A research of the source regions of Apollo asteroids

Near Earth Asteroids (NEAs) is an important and popular subject in both research on the risk of a collision with Earth, and to explore their source mechanisms. Number of NEA population as of December 21st 2015 is 13677, and is increasing. In this thesis work, source regions of the Apollo asteroids which is the biggest population among NEAs has been studied, and dynamical routes has been tried to determined. For this, orbits were integrated for 10 Myr backward in time. To increase the statistics 6 clone orbits for the each asteroid orbit have been generated. In total, 38175 orbit integrations have been computed. Numerical integrations have been run on TÜBĠTAK ULAKBĠM-TRUBA clusters. Input orbits were prepared using each object's Tisserand parameters. Based on 10 Myr backward in time results show that source regions can be outer Solar System for objects have smaller Tisserand parameters and can be inner Solar System for objects have greater Tisserand parameters. At the end of the integrations 63.69% were terminated within normal integration time limit (10 Myr), 18.44% were terminated as their semi-major axis reached the 50 AU limit, 12.27% were terminated as hyperbolic orbits. Also, after 10 Myr of backward integration 71.79% of the orbits were still in NEA orbit region. In this thesis work, one other important result shows that there are two restricted regions caused by Jupiter and Venus. These regions are Q = 4.61 AU and Q = 0.728 AU lines which represents minimum aphelion for Jupiter crossers and Venus aphelion respectively. Q=4.61 AU region is also a lower limit for low eccentric orbits and upper limit for high eccentric orbits.