Tidally Locked Planets - How would time be measured?

[dryson]

We all know that Tidally Locked Planets or TLP's are planets that do not revolve or spin on their own axis and are locked in place by their sun so that only one side constantly faces the sun.

How would time be measured on such a planet?

We know that on Earth a day is approximately 24 hours from starting point A of where the Sun creates a shadow from the limb of a tree to the same point B where the shadow is created again which creates a day of measureable time. We also know that it takes Earth 365 days except on Leap Year to orbit the Sun which creates the Earthen Calendar.

Would time on a tidally locked planet be similar to being in a infinite time zone where there would not be any days but would be only years.

If the planet wobbled a little bit on it's axis would that constitute a unit of time? Would a person standing at the point where the planet created a unit of day actually be able to experience a time shift in so much coming from a perspective point of view that they could straddle the wobble point and be in the future and past at the same time while the planet wobbled back and forth over so slightly?

Would a tidally locked planet have to use the a coordinate system to keep track of the days travelled around the sun by using place marks on the sun that when the planet passed by the point on the sun that correlated with a location on the planet could that be constituted as being able to mark the passage of a day?

 

[MeteorWayne]

An interesting question as how to come up with a manageble shorter period like a day.

A year is easy, pretty much the way we do it, when the star pattern repeats on the dark or dusk/dawn areas where the temperatures would be constant, therefore more conducive to life.

 

[thnkrx]

Hmmm...

1) If the planet had a moon, that would help - especially if said moon had an orbital period of only a couple of earth days (larger more stable versions of Phobos / Diemos),

2) If the planets orbit had a bit of eccentricity to it, that might be enough to create 'seasons' of a sort.

 

[bdewoody]

Bigger question, could such a planet initiate life? Support it maybe if we went there but could lfe spring up there. And what about plants?

 

[MeteorWayne]

Since a tidally locked planet has very stable temperatures, ranging from very hot, to very cold, with all the moderate points in the thermal spectrum in between near the terminator, there are an infinate number of completely stable environments (i.e. niches) that organisms (if they formed) could permanently inhabit.

 

[eburacum45]

Tidally locked planets can't have moons, by the way; the process of tidal locking would cause any moon to spiral inwards and hit the planet or spiral out and be lost.

 

[dryson]

Bigger question, could such a planet initiate life? Support it maybe if we went there but could lfe spring up there. And what about plants?

Another good question. All forms of life even plant life has to go through down time in order to repair itself from the days event's, bugs trying to eat it, natural damage's such as UV radiation ect.

With a planet being tidally locked the natural events of the plant going through a nightly cool down period is not present.

The best way to understand how plants and animals would operate in such an environment is too study the plants and animals in the farthest most habitable artic zones on the planet.

I know Alaska area goes through six months of day light and six months of night. Alaska would be the perfect location in which to test how various plants and animals would react to being tidally locked.