lolz!
Yes earth collided but you do know that is a hypothesis and questioning it started about 2 yrs back:
The giant impact theory, which hypothesizes that the moon
was created by Earth’s collision with a Mars-sized planet (Theia), has long stood as one of the most popular theories as to how the moon was created.
This hypothetical collision is said to have produced a large disc of magma orbiting the earth that later became the moon as we know it
But in order for the hypothesis to remain consistent with the laws of physics, computer models suggest that 40% of the magma must have come from the Theia, and not Earth.
New research, published in
Nature Geoscience, tested titanium isotopes in 24 separate samples of lunar rock and soil and found that the moon’s proportion was effectively the same as Earth’s and different from elsewhere in the solar system.
The study explains that it’s unlikely Earth could have exchanged titanium gas with the magma disk because titanium has a very high boiling point.
The researchers aren’t refuting the “giant impact” hypothesis just yet, but they are calling into question. ...
Space2099 Forums - New Evidence Debunks Possible Origin Of Moon
Testing the Giant Impact Hypothesis
The initial temperatures of the Earth and Moon, the chemical compositions of their mantles, and the time when their cores formed in principle can be used to test the giant impact hypothesis. Unfortunately, planet formation and the subsequent formation of crusts, mantles, and cores is so complicated that much of the evidence may be destroyed. Furthermore, we do not yet have sufficient data to test all the possibilities.
One of the most important predictions of the giant impact hypothesis is that the Earth should be mostly molten when it formed. This would have led to complete separation of elements that concentrate into metallic iron when the core formed. The composition of the Earth's upper mantle today suggests incomplete core formation or addition after core formation of a veneer of rocky material containing metallic iron. The problem is that the extent to which elements concentrate in metallic iron varies with pressure, temperature, and the amount of available oxygen and sulfur, and not enough experiments have been done to map out all those variables. On top of all that, the experiments are extremely difficult to do.In addition, the continued growth of the Earth by large impacts might have led to episodes of magma oceans and core formation, not just one event. Each impact would not necessarily have led to a newly homogenized planet, either, as the impactors are thousands of kilometers across. It is not easy to thoroughly mix such huge masses of rock, even if molten. In fact, we do not know if Earth's lower mantle has the same composition as the upper mantle today.
Solar System Exploration: Science & Technology: Science Features: Origin of the Earth and Moon
Another article:
Huge Moon-Forming Collision Theory Gets New Spin
