Giant moon

[Chiberty]

What would the effect be if the moon was the same size as the earth (not if it suddenly changed, but if had been like that for at least long enough to get tidally locked)? What ramifications would the increased tidal force and the daily eclipses have on the weather, and how would the day/night cycles on the opposite sides of the planet differ?

[GoWibble he/him]

Same mass as our moon, or not? The cool part of eclipses would be non-existant . 

[Honorless he/him]

Life, as we know it, wouldn't exist

[GoWibble he/him]

3 hours ago, Honorless said:

Life, as we know it, wouldn't exist

and why (specifically) wouldn't it? if the planet was close enough to the sun, then it would be warm enough...

[Honorless he/him]

The origin of life on Earth was a very complicated affair, it required very improbable events to occur. Some kind of alien life may pop out with this scenario, we just don't know. Ignoring the astrophysical ramifications of having a satellite the same size as the planet (which would make them both planets), the main issue here would be the weather. Distribution of sunlight is an enormous factor governing temperature, currents, wind speed, atmospheric composition. Tidal forces are vital in governing oceanic currents which in turn forms the foundation of life here on Earth.

There should be many good articles and videos on the scenario which could explain the mechanisms better than me

Edited March 20, 2020 by Dreamer