This drawing illustrates how forming moons drew gas to themselves.
Image from: The New Solar System
The Co-Formation Theory
The co-formation theory explains the origin of the moon as an object which formed out of the primitive solar nebula
at the same time and roughly the same place as the Earth. As shown in this picture, while they were forming in the solar nebula, the nucleii of the moons-to-be (called protomoons) drew material
to themselves from the cloud of gas and dust around them.
Because the proto-moon was so close to the proto-earth the nebular material out of which they both formed ought to be very similar, composed mostly of rocky material rather than volatile gases.
The co-formation theory explains why the moon appears in the location it does but it does not explain the evidence that the Earth and Moon do not appear to be made of the same material.
Shop Windows to the Universe Science Store!
Learn about Earth and space science, and have fun while doing it! The games
section of our online store
includes a climate change card game
and the Traveling Nitrogen game
You might also be interested in:
The position of the planets in the solar nebula greatly affected their 1. size and 2. composition. This is because of the effect of how cold it was in the nebula. 1. The nebula was a lot warmer close to...more
The co-formation theory explains the origin of the moon as an object which formed out of the primitive solar nebula at the same time and roughly the same place as the Earth. As shown in this picture, while...more
People used to think that moons such as the Earth's moon or the moons of Jupiter had no atmosphere whatsoever. Now, however, measurements have shown that most of these moons are surrounded by a *very*...more
Unlike the Earth, which has a protective shield around it called the magnetosphere, the surface of the moon is not protected from the solar wind. This picture shows the magnetosphere surrounding the Earth,...more
Sometimes, in the fall, you may hear people call a Full Moon the "Harvest Moon". That's because farmers can stay in their fields late, after sunset, harvesting their crops by the bright light of a Full...more
Altocumulus clouds are part of the Middle Cloud group (2000-7000m up). They are grayish-white with one part of the cloud darker than the other. Altocumulus clouds usually form in groups and are about...more
Altostratus belong to the Middle Cloud group (2000-7000m up). An altostratus cloud usually covers the whole sky and has a gray or blue-gray appearance. The sun or moon may shine through an altostratus...more