Preface: I'll be calling call the orbit described in the question title a "solar-oriented orbit" for the sake of convenience, as "a planet that has an axis of rotation that always pointed directly at the sun" is a bit of a mouthful.

Firstly, is a solar-oriented orbit even possible? I know the axes of most planets do not behave this way, in that their axes do not care where the sun is at any given point in time. Earth's orbit, for example:

earth's orbit Earth's orbit viewed at an angle, vs.
solar-oriented orbit diagram
Top-down view of hypothetical planet in a solar-oriented orbit. The arrows indicate the orientation of the axis.

I imagine that a system like this would function similarly to that of a tidally locked planet, as half the planet would receive constant exposure to the sun and the other half would never receive any.
Assuming that all other conditions of this planet are earth-like:

  • Orbits in the "Goldilocks Zone."
  • Has a molten core.
  • Contains water.

would life be able to develop on a planet that had one side continuously exposed to the sun? If life did come about, would it develop any differently than on a planet that was tidally locked? In other words, would the spins of a solar-oriented planet and a tidally locked planet be different enough to cause differences in life that would develop on them?

  • $\begingroup$ oh, thank you! Should I delete this question then? $\endgroup$ – BlockedWriter Apr 29 '19 at 3:06
  • $\begingroup$ This does not appear to be a duplicate to me. The linked question operates under the assumption that one of the planet's poles is pointed towards the sun, while this question does not orient either pole towards the local star. Instead, this question appears to ask about a planet with a rotational period equal to its orbital period. That might have the same answer, but it is not the same question. $\endgroup$ – MrSpudtastic May 9 '19 at 18:40

Hypothetically? Maybe. The northernmost and southernmost parts of the planet would be uninhabitable, though. A Supercontinent of land towards the sun and a Supercontinent of ice away from it. The only place where you might get survivable landscape is in and around the equator. Even then, the crops you would get would have to be very hardy and your animals and people would have a wonky circadian rhythm due to the lack of day/night cycle. It's possible something could form like this, but I think it'd be unlikely that such a world would exist sustainably enough that it'd develop complex life.

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  • $\begingroup$ There is no reason to think a circadian rhythm is a necessity for alien life (including animal life) to function. If a life form needs an approximate time keeping system of some sort, there are probably other biochemical routes to doing this. I also don't know why you think the "warm pole" would be uninhabitable - there's again no reason to think life can't evolve adapted to exist there. $\endgroup$ – StephenG Apr 29 '19 at 12:14
  • $\begingroup$ First off, you may want to look up what the circadian rhythm is in detail. You seem to misunderstand it, and it's not my place to give a crash course on endogenic biology in the comments section where it'd be against the rules to do so. Second, the "HOT pole" would be as inhabitable as the "cold pole". The land would be scorched earth. Third, I never said a circadian rhythm would be nonexistent, just wonky. $\endgroup$ – Sora Tamashii May 3 '19 at 3:58

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