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Comment by novalis78 | Hacker News Reader

It’s not a fantasy. Read “A case for Mars” if you are sincerely interested in the topic. Terraforming could dramatically thicken the atmosphere - a process that would take several hundred years. Yes, Mars would slowly lose it, but over 100s of millions of years. So you can keep the planet blue and green. Venus is harder but doable too. Can’t do that with the moon ever. So eventually, if we don’t WW3 ourselves, there will be 3 blue marbles in this solar system and an endless number of space and moon based habitats.

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It would be easier and cheaper to terraform/save our own planet than to do this. There is no point.

I think the proponents here are imagining a future a few hundred years from now where we have done that and there are 10s of billions of people in the solar system on multiple planets.

The point is trying to get past the Great Filter. Humanity faces threats from the cosmos beyond the ones we create on this planet.

We can do both: work to repair our planet while preparing for colonies on another.

The Great Filter is not likely an astroid or gamma ray burst type phenomena but rather the nature of intelligence that evolves in a competitive environment via evolution. Having two planets full of hyper competitive, violent social apes just means having two planets plagued by petty infighting. And if one planet is insane enough to nuke itself, what's to say it won't nuke the other?

If humans have a big enough presence on a second planet for there to be wars, we’ve almost certainly spread throughout the rest of the solar system and potentially have even put generation ships en route to other star systems, so even if earth and mars are nuking each other humanity will persist.

That scenario is somewhat unlikely anyway simply because access to resources is so much greater at that point, with there being thousands of times more of anything we have on earth in the asteroid belt and other parts of the solar system.

Isn’t it also very human to fight over control over those resources?

When supply is short enough to warrant it and control is a realistic possibility, sure. Even if humans mastered spacefaring tomorrow neither would be true for many centuries. The scales involved are utterly unfathomable.

Spoken like a true inyalowda. Maybe we skip the nukes and just send some rocks, sasa ke?

War is typically fought over limited resources. Getting to the proposed step would imply we have a handle on our inner solar system: https://hir.harvard.edu/economics-of-the-stars/

>War is typically fought over limited resource

Citation needed

The wars we've seen most recently have nothing to do with limited resources. Most wars through history have been about ego/ambition of royal assholes, and hatred/religious differences. Neither world war was about limited resources.

>"Most wars are not fought for reasons of security or material interests, but instead reflect a nation’s ‘spirit’"

https://blogs.lse.ac.uk/europpblog/2013/07/16/most-wars-are-...

While it is possible future wars might be fought over limited resources, that hasn't really been the main factor in most wars that we know of dating back at least 1000 years.

Interesting. Something like 'spirit' is tough to define. WWII could be categorized as a nation's spirit and revenge, but would Hitler had been able to whip up the nationalism required if Germany had been overflowing with resources and was prosperous?

Germany had plenty of resources to assault most of Europe. The resources they did have could have been used for good, but they chose to exterminate millions, and then tried to hide the evidence. They attacked every country around them because of twisted ambition and their corrupt fascist ideology. They were most certainly not correct in suggesting that it was the Jews and gays and everyone they didn't like that was the cause of any problems within Germany. They demonized "the other" to gain support for making war.

This planet has a clock that is running out.

If left to itself, even if humans never evolved on this planet, Earth dies in roughly 500m years. A complete total extinction event, as the carbon cycles break down and life on earth slowly starves.

More than 75% of the time life gets to enjoy on this planet is behind us.

500m years seems like a long time. It is not. 75% of life has passed us by, and we have only a single species so far that looks like it might be printing a golden ticket to get life off this rock. If this exercise fails, either another species rises to the calling (squids maybe? Idk), or everything goes extinct.

Human intervention on this planet is necessary. And getting life off this planet is necessary.

Advocating for anything else is advocating for letting all life on earth die.

*Citations very much needed to pretty much everything you just said.

Exact numbers vary… but I think it safe to say no matter what, it’s beyond our capabilities to understand. Either way, eventually the “sun goes boom” and we need to be long gone, or dead, as a species.

https://en.m.wikipedia.org/wiki/Timeline_of_the_far_future

A good entrance to the rabbit hole.

> 500m years seems like a long time. It is not.

I mean...talking about timelines like that is difficult because of the way we perceive time, I think most people can't have any reasonable discussion about something that far out. If we try to make it more comprehensible by saying humans have existed for 200k years and have 500m before Earth is uninhabitable, humanity is the equivalent of 12 days old in the scope of an 85 year life expectancy. We're newborns in diapers drinking milk, thinking about what kind of inheritance we'll leave for our great grandkids.

> We're newborns in diapers drinking milk, thinking about what kind of inheritance we'll leave for our great grandkids.

I know, aren't humans awesome?

Most species just eat all the corn and die, or convert the atmosphere oxygen causing a mass extinction.

Humans are looking up and going "oh wait, we are causing a problem, how do we solve this?" and then they follow it up with "and even if we solve it, we need to do something about the whole carbon cycle thing ending, how do we get life off this rock?"

I don't know of any other species that has gotten anywhere close to this.

Humans are great.

It’s not an either/or choice, we should do both, if only because learnings from performing planetary engineering on Mars will benefit similar efforts on Earth, but also because there’s no point in pigeonholing ourselves into a single planet. We’re cavepeople to Earth’s metaphorical cave and it would be wise to venture beyond it to become a true spacefaring civilization.

I wish I had more upvotes to give you.

We have the people and resources to to this, and the payoff is literally astronomical.

A big question would be how to divvy everything up.

Why is it always the same argument with you people? They’re not mutually exclusive. We must save our planet and we must terraform other planets.

Why backup your harddrive? - it's cheaper to just use the one you already have. There is no point.

My understanding is that the biggest challenge with terraforming Venus is the atmosphere. It's roughly 93 times the mass of Earth's, and mostly CO2. What do you do with it? Cycling it into the crust would take geologic spans of time. If you just cool it, you get deep oceans or thick glaciers of CO2 covering the planet. If you've got the energy budget to actually remove it from Venus completely (or sequester it rapidly), you've probably got the energy budget to do something easier like relocate a moon or dwarf planet.

Sure, 50-60km up in the atmosphere it's fairly hospitable, but colonizing that isn't terraforming.

You would split it to o2 and carbon. The real issue is the rotation speed of venus. Almost a year to rotate arround its axis.

What do you do with a 95% oxygen atmosphere with now only ~60 times the mass of Earth's atmopshere? You could make a small ocean out of it, but that's a huge amount of H to source.

We need to somehow get it to Mars.

That would be useful for about 1-2% of it; but it would be better to bring it to Mars as CO2 in the first place and crazy expensive. I like the idea, though. Maybe space habitats around Venus instead.

I've often wondered if it would be possible to spin Venus faster to shorten its day. Possibly by firing millions of large asteroids past Venus at just the right angle.

Added bonus is that you can mash all those asteroids together to give Venus an Earthlike moon.

Plus I wonder how such large scale gravitational engineering would affect the rest of the solar system.

About 323 million times the energy humanity produces in a year to spin up Venus [0] so probably not anytime soon.

[0]: https://nathanielmrouth.wordpress.com/2021/04/30/what-would-...

Thank you for a super interesting link!

It briefly mentioned the equatorial bulge that other, faster spinning, planets possess. Would it greatly damage the planet to spin it up?

I also didn't know that Venus' rotational energy is so low that we "could" actually spin it the correct way without spending much more energy.

You would be bombarded with radiation without a magnetosphere

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