"One of the challenges to the longstanding theory of the collision, is that a Mars-sized impacting body, whose composition likely would have differed substantially from that of Earth, likely would have left Earth and the moon with different chemical compositions, which they are not." —NASA Some theories have been stated that presume the Earth had no large moons early in the formation of the Solar System, 4.6 billion years ago, Earth being basically rock and lava.
"One of the challenges to the longstanding theory of the collision, is that a Mars-sized impacting body, whose composition likely would have differed substantially from that of Earth, likely would have left Earth and the moon with different chemical compositions, which they are not." —NASA بعض النظريات قالت أن الأرض في بداية تشكل المجموعة الشمسية قبل 4.6 مليار سنة لم تكن تمتلك قمرا يدور في مجال جاذبيتها، كانت الأرض عبارة عن حمم بركانية ملتهبة وكتل صخرية.