Aftermath of Distant Planetary Collision?

gazurtoid writes "Astrobiology Magazine is reporting that astronomers have announced a mystery object orbiting the 8-million-year-old brown dwarf 2M1207 170 light-years from Earth might have formed from the collision and merger of two protoplanets. The object, known as 2M1207B, has puzzled astronomers since its discovery because it seems to fall outside the spectrum of physical possibility. Its combination of temperature, luminosity, and age do not match up with any theory. 'Hot, post-collision planets might be a whole new class of objects we will see with the Giant Magellan Telescope', said Eric Mamajek of the Harvard-Smithsonian Center for Astrophysics."

Re:Old Earth

[Anonymous Coward]

Earth after the collision that resulted in the Moon

That hypothesis has been challenged.

http://metaresearch.org/solar%20system/origins/original-solar-system.asp [metaresearch.org]

IMO, solar fission is a better theory than dust accretion, where "better" is defined as:

1. Provides genuine insight.
2. Does not contradict existing data.
3. Makes predictions that, if falsified, would disprove the hypothesis.

Short version: in order for a collision to produce a moon in a stable orbit, the impacting body must fall into a very narrow range of mass, velocity, and impact angles. This could have happened for one or two moons, but there are simply too many in the solar system to have all formed in this way. Furthermore, there is little evidence of all the failed attempts that must have also occurred. It is far more likely for candidate collisions to simply do damage, scatter some mass perhaps, or even shatter the unlucky planet.

Solar fission hypothesizes that planets are a necessary consequence of stellar evolution, and moons are a necessary consequence of planetary formation. As they age, heavier elements build up in their cores, causing a spinup - like a figure skater tucking their arms in. At first the parent body would swell at its equator, due to gravity being partially cancelled by centripetal force. Eventually the surface velocity exceeds escape velocity, and a chunk of matter is thrown. Stars and gas giants would throw chunks in pairs, one from each side, whereas rocky planets such as Earth and Venus would only create one moon at a time, since the planet would spin down before the second chunk can breach the crust.

Poke fun all you want. The physics are valid.

Cheers.