Update: Newly published paper in Nature Geoscience Atmospheric mountain wave generation on Venus and its influence on the solid planet’s rotation rate has open-access links in Science News, Motherboard, and Science.

There is a stationary gravity wave in Venus's very dense atmosphere. It is intermittent, but has been detected several times. See the NYTimes article Venus Smiled, With a Mysterious Wave Across Its Atmosphere for a discussion of recent observations by JAXA. See Akatsuki and Happy Birthday, Akatsuki!, celebrating it's first Venusian year at Venus.

Considering the extremely high density of the atmosphere near the surface, would it be possible for a suitably shaped spacecraft to "surf" or somehow remain aloft in this wave without propulsion, or even use it to rise high in the atmosphere, taking vertical data (e.g. composition, temperature, radar surface imagery and doppler profiling) and then gently return to the surface?

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above: "A sequence of images showing the stationary nature of the bow-shape wave above Venus when it was observed in December 2015. Planet-C" from NYTimes. credit: Planet-C/JAXA

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above: "An illustration of how gravity waves travel up mountains and into Venus’s atmosphere. Credit ESA" From How Mountains Obscured by Venus’s Clouds Reveal Themselves.

  • $\begingroup$ You could use a balloon if you could make it out of a material that could withstand the heat and the chemical reactions (e.g., I recall Venus having sulfuric acid in its atmosphere). $\endgroup$ – honeste_vivere Jan 30 '17 at 14:25
  • $\begingroup$ @honeste_vivere I'm asking about a craft using this articular atmospheric phenomenon to rise to high altitude without using propulsion. e.g. a glider. A balloon can generate lift on its own \on Venus anytime, anywhere, and so wouldn't be related to this question, would it? $\endgroup$ – uhoh Jan 30 '17 at 17:28
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    $\begingroup$ Ah yes, that is slightly different. In that case, they are still relying upon a pressure gradient but instead of "pushing air down" there is an unbalanced dynamic pressure due to the rising air. Okay, I think I am starting to see what your are thinking about... $\endgroup$ – honeste_vivere Jan 30 '17 at 18:48
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    $\begingroup$ O.k. , i'll think about it. Gliders could be very succesful within the polar vortices of Venus. en.wikipedia.org/wiki/Polar_vortex $\endgroup$ – Cornelisinspace Oct 13 '18 at 12:53
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    $\begingroup$ @Cornelisinspace If you think you've found a contradiction, why not ask about it in a new question? That will allow other users to look into it as well. This is a specific question and will have a clear answer, so I think you can ask it in a way that's both on-topic and not too broad. $\endgroup$ – uhoh Nov 20 '19 at 22:37

The density of carbon dioxide on Venus varies from about 70 kg/m3 at the surface to about 40 kg/m3 at a height of about 8 km, calculated at this website, so at a height of 5 km it could be about 50 kg/m3.

The wind speed near the surface of Venus varies from about 1 m/sec at the surface to about 25 m/sec at the height of about 8 km, being about 15 m/sec at a height of 5 km.

These are all very rough estimations relying on data given by Wikipedia.

The dynamic force at the surface on 1 square meter would be: 1/2 x 70 kg/m$^3$ x 1$^2$ m$^2$/sec$^2$ x 1 m$^2$ = 35 kgm/sec$^2$.

The dynamic force at a height of 5 km on 1 m$^2$ would be: 1/2 x 50 kg/m$^3$ x (15)$^2$ m$^2$/sec$^2$ x 1 m$^2$ = 2625 kgm/sec$^2$ !

Aphrodite Terra is the highland region near the equator that causes the wave in the atmosphere and looking at the image of its topography its height will be 5-7 km.
So we could assume that at a height of 5 km near the border of the highland the horizontal wind of about 15 km/sec would be forced to go vertical, so the vertical dynamic force there would be 2625 kgm/sec$^2$.

So with a surface gravity of Venus being 8.87 m/sec$^2$ and a horizontal surface area of 1 m$^2$ for the spacecraft it probably could have a mass of several hundred kg to stay above the highland region !

  • $\begingroup$ Thanks for the excellent analysis! I can't find a suitable humorous image to go along with "Surf's up!" right now nor 1950's movie clip in YouTube, but I'll keep an eye out for one. $\endgroup$ – uhoh Oct 12 '18 at 11:07
  • $\begingroup$ @uhoh It could be that my analysis is much to simple. $\endgroup$ – Cornelisinspace Oct 12 '18 at 11:36
  • $\begingroup$ It is simple because the angle of the wind above horizontal is not taken into account yet, but it seems there's plenty of room for reduction and still some kind of surfing air vehicle would at least stay aloft. I think a more in depth analysis is certainly possible but not necessary. $\endgroup$ – uhoh Oct 12 '18 at 13:57
  • $\begingroup$ @uhoh Is an in depth analysis possible if we don't have the necessary measurements ? $\endgroup$ – Cornelisinspace Oct 12 '18 at 14:13
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    $\begingroup$ @uhoh O.K, thank you for being informed about this interesting " wave ". $\endgroup$ – Cornelisinspace Oct 12 '18 at 17:49

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