than it actually is. This is a routine, mundane event — only the prediction is newsworthy.
What this really means is that the new surveys are looking at more of the sky more frequently and deeper (seeing fainter objects), so now we are starting to catch things hitting the Earth that would have been missed in the past.
I wouldn't say this is a mundane event though, this is going to be bigger than the majority of fireballs that get seen. Yes, every few months, but most are over uninhabited areas and don't get seen. And they are not tracked in advance - so we'll get to see how big a fireball you get for a body whose size we have a rough idea of (a few meters across).
For technical updates, see
http://cfa-www.harvard.edu/mpec/RecentMPECs.html
5% of the meteors are iron. Iron is both denser and darker than the far more common stony meteor which means if the asteroid is made of iron, it'll be bigger than expected because the size estimates are based on the amount of light the asteroid is reflecting. If it's iron, its higher density, combined with its larger size, will improve the odds that some remnants will make earth fall.
If it makes earth fall it'll be by far, the most valuable meteorite ever since it's the first asteroid whose arrival was predicted. It'll literally be money from Heaven for whomever finds a piece.