Collision With Earth's "Little Sister" Created the Moon

astroengine writes The primordial planet believed to have smashed into baby Earth, creating a cloud of debris that eventually formed into the moon, was chemically a near-match to Earth, a new study shows. The finding, reported in this week's Nature, helps resolve a long-standing puzzle about why Earth and the moon are nearly twins in terms of composition. Computer models show that most of the material that formed the moon would have come from the shattered impactor, a planetary body referred to as Theia, which should have a slightly different isotopic makeup than Earth.

Comments

Re:planet/planetoid

[RubberDogBone]

You can call planets planets or call them aardvarks. It makes no difference. The name we give it has no meaning except to the person giving the name. Another person might call it something else. Who can say which is right? You because you give it a name in English, or a first nation's person who named it in their language? Which is correct? And which is wrong?

But no matter.

The planet itself does not care what we call it. Our names mean nothing to it. The planet simply is what it is, as it was before humans gave it names and as it will be long after humans have faded from this universe.