What is the Largest Asteroid Ever to Hit Earth?
The largest asteroid ever to hit Earth was probably Theia, a Mars-sized body that formed over 4 billion years ago, during the early days of the solar system. Theia formed in a Lagrange point, a gravitationally stable region in the Earth’s orbit, located on the opposite side of the Sun. Eventually, orbital fluctuations caused this body to oscillate closer and closer to the Earth, and eventually, they collided, throwing up a greater volume of molten rock than all the present-day continents combined. Some of this molten rock was ejected so forcefully that it entered orbit, aggregated, cooled, and became our Moon. This scenario is called Giant Impact Theory, and it accurately explains most features of the Earth-Moon system, such as why the chemical composition of the Moon is similar to that of the Earth’s crust. Since Theia, the largest asteroids known to impact the Earth were much smaller, maxing out at around 10 km (6 miles) in size. Larger asteroids may have hit the Earth during the per