chongo's Journal: 2002-SM asteroid update for 2002-Sep-30 00:30 UTC

We have a new entry at the top of the current impact risks called 2002-SM.

This object appears to be of significant size: ~1.32 km although its impact velocity (IF, and I do mean IF it were to hit the earth) is mid range: ~17.2 km/sec. If it were to hit the Earth, the effects would result in significant regional devastation.

The chance of impacting the Earth in the next 100 years is quite low: about 1 in ~2,000,000. The 1st close approach is not until 30 March 2015. The most significant approach given the current data (19 observations over 8 days) is 1 Apr 2020 (no fooling :-)) where it comes within ~22500 km of Earth +/- 200km. But even this event has less than a 1 in ~10,000,000 change of impacting Earth. The cumulative Palermo scale for 2002-SM is -2.11. But its Torino Scale value is 0.

It is very likely that over the next few days or weeks, additional observations will allow the model for 2002-SM to be refined. We see no long term trend in the model that would suggest that the risk from this object will become significant over the next few thousand years. It would not surprise us to see a refined model reducing the impact risk to the point where this object is removed from the potential Earth impactor table.

P.S. There is no change is status for 1997-XR2. That asteroid remains as the only non-zero Torino impact hazard scale object. The only reason why 2002-SM is listed higher than 1997-XR2 is because its Palermo scale is a about 0.33 higher. It is very likely that the next set of 2002-SM observations will drop it down the list, if not off of the list.