> Over time, we could evolve a branch of humanity, "Homo ares"

These were called Belters (as in asteroid belt) in the excellent book series The Expanse, which is also an excellent sci-fi show available on Amazon.

The Expanse is quite good. But the earth/Mars/Belt differences are mostly cultural at least in the TV series. The "Belters" meme in SF has been around for a long time though. See Larry Niven for example. (And I'm sure it's older than that.)

Jeff Prucher's Brave new words gives its earliest attestation for the word as Niven's Warriors in 1966.

I would have guessed Heinlein but I don't see evidence he used that particular term although he had similar tropes in his books--e.g. Loonies in The Moon is a Harsh Mistress.

For similar tropes, see the meteor miners in E.E. Smith's Grey Lensman.

Oh, that looks like an interesting book! I read a lot of Niven back in college and I wondered if he invented the word "Belter", for Asteroid Belt dwellers.

In the books it's MUCH more than cultural, to the point that belters are unable to visit Earth without some difficulty due to too much gravity. Belters are described as much taller and more slender that people born and raised on Earth.

Beltalowdah physiological difficulty in adapting to gravity is a recurring plot point on the show. The culture difference exists in part because no Belter can survive long periods on Earth.

The novels portray each group has having more significant physiological differences. Naomi is supposed to be quite a bit taller than Holden, for example.

Makes sense. Easier to do in books than on the screen, especially a TV show. It's logistically just a lot easier to have everyone look like ordinary humans modulo superficial styling (and acting) differences.

Sorry to be pedantic, but no, those people were called "Martians". (His term, "homo ares", is referring to Ares, the god also known as Mars.)

The Belters lived in the Asteroid Belt, and were opposed to both the Terrans and the Martians. The Belters were the most different biologically because the gravity is so low, whereas the Martians got to enjoy the relatively high 1/3 g gravity of Mars.

Or evolve a branch of humanity that uses non-biological, radiation-hardened, easily-maintained, low-mass machines, instead of meat that doesn't grow correctly in low acceleration, uses chemical energy storage with no power generation capacity, and which gets scrambled without megagrams of shielding.

That is, develop general AI with a sense of responsibility and filial duty to its parent species, and which won't turn us all into paper clips.

This has been done in various hard science fiction novels. One series, the name escapes me at the moment, actually has one group of engineered human warriors that are quite different mentally from normal humans but they can survive in vacuum and have some insect-like traits physically. They can just drift through vacuum and quietly attach to the hull of an enemy ship.

Then you have the Old Man's War universe where the soldiers have engineered bodies and synthetic blood that they have control over (they can explode mosquito like creatures that try to feed on them as an example).

B. V. Larson's Star Force series sees characters changed by both nano bots and specifically-grown intelligent (as a colony) vats of bacteria.

Many science fiction series involve brain backus. If I'm not mistaken Peter F. Hamilton has them in his Commonwealth Saga and the Altered Carbon books and show have it. As does the previously mentioned Old Man's War series by Scalzi.

Daniel Suarez's book (his near-future hard science fiction books are quite good) Change Agent involves lots of serious genetic engineering, including changing one's entire appearance (rather dangerously) with a virus.

I think if we can manage to stay alive long enough as a species, we will be able to at least do everything except for the nano bots and possible even those if we get some significant physics and computational breakthroughs.

As a pre-teen in the mid 1990's a friend and I wanted to turn ourselves into anthropormphic creatures not unlike the creatures in the Island of Dr. Moreau (I believe it was actually the 1996 film adaptation that gave us the idea) and figured somehow a bacteriophage could be created to alter a host at a cellular level but we figured you'd need to find a way to selectively edit genes (that now exists with CRISPR and the like), suppress the immune system to prevent death from it overreacting during the process, and control the replication rate so the body wouldn't burn up with fever or have some sort of energy issue. If a couple of bored pre-teens could think that up while playing a MUD one afternoon, someone someday is going to start really tinkering with humans at a serious scale. It's already being done by biohackers.

> This has been done in various hard science fiction novels. One series, the name escapes me at the moment, actually has one group of engineered human warriors that are quite different mentally from normal humans but they can survive in vacuum and have some insect-like traits physically. They can just drift through vacuum and quietly attach to the hull of an enemy ship.

Pretty sure this was in some book in the Old Man's War series

Looks like you are right, 'homo astrum'. https://oldmanswar.fandom.com/wiki/Homo_Astrum

I read entirely too much hard science fiction to remember what comes from where, it's why as much as I'd love to I'll never write a space opera. I'd constantly be afraid I was unintentionally plagiarizing multiple authors.

Venus has 80% of Earth mass. Mars has 10% of Earth Mass. The simple math suggests, that these planets are destined to be combined in some distant future, but not by current civilization, so there is no real reasons to be concerned about anything at all.

Any of those projects of colonization in space is even greater waste of resources, compared to colonies in northern Canada, Antarctica, artificial islands or underwater cities.

I think you underestimate how radically different a world we'd live in if we had and inter solar system logistics network between colonies, earth and asteroids. It would be like another industrial revolution with untold and unimaginable changes. Likely with artificial islands, underwater cities, climate change reversal existing as mere side effects.

I've always wondered if Venus was as habitable as Mars on the surface which we'd choose. The lower gravity well of Mars makes it much easier to come back from which is practically a requirement to go there. But like you said, the jury is still out on how well we can live in lower gravity.

Getting back from Venus after just beginning to colonize it may not be possible with current technology.

I would choose Venus. The depth of the gravity well is less important when the colonists are being lowered into it from above rather than thrown out from the bottom. If you need something in orbit, you don't drop it down to the planet in the first place.

But as things are, the relative effort to terraform Venus, compared with Mars, is absolutely colossal. It essentially requires a full-blown robotic asteroid mining industry, wherein olivine asteroids are diverted directly to Venus, and magnesium and calcium are mined, sent to Jupiter to produce saturated hydrides, and those sent on to Venus. It will take 1000 years, minimum.

Mars can get realistic results within 200 years, just by diverting water-ice comets and managing temperature.

Getting back from Venus is as easy as launching from Earth: i.e., completely doable with present-day technology. The only issue is getting it there to begin with, but that's not really hard, though we'd probably need to launch several rockets here on Earth, and assemble stuff in space, to get all the mass needed for a single launch on Venus. Landing stuff on this hypothetical Venus would be much easier than on Mars, since this Venus has an atmosphere, and Mars only has an "atmosphere" (one that's 1/200 the pressure of Earth's, not really much of one), so we'd be able to use aerobraking, parachutes, etc. In fact, landing stuff on today's Venus is pretty easy, and the Soviets were doing this ages ago; the only problem is that landers didn't last long because of the heat and corrosive atmosphere.

Maybe we should work on terraforming it: use various processes to change the atmosphere and stop the runaway greenhouse affect, shed the excess heat into space, and build an earth-normal atmosphere.

However, it does seem like building rotating space stations (like O'Neil cylinders) is much more feasible.

Moon humans would be so weak I bet it would be easy to beat them up and steal all their moon cheese.