Mercury, Mars formed from leftovers of Earth, Venus

William Atkins
Friday, 06 February 2009 22:21

Science - Space

The rest of the band material (about 10%, based on Hansen) formed Mercury and Mars.

Because the majority of material formed the larger two planets, their orbits are much more circular than the smaller planets, which formed from much fewer materials.

The orbits of Mercury and Mars also became much more elliptical because they formed further from this thick band of material.

And, they now reside outside of Earth and Venus, with Mercury being the innermost planet from the Sun, and Mars being the outermost planet from the Sun, when comparing these four inner planets of our Solar System.

If Hansen is correct in his assumptions, and resulting computer simulation, then his conclusions can be tested for their validity.

If these four planets all came from the same materials, then they should have basically the same composition today, maybe only differing in specific percentages by their distance from the Sun.

That is, the percentage of one element may be found in less abundance on the outer two planets (Mercury and Mars) than the inner two ones (Earth and Venus)—or other such logical patterns.

For additional information on how astronomers think our Solar System first formed, please go to Solar System Formation, broght to you by the University Corporation for Atmospheric Research (UCAR).