If we're talking same earth and cloud cover to the point where we still have daylight, but no clear night skies to star gaze - I think we'd still have pursued flight and at some point would rise above the clouds and inspire questions.

However our historical belief system would likely be more inclined to worshiping earthbased such as the water god and wind god - things we can't control rather than looking to the heavens. Might have been harder to make a specific calander as well.

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Spock Jenkins of the Vulcan Jenkins'.