There’s been a few probes sent over, and the link lists a lot of “got a few pictures before being crushed by pressure” because the surface is so harsh. If we were to land another probe there, assuming we managed to land right next to where the old ones landed, would there be anything left? Or would the pressure and wind have scoured away any trace?

  • Mitchie151@lemmy.worldEnglish
    431·
    10 days ago

    On the surface of the planet, the atmosphere is extremely dense carbon dioxide, the sulfuric acid that makes landing such a threat is pretty much non-existent at the surface. The wind is also much slower at the surface, the probes measures only 2-4kmh. The probes that landed typically fail due the the temperatures overwhelming the electronics. Most electronics we manufacture are only good up to around 100 Celsius, with specially designed stuff good to around 150c.

    I’m no expert, but as the atmosphere is mostly inert at the surface and the wind speed is relatively slow I would attribute damage to the probes over time to temperature and pressure rather than corrosion/erosion. That said, it’s been a long time and even trace amounts of sulfuric acid at surface level could lead to corrosion over time but to what extent I’m not sure.

    The temperature is well below the melting points of the metals I would assume they were made from such as titanium and steel. Aluminium however would be too weak under the pressure and temperature conditions and would be crushed, though it probably wouldn’t melt.

    Barring any major volcanic eruptions nearby, under normal conditions I’d hazard a guess that the probes on the surface are still there, perhaps largely in tact.

    • ch00f@lemmy.worldEnglish
      9·
      9 days ago

      Do you have a source for this?

      2-4km/h is slow, but there’s a lot of energy there when the atmosphere is 92x denser than Earth at the surface.

      Also plenty of H2SO4, but looks like it sits mostly above the CO2 in the atmosphere.

      • Successful_Try543@feddit.orgEnglish
        10·
        9 days ago

        I don’t want to be nitpicking, but, while at ground level, the atmospheric pressure is 92 bar (Earth: ~ 1 bar), the Venus atmosphere at ground level is ‘only’ 50 times denser than on Earth, 65 kg/m^3 vs. 1.2 kg/m^3.

        Yet, 2-4 km/h wind velocity in the over supercritical atmosphere on planet Venus are not directly comparable with some wind here on earth.

        • ch00f@lemmy.worldEnglish
          7·
          9 days ago

          Never thought about this before, so trying to logic it out. If Venus’s atmosphere is primarily CO2 which is denser than air, how does 92x pressure not work out to >92x density?

          • Successful_Try543@feddit.orgEnglish
            8·
            9 days ago

            Looking at the ideal gas law, p·v = R·T (v is the specific volume, the inverse of the mass density), I’d say beside the pressure p, i.e. the weight of the atmosphere above a point, it’s at least the temperature T that is quite different between Earth and Venus. An other factor is the compressibility of the fluid; our air is quite compressible, the atmospheric pressure is quite low and the ideal gas law thus gives a good approximation.

            As an atmosphere consisting of multi-atomic fluids, on Venus mainly CO_2, in an over supercritical state is far beyond what can be considered to be an ideal gas (low pressure, single-atomic gas), there are several other factors to be taken into account. The van der Waals law or the Clausius law are usually models to choose when dealing with real gases. However, as mentioned, the atmosphere is in an over supercritical state, i.e. beyond the critical temperature and pressure, the fluids are not in gaseous state, thus an even more complex material model is needed, to describe its behaviour.

            But to give an idea of the effect: When you measure the pressure and the density of the water of an ocean in different depth, you’ll notice the pressure increases linearly with depth, while the mass density of the water remains almost constant. Its low compressibility is why water often is treated as an ‘incompressible’ fluid. Similarly, this may work in an over supercritical fluid, as it has some properties that are similar to gases and some, e.g. lower compressibility, that are more similar to liquids.