[This is a very important fact that scientists have known about for a long time. This is a very bizarre twist in understanding life on Earth AND finding life on other planets. The moon is a really weird object with a really weird effect. This is a fact that crops up again and again. It is a very well established fact. A planet, by itself, is too unstable for life to exist. The Moon, which is a very weird object, allows this. It's something I've known about for a long time. See the short quote from the article below. Lots of scientists have pointed this out. Jan]

Here it is:-

Moons may be essential to life

In a press release, study co-author Siegfried Eggl of the University of Illinois at Urbana-Champaign explained further applications of the method in determining the habitability of exoplanets:

“If we can use this method to show there are other moons out there, then there are probably other systems similar to ours. The moon is also likely critical for the evolution of life on our planet, because without the moon the axis tilt of the Earth wouldn’t be as stable, the results of which would be detrimental to climate stability. Other peer-reviewed studies have shown the relationship between moons and the possibility of complex life.”

Maybe the discovery of exomoons is the first step to finding life elsewhere in the cosmos. Understanding the similarities and dissimilarities with our solar system is a great place to start.

Source: https://bigthink.com/surprising-science/exomoon-life/