
Venus' Spectral Signatures and the Potential for Life in the Clouds - rbanffy
https://www.liebertpub.com/doi/full/10.1089/ast.2017.1783
======
cyrus_
The upper atmosphere of Venus is an extremely under-appreciated location in
the solar system!

\- Closer than Mars

\- 90% of Earth gravity (compared to 30% for Mars)

\- Atmospheric shielding mass equivalent to Earth's (protected from solar
radiation, unlike Mars)

\- Large amounts of carbon dioxide and sulfuric acid, with some other trace
gasses. You can make fuel, extract water and grow plants from that.

\- At 50km altitude, you have ~1atm of pressure, and breathable air is a
lifting gas, so you can put a balloon full of air up there and it will float
and support a good amount of extra weight. If it punctures then it will just
slowly leak, not explosively decompress.

\- Temperature ranges from 27-75C, so thermal issues are pretty easy.

\- Ample solar influx for power.

Source:
[https://en.wikipedia.org/wiki/Colonization_of_Venus](https://en.wikipedia.org/wiki/Colonization_of_Venus)

Obviously you're floating in the air, so you'd have to bring in metals and
minerals externally, e.g. from earth or via asteroid mining, or maybe in the
future we could build machinery capable of mining the surface despite its
brutal conditions. Or, you know, forests in balloons that you gather timber
from.

So yeah, "build a cloud city on Venus" is definitely a crazy idea, but not
nearly as infeasible as "terraform Mars" I think! Furthermore, as this paper
demonstrates, there are some incredibly interesting and unresolved scientific
questions that justify going (as if the sheer beauty of "cloud cities on
Venus" is not reason enough!)

~~~
ValleyOfTheMtns
I agree that Venus is under-appreciated as a colonisation target, but I
haven't seen anyone attempt to address the issue of how you "land" in the
atmosphere without touching down on the surface? And if you ever want to get
back to Earth, how do you launch a rocket within the atmosphere? These are
non-trivial engineering problems that need to be addressed.

First things first, lets get a probe floating around in the clouds of Venus.

~~~
avz
> I haven't seen anyone attempt to address the issue of how you "land" in the
> atmosphere without touching down on the surface?

Spacecraft in the Venera program successfully deployed balloons following
atmospheric entry, see [1]. The balloons stayed up in the atmosphere for more
than 46 hours.

> how do you launch a rocket within the atmosphere?

Atmospheric launch into a suborbital trajectory was demonstrated by White
Knight, see [2]. There exist air-to-space missiles, see [3]. Admittedly, none
of these are fully fledged space launches from the atmosphere, but they show
it's not entirely outside the real of the plausible.

[1]
[https://en.wikipedia.org/wiki/Vega_program#Balloon](https://en.wikipedia.org/wiki/Vega_program#Balloon)
[2]
[https://en.wikipedia.org/wiki/Scaled_Composites_White_Knight](https://en.wikipedia.org/wiki/Scaled_Composites_White_Knight)
[3]
[https://en.wikipedia.org/wiki/ASM-135_ASAT](https://en.wikipedia.org/wiki/ASM-135_ASAT)

~~~
skykooler
The Pegasus launcher launches satellites to orbit from an air-launched
vehicle.

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sper4uxue
I'm not a chemist or anything, but the best theory I've read so far of the
origin of life is the metabolism-first theory of Michael J. Russell [1] et al.
This theory models life as a natural heat-engine occurring in any far-from-
equilibrium system in the universe where dissipation of energy is frustrated.
Life would have started in hydrothermal vents, initially as inorganic
chemistry driven by a proton-gradient, later organic, then free-living.

On the face of it, life must have started on Mars and Venus around the same
time as on Earth (~4 billion years ago). The puzzle then is why is there no
obvious life on our sibling planets now. One could make habitable-zone type
arguments or a need for certain combinations of chemicals, or other special-
conditions like plate-tectonics[2]. But one could equally argue that once life
is running to any extent, it changes its environment and creates homeostasis
(Gaia).

[1]
[https://science.jpl.nasa.gov/people/Russell/](https://science.jpl.nasa.gov/people/Russell/)

[https://www.youtube.com/watch?v=SF2uj0Oxqhg](https://www.youtube.com/watch?v=SF2uj0Oxqhg)

[http://dx.doi.org/10.1098/rstb.2012.0254](http://dx.doi.org/10.1098/rstb.2012.0254)

[2][https://www.quora.com/Is-plate-tectonics-on-earth-caused-
by-...](https://www.quora.com/Is-plate-tectonics-on-earth-caused-by-the-
presence-of-life)

~~~
jacobush
As I read the article, Venus might already be in homeostasis, albeit a much
less complex one than our earthly.

Bacteria creating sulphuric acid, keeping the environment they survive in.

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TheOtherHobbes
Colonisation seems like wishful thinking. It doesn't matter that the pressure
outside is 1 atm when you have an incredibly corrosive atmosphere which will
chew through all realistic candidate materials in weeks, a need for perfect
atmospheric seals to keep out the smell of the H2S in the atmosphere, and
roaring convection currents that are going to give any balloon occupants a
wild ride.

It's absolutely not going to be like floating peacefully in a balloon gondola
on earth. More like an endless high-G theme park ride.

~~~
cyrus_
I've tried to get my head around the limited information out there on how much
turbulence there is at various altitudes but I don't know enough about that
area of physics to get a good sense of it. Do you have a citation for the
"roaring convection currents" claim? Fast winds aren't necessarily a problem,
its the derivatives that cause problems...

