Were Mercury and Mars separated at birth?

New Scientist ^ | Monday, January 19, 2009 | unattributed

[SunkenCiv]

Line up Mercury, Venus, Earth and Mars according to their distance from the sun and you'll see their size distribution is close to symmetrical, with the two largest planets between the two smallest. That would be no coincidence -- if the pattern emerged from a debris ring around the sun.

Brad Hansen of the University of California, Los Angeles, built a numerical simulation to explore how a ring of rocky material in the early solar system could have evolved into the planets. He found that two larger planets typically form near the inner and outer edges of the ring, corresponding to Venus and Earth. A number of smaller bodies also form within the ring. These are typically scattered away by the larger two, but if they experience collisions on the way, they can end up in stable orbits similar to those of Mercury and Mars. Once beyond the ring, they cannot acquire mass and so remain pint-sized.

"This is nicely consistent with various properties of Mercury and Mars," says Hansen, who presented the work at the American Astronomical Society meeting in Long Beach, California. Both small planets have features that could have been caused by giant impacts. In one run of Hansen's simulation, Earth received a smash, too, much like the one thought to have created the Moon.

[SunkenCiv]

Note: this topic is from 01/19/2009. Adding, not pinging.

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[Rebelbase]

Obviously Mercury was the runt of the litter.

[SunkenCiv]

In the Solar System, among major bodies, Mercury’s density is just behind Earth’s.

[snip] Mercury is composed of metals and silicate material. Mercury’s mean density is the second-highest in the Solar System, which is estimated to be 5.427 g/cm3 – only slightly less than Earth’s density of 5.515 g/cm3.However, if the effects of gravitational compression – in which the effects of gravity reduce the size of an object and increases its density – then Mercury is in fact more dense than Earth, with an uncompressed density of 5.3 g/cm3¯ compared to Earth’s 4.4 g/cm3¯. [/snip]

http://www.universetoday.com/36935/density-of-the-planets/

[Rebelbase]

A tough little runt!

[SunkenCiv]

MARS AND EARTH MAY NOT HAVE BEEN EARLY NEIGHBORS
Astrobiology Magazine | 18 Dec, 2017 | Joelle Renstrom
Posted on 12/19/2017 7:27:49 PM PST by MtnClimber
http://www.freerepublic.com/focus/chat/3615189/posts

[SunkenCiv]

Note: this topic is from 01/19/2009. Just a little update.

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