Monday, May 21, 2012

2012 EO4 - who are you?


So where does 2012 EO4 belong in the Main Asteroid Belt? By cross-plotting the orbital elements of all asteroids in the belt one can find that they cluster in a number of families. The plots below show how 2012 EO4 compares with the rest of the population.

Apparently it belongs to Flora family based on its inclination and semi-major axis. However, the eccentricity is a bit too high (the orbit is elongated more than expected). Since it is thought that Flora family lost up to 50% of its mass through secondary collisions it is possible that 2012 EO4 is one of those "ejected" asteroids, which have very similar orbital elements with Flora, but greater eccentricities.

2012 EO4 is located close to the inner edge of the asteroid belt. It is possible that the Chicxlub impactor  was from Flora family! The composition of 2012EO4 should be similar to L-chondrite meteorites, which are thought to originate primarily from the inner asteroid belt. These meteorites are rich in olivine and orthopyroxene and have relatively low iron concentration, suggesting that the parent body was at least partially differentiated.