David Kipping

It gives rise to tides, especially early on when the moon was closer, those tides would have covered entire continents.

And those rock pools that would have been scattered across the entire plateau may have been the origin of life on our planet.

the Moon forming impact may have stripped a significant fraction of lithosphere off the Earth, which without plate tectonics may not have been possible.

We'd have had a stagnant lid because there was just too much lithosphere stuck on the top of the planet.

There are speculative reasons but intriguing reasons as to why a large Moon may be

not just important, but central to the question of having the conditions necessary for life.

So moons can be habitable in their own right, but they can also play a significant influence on the habitability of the planets they orbit.

And further, they will surely interfere with our attempts to detect life remotely from afar.

The thing that's interesting about binary objects is that they're very common in the universe.

Binary stars are everywhere.

In fact, the majority of stars seem to live in binary systems.

When we look at the outer edges of the solar system, we see binary Kuiper belt objects all the time, asteroids basically bound to one another.

Pluto-Sharon is kind of an example of that.

It's a 10% mass ratio system.

It almost is, by many definitions, a binary planet, but now it's a dwarf planet.

So I don't know what you call that now.

But we know that the universe likes to make things in pairs.

It's not a complete freak of the universe to be alone, but it's more common for Sun-like stars.

If you count up all the Sun-like stars in the universe, about half of the Sun-like star systems are in binary or trinary systems, and either half are single.

But because those binaries are two or three stars, then cumulatively, maybe like a third of all Sun-like stars are single.