I whole-heartedly agree with this statement and the leaps and bounds we as a human race would take working WITH each other instead of AGAINST each other would be amazingly huge. Alas, we cannot seem to manage to break ourselves from the ridiculous desire of always trying to be richer and more powerful than the next guy.

... but how exactly is it that 2 planetary bodies can collide, and "merge" into one larger planetary body? Wouldn't the collision obliterate both planets?