SSIA.
Thanks,
Rob
Not necessarily and there are lots of variables which come into play. While planets do experience tidal forces from stars the effect is fairly small in the habitable zone and any moon would have much more impact.
It may be useful to point out that gravity does not hold objets in orbit but that it changes the entire geometry of spacetime. It may sound counterintuitive but orbiting bodies are traveling at a constant speed along the straightest possible path through spacetime.
The angular momentum of the system is conserved in this process, so if the the tidal forces do slow down the planets rotational energy would cause the orbital distance to increase.
The Earth would eventually be tidally locked to the moon given enough time but the transfer of earth rotational system to an increased orbit (thus speed) to the moons orbit is a slow process. The sun will engulf the Earth and the Moon before that tidal lock happens.
Given the right conditions the reverse is also true. Mars’ moon Phobos has a decaying orbit and it is increasing the rotational speed of mars as the distance of the Mars/Phobos system decreases as angular momentum of the system is conserved.
Red dwarfs have very long life spans, it wouldn’t be hard to imagine a planet being tidally locked. They are also common in the universe, odds are favorable to find at least one system this way. Although as rat avatar explains, there might not be enough time elapsed yet. Any star with planets would almost certainly have to made of supernova debris. It may take longer than 10 billion years to tidally lock a planet.
It would also depend on the rotation, stiffness and size of the planet.
As an example the planet had a tilted axis like Uranus (~98 Deg) it would never stop rotating because the axis is so tilted that the tidal forces would not transfer the angular momentum to other parts of the system.
A smaller planet would have less differential in gravitational acceleration and a solid one without liquid on the surface or an atmosphere would have less friction. Some back of the envelope math shows that Mercury in the Earths orbit, with the earths rotation may take trillions of years but I wouldn’t trust my math too much as I am not accounting for the increased orbit nor the core composition. So Moooooo…spherical cows!!!