
Venus’ Ocean of Air and Clouds - crazydoggers
http://www.planetary.org/blogs/guest-blogs/2019/venus-ocean-of-air-and-clouds.html
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basilgohar
I cannot help but think that this provides some vindication for one of Isaac
Asimov's more embarrassing[0] book titles...

[0]
[https://en.wikipedia.org/wiki/Lucky_Starr_and_the_Oceans_of_...](https://en.wikipedia.org/wiki/Lucky_Starr_and_the_Oceans_of_Venus)

~~~
TMWNN
Nothing embarrassing about it. Until the early 1960s, scientists (and, thus,
science fiction) were split about 40/40/20 on whether Venus was mostly ocean,
mostly swamp, or mostly desert.

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ur-whale
This article really makes me wonder why mars is such a focus of space
exploration right now, when Venus seems to be a much more interesting target:

    
    
        - closer (or so I believe, and according to [1])
        - more atmosphere to do stuff with
        - more natural resources to collect
        - more energy to collect
    

Granted the conditions are rough down there (pressure, temperature), but are
they really rougher than those found on Mars. Different, granted, but harder?

Also, depending where you place yourself in the atmosphere, conditions might
actually not be that bad.

Is landing a long lasting robot on Venus really harder than doing it on Mars?

[1] [https://sciencing.com/mars-venus-closer-
earth-4940.html](https://sciencing.com/mars-venus-closer-earth-4940.html)

~~~
JumpCrisscross
> _closer (or so I believe, and according to [1])_

Venus is physically closer, but that isn't the best measure of "closeness" for
propulsive space travel. The right metric is delta-v, "a measure of the
impulse per unit of spacecraft mass that is needed to perform a maneuver" [1].

Ignoring aerobraking, it takes almost 5x the energy to get to Venus compared
to Mars [2]. (Side note, to drive the point home: it's easier to boost objects
out of the Solar System, from Earth, than to send them into the Sun.)

[1]
[https://en.m.wikipedia.org/wiki/Delta-v](https://en.m.wikipedia.org/wiki/Delta-v)

[2]
[https://www.dailymail.co.uk/sciencetech/article-2679107/Mind...](https://www.dailymail.co.uk/sciencetech/article-2679107/Mind-
interplanetary-gap-Space-subway-map-reveals-travel-planets-moons-solar-
Tube.html)

~~~
travisporter
Actually, I found that it is not as drastic as 5x on this site.
[https://space.stackexchange.com/questions/2156/does-a-
missio...](https://space.stackexchange.com/questions/2156/does-a-mission-to-
venus-orbit-require-less-propellant-than-a-similar-mission-to)

~~~
JumpCrisscross
> _it is not as drastic as 5x on this site_

Those are deltas-v from low-Earth orbit to low-Venus and low-Mars orbits,
respectively.

Going from low-Venus orbit to the Venusian surface costs as much as getting
from Earth to low-Venus orbit _plus_ getting from Earth to Mars almost 3x over
[1].

[1]
[https://www.dailymail.co.uk/sciencetech/article-2679107/Mind...](https://www.dailymail.co.uk/sciencetech/article-2679107/Mind-
interplanetary-gap-Space-subway-map-reveals-travel-planets-moons-solar-
Tube.html)

~~~
Mirioron
Wait, what? The article mentions that the delta-v on the chart is required to
go from the surface of Venus to a low Venusian orbit, not the other way
around.

I don't see why it would cost the same to go down from orbit to the surface.
In fact, I'm pretty sure that a probe in a low Venusian orbit would decay on
its own just like they do in low Earth orbit. I really don't see how going
from a low Venusian orbit to the surface would be costly.

~~~
JumpCrisscross
> _The article mentions that the delta-v on the chart is required to go from
> the surface of Venus to a low Venusian orbit, not the other way around_

Delta-v is symmetrical. Putting something in orbit is mostly about
accelerating tangentially to the surface, not about going up. Taking something
out of orbit is mostly about accelerating tangentially to the surface, not
about falling down.

> _I 'm pretty sure that a probe in a low Venusian orbit would decay on its
> own just like they do in low Earth orbit_

Orbital decay for small objects is slow aerobraking. It is slow, requires a
heat shield, and is structurally stressful.

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raxxorrax
I think Venus is one of the uglier planetary bodies but this was a fascinating
read and the images are spectacular, especially that of Venus' nose on the
pole.

Would be interesting to get behind as to why the atmosphere is spinning that
crazy and why the planet spins clockwise like Uranus.

~~~
throwaway_law
>Would be interesting to get behind as to why the atmosphere is spinning that
crazy

Not an answer, but Venus doesn't have an internally generated magnetic field,
so charged particles/solar winds interact with Venus' atmosphere. These
interactions between the Solar Winds and atmosphere themselves create a
magnetic field which appears different in size/shape than planets like us with
internally generated magnetic fields. Again not an answer by any means, just
interesting food for thought.

