Why is Venus hell and Earth an Eden?
52 comments
·September 21, 2025azeemba
eru
Yes, first everything rusted, and then the excess oxygen collected in the atmosphere.
Many of our iron ore deposits we still mine today are from that rusting. (That iron used to be mostly dissolved in the oceans.)
duxup
Russian missions to Venus IMO are some of the coolest missions.
That's some brave stuff to try to pull off.
chasil
Venus does not have a molten core, and there is no magnetic field protecting the atmosphere from the solar winds.
This is not likely the sole reason, but it must be a factor.
Mercury does have a magnetic field, Mars does not.
kulahan
Mars, interestingly, was just determined to have a core almost identical to Earth’s as I understand it. This is not the sole determinant of course - you still need enough volatiles, enough gravity to maintain a hold on the lightest elements across billions of years, and tectonics to keep refreshing the atmosphere. Unfortunately for us all, Mars has none of those. There may be other significant factors as well.
codq
Without tectonics, is terraforming Mars even possible as a long term solution? This "Mars colonization" strategy seems like a pipe dream, no?
BlaDeKke
Was it ever anything else then a dream?
SJC_Hacker
Tectonics isn’t the issue
There would be little point in terraforming Mars. There’s plenty of places on Earth to terraform
riazrizvi
First order the explanation is simply, Venus is a hellhole because of atmospheric greenhouse effect exacerbated by proximity to the sun.
AnimalMuppet
Given Venus's atmospheric pressure, I'm not sure that "no magnetic field protecting the atmosphere" is a big part of the story. It's got plenty of atmosphere left.
echelon
> no magnetic field protecting the atmosphere
Venus has too much atmosphere. That's the problem.
wewewedxfgdf
Watch this magnificent documentary about the mystery of the surface of Venus.
Still a favorite after 30 years.
wewewedxfgdf
The Moon, gently stirring and moving the inner core like oatmeal.
sebmellen
Yummy. Mind the heat!
null
jrflowers
It’s because there’s no Arby’s on Venus. If we put an Arby’s up there it would start looking a lot better
derbOac
I guess we need to start colonizing other worlds then.
neuroelectron
Because of the distance from the sun
mitthrowaway2
Venus's albedo is so high that the insolation at the surface is even less than Earth's. Yet it's hotter than Mercury, which is closer to the sun than Venus.
The article says that volcanism is the reason, and that solar heating would not cause this result on its own, even though it's everyone's first guess.
axiolite
From TFA: "The sun alone cannot be responsible for making Venus the awful place it is today."
Mistletoe
That’s part of it but the dense CO2 atmosphere is the major issue. Don’t worry, we are trying to get there as fast as we can to Hell as well.
orionblastar
Don't forget the corrusive atmosphere that is acid and eats up space probes.
kulahan
Depends on elevation. It’s quite habitable with enough height.
gerdesj
Quite. Its just so.
bell-cot
I don't see any mention of the Theia Impact theory - https://en.wikipedia.org/wiki/Giant-impact_hypothesis - of the Earth/Moon system's formation.
Whether or not Theia was the cause - having a fast-spinning Earth and huge satellite in a low orbit* make Earth's situation profoundly different from that of Venus.
* https://en.wikipedia.org/wiki/Moon#System_evolution for starters
pfdietz
And once the water was in Venus' atmosphere, it could reach high altitude, where it would be dissociated by solar radiation. The hydrogen could then escape to space. The signature of this remains in the isotope ratio of deuterium to ordinary hydrogen in the atmosphere there: deuterium enriched by two orders of magnitude above the level seen on Earth.
taneq
Ok, so this is all leading to one very specific place: An anarchic society of steampunk airships harvesting Deuterium from the shirtsleeve zone in Venus’ upper atmosphere.
westmeal
What would they want with it?
est31
Deuterium might be the oil of the future as one can do fusion with it easily (in comparison).
pfdietz
To make enough giant H bombs to blow Venus' atmosphere into space?
This scheme would have some negative aspects.
BTW, hydrogen on Mars is enriched in D by a factor of 5 relative to Earth.
FridayoLeary
One odd theory i heard is that Earth is actually one giant superorganism. (When you look at how well all the ecosystems internact with each other it kind of makes sense). Like any organism, when invaded by a virus it heats up in a fever in order to kill it...
fifilura
Doing things in a chaotic way will increase entropy. Increased entropy is heat.
xnx
Even in the Goldilocks zone a planet still need so many specific things going for it to be the paradise Earth is. Anthropic principle strikes again!
The funny thing is that an oxygen-rich environment is a hell-hole! Oxygen is insanely reactive and will corrode anything. Even early life on earth found oxygen toxic. It was released as a waste product by early life and they were so successful that all that oxygen accumulated resulting in the Great Oxidation Event (https://en.wikipedia.org/wiki/Great_Oxidation_Event).
That likely resulted in many species going extinct!