On February 15th of 2013 at the midnight an asteroid named 2012DA14 discovered by NASA in 2012 passed through the earth geosynchronous ring. NASA released a simulation of the asteroid traveling path. As per the calculation, the mass and average diameter of this asteroid is 130×106 Kg and 45 meters respectively. A smooth particle hydrodynamics may used to model the trajectory to find the chance of hitting the earth. Simulations so performed mainly depend on observer data like polarization measurements, which is one of the oldest and accurate mechanisms. As the suns light fall on the asteroid, it is scattered away and so the plane of linear polarization is derived for the phase angle.
On this day itself after 16-hour gap an asteroid of size 20 m called as 2013, Chelyabinsk meteor slammed into the Russian atmosphere ended with blasts shattering into pieces. Well it seems to be that the scientists are unable to find out the hit of the asteroid before because of lesser diameter.