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posted by CoolHand on Thursday February 09 2017, @09:37PM   Printer-friendly
from the built-fjord-tough dept.

No, not that kind of electronics:

Day or night, the mean temperature on Venus is about 460 °C, an extreme demonstration of the heat-trapping efficiency of the carbon dioxide that makes up most of the planet's thick atmosphere. At the crushing surface pressure of 9.4 MPa—93 times that on Earth—the gas exists in a supercritical liquid-like state. Overhead, sulfuric acid clouds tens of kilometers thick are blown around the planet in hurricane-force winds.

Of the 44 spacecraft sent to Venus since 1961, only a handful have attempted to land on its harsh surface. In 1982 the Soviet Venera 13 lander sent the image shown above before its instruments failed, despite the protection of a pressurized vessel filled with dry ice, after a mere two hours on the surface. The quick demise is unsurprising, as silicon electronics start to fail at temperatures above 250 °C when too many electrons are thermally excited across the bandgap. In the ensuing decades, silicon carbide materials technology has matured enough to make the heat-resistant semiconductor a more suitable choice for high-temperature applications. In an effort to prolong the life of SiC-based integrated circuits (ICs), a research group led by Philip Neudeck of NASA's Glenn Research Center has for the past several years toughened the metallic interconnects that link transistors; the protective, insulating layers around the interconnects; and other components. The effort has included choosing pure and relatively inert electronic materials that are stable at high temperature and whose thermal expansion coefficients are well matched.

Now Neudeck and colleagues have demonstrated that the robustly made ICs can operate successfully for several hundred hours in a simulated Venus atmosphere—no external cooling or sealed enclosure required.


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  • (Score: 3, Informative) by butthurt on Friday February 10 2017, @01:26AM

    by butthurt (6141) on Friday February 10 2017, @01:26AM (#465343) Journal

    The assertion being made is that the difference in surface temperature between Venus and Earth can be accounted for by differences in atmospheric pressure at the planets' surfaces, disregarding the fact that Venus' atmosphere consists mainly (96.5%) of carbon dioxide. The implication, I take it, is that carbon dioxide does not cause a greenhouse effect.

    The OP correctly tells us the format of the data on the NMSU site, as described in

    http://pds-atmospheres.nmsu.edu/PDS/data/mg_2401/data/mgn_rtpd.lbl [nmsu.edu]

    The data for the pressure closest to 1 bar is essentially as the OP says:

    S 3214 49.670 389.173 0.083 338.49 0.02 1.003948 0.000279 1.54995 0.00033 66.129 129.220 109.712 21.999 10354.237

    The average temperature of the Earth's surface can be estimated in various ways, but one estimate, from UCAR, is 15 degrees Celsius, which is close to 288 kelvins. That also agrees with what the OP wrote.

    I read this about the atmosphere of Venus:

    It is in fact know [sic] that the Venusian cloud deck is about 20 kilometres thick and it extends up to about 65 kilometres altitude over the planet. The first 'stellar occultation' measurements ever done at the Venus thanks to the SpicaV spectrometer, revealed that on the night side the cloud deck actually extends up to 90 kilometres altitude in the form of a fully opaque haze, and then continues as a more transparent haze up to 105 kilometres.

    -- https://web.archive.org/web/20070928123440/http://www.venustoday.com/news/viewsr.html?pid=21319 [archive.org]

    So according to that, clouds extend above the 50 km altitude to which the OP has directed our attention. An effect of those clouds will be to reflect some of the incoming sunlight before it reaches down to that altitude. The Earth, of course, also has clouds, but there are breaks in them. Venus has 100% coverage.

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  • (Score: 0) by Anonymous Coward on Friday February 10 2017, @06:34AM

    by Anonymous Coward on Friday February 10 2017, @06:34AM (#465414)

    The albebo adjusts...

    • (Score: 2) by butthurt on Friday February 10 2017, @07:52AM

      by butthurt (6141) on Friday February 10 2017, @07:52AM (#465423) Journal

      That's true on Earth: heat leads to evaporation, and moisture in the air can become clouds. Venus has very little water, but is cloudy because of sulphur dioxide. The clouds give it a high albedo (reflectivity).

      • (Score: 0) by Anonymous Coward on Friday February 10 2017, @08:07AM

        by Anonymous Coward on Friday February 10 2017, @08:07AM (#465428)

        Right, it seems that if it wasn't the sulfur dioxide clouds it would be something else to bring it into radiative equilibrium for a given pressure. Or that is a coincidence.