Can a planet be tidally unlocked?
In my answer to another question, I suggested that the Super-Earth in question be tidally locked to its host star for a period of time while part of its surface experienced a bombardment. After that's finished, however, I'd want the planet to rotate normally, ideally with a rotation period similar to one Earth day. The problem is, I know of no examples of planets or moons becoming tidally locked and then tidal unlocked via natural means (although we've talked about doing this artificially).
Here are some specifications for my idealized version of the system:
- The star is a K-type main sequence dwarf of about $0.5L_{\odot}$ and $0.7M_{\odot}$.
- The planet is a Super-Earth of about two Earth masses, orbiting at $0.4$ AU.
- The planet's final rotation period should be $\sim$24 hours.
- Initially, there is an Earth-like atmosphere, and I would prefer for it to be retained, but that's not a necessity.
- There is no life on the planet yet, although there may be in the future.
I'd like to avoid catastrophic events like collisions with another planet, and I'd also want the planet's orbit to stay roughly where it is - in the habitable zone. Bearing this in mind, is it possible for this tidally-locked planet to naturally have its rotation period decreased to 24 hours within, say, 100 million years?
0 answers
0 comment threads