We are alone in the Universe, unless we guess otherwise.

[JimC]

It could be that there are many planets out there covered in a slime of something similar to single-celled photosynthetic prokaryotes, but none that have made the rare and improbable jumps to eukaryotic cells, then multi-cellular life, then intelligence...

Go, go slime worlds!

[NineBerry]

Earth was slime world for most of its time

[JimC]

Then we made a series of improbable evolutionary leaps which culminated in Donald Trump!

[NineBerry]

He might be the missing link to slime

[rainbow]

I recall reading about ideas on intertidal zones being a likely environment for the very first life to form. Of course there are other candidates, including oceanic hydrothermal vents.

We don't know that an impact is the only way for a binary planet system to form, nor do we have an accurate idea of how common or uncommon such binary planets are.

The cyclic strengthening and weakening of ocean tides over tens of millions of years is likely linked to another, longer cycle: the formation of Earth's supercontinents every 400 to 600 million years, according a new study. The new findings have implications for the formation of our planet, its climate and the evolution of life on Earth, according to the study's authors. The new research suggests long-term changes in tidal energy, which control the strength of the ocean's waves, are part of a super-tidal cycle dictated by the movement of tectonic plates.

https://www.sciencedaily.com/releases/2 ... 131614.htm

[pErvinalia]

Tides enabled surfers. Surfers are (somewhat) intelligent life.

[laklak]

Some are marginally intelligent, but then there are Surf Nazis. They must DIE.

[Hermit]

Some are marginally intelligent, but then there are Surf Nazis. They must DIE.

Most of them are not even marginally intelligent. Just like motor boat owners.

[laklak]

Huh. Stupid ones have sailboats. With manual pump toilets.

[rainbow]

Huh. Stupid ones have sailboats. With manual pump toilets.

Duh. Rich ones have yachts. With Manuel pump toilets.

Que?

[rainbow]

I would say that it's rather unlikely that Earth is the only planet of its size in the Universe with a large moon, orbiting in what we consider the habitable zone. Given that there are probably billions of planets in our own galaxy, I expect that many planets exist in the Milky Way that are similar to Earth in these details.

It would probably be a bit beyond me to calculate the probability of a planet being hit by another object, so that they don't break into little bits, but collide at just the right angle and velocity to form a binary planet system like the Earth - Moon.

I'm sure if we fed all the parameters into a giant computer and waited for a while, it would tell us the answer.

Abstract

Recently the single-impact hypothesis for forming the Moon has gained some favorable attention. We present in this paper a series of three-dimensional numerical simulations of an impact between the protoearth and an object about 0.1 of its mass. For computational convenience both objects were assumed to be composed of granite. We studied the effects on the outcome of the collision of varying the impact parameter, the initial internal energy, and the relative velocity. The results show that if the impact parameter is large enough so that the center of the impactor approximately grazes the limb of the protoearth, the impactor is not completely destroyed; part of it forms a clump in a large elliptical orbit about the Earth. This clump does not collide with the Earth, since the effects, first, of vapor pressure gradients during the impact, and later, of angular momentum transfer due to the rotation of the deformed Earth, have modified the ballistic trajectory. However, since the orbit of the clump comes close to the Earth (within the Roche limit) the clump will be destroyed and spread out to form a disk around the Earth. The amount of angular momentum in the Earth-Moon system thus obtained tends to fall short of the observed amount; this deficiency would be eliminated if the mass of the impactor were somewhat greater than the one assumed here. The scenario for making the Moon from a single-impact event is supported by these simulations.

https://www.sciencedirect.com/science/a ... 3586900886

[rainbow]

...meanwhile in Russia:

MOSCOW, May 28. /TASS/. Russian scientists confirmed through computer modelling that the Moon could have originated concurrently with the Earth rather than as a result of our planet’s collision with a celestial body, Roscosmos Executive Director for Long-Term Programs and Science Alexander Bloshenko told TASS.

https://tass.com/science/1161459

[Clinton Huxley]

There's nothing but humanity and the Void, and my money is on the Void.

[rainbow]

It could be that there are many planets out there covered in a slime of something similar to single-celled photosynthetic prokaryotes, but none that have made the rare and improbable jumps to eukaryotic cells, then multi-cellular life, then intelligence...

Go, go slime worlds!

Why would the Creator of the Universe have slime worlds?
How would they praise him?

You really didn't think this one through, did you?

[Clinton Huxley]

You don't see slime moulds fucking each other over for a God damn percentage