Trojan-Planet-Figure-SETI-Institute-1200px (IMAGE) SETI Institute Caption The final orbits of the Trojan planet in a rotating reference frame where the primary star and the secondary planet are both fixed, at the left and right X, respectively. The plus sign marks the equilateral Lagrange point L4. Beginning after 600,100 orbits of the secondary around the primary, the Trojan is already in a banana-shaped orbit. At about 602,996 orbits, the Trojan escapes that oscillation and assumes an eccentric orbit closer to the primary star. Only about three orbits later, it has a close encounter with the secondary planet, and the simulation stops. Credit SETI Institute Usage Restrictions With credit License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.