How Gaseous, Neptune-Like Planets Can Become Habitable

An anonymous reader writes: Life as we know it requires small, rocky planets. The gas giants of our solar system aren't habitable (to our knowledge), but a research team has discovered that smaller, Neptune-like planets can be transformed into gas-free, potentially habitable worlds with a little help from red dwarf stars. Such planets are usually formed far out in a planetary system, but tidal forces can cause them to migrate inward. When they reach the habitable zone of their host star, they absorb far larger amounts of x-ray and ultraviolet radiation. This can eventually boil off most of the the gas atmosphere, leaving behind the core: a small, rocky world capable of supporting life.

Comments

An X-Ray baked hellscape sound perfect

[jandrese]

This sounds like a great way to make a Mercury type planet, but I'm not so sure it will be so great at making a place you would want to live.

next daft question

[ihtoit]

Did Earth once possess a much larger (Neptune-sized or even larger?) atmosphere, maybe sometime way before the Hadean period? I can see the hydrogen/helium literally boiling off by a warming sun, leaving behind the heavier gases. Maybe we're looking at what Earth has now completely in the wrong way, considering that even at 430km the ISS is being slowed by atmospheric drag - common assumption has it that "Space" occurs at what, shy of 100km? This Karman line isn't a solid boundary with Space above and Air below, it's a convenient mark on a piece of paper.