The metallic snows of Venus

Artist's conception of metallic "snow" on the flanks of Maat Mons on Venus (based on a Magellan radar image). Credit: NASA / JPL
Artist’s conception of metallic “snow” on the flanks of Maat Mons on Venus (based on a Magellan radar image). Credit: NASA / JPL

When one thinks about snow-capped mountains, the last place that might come to mind is Venus, a place where on the surface it is hot enough to melt lead. But as it turns out, Venus does have snow – sort of.

Venus has mountain ranges just like Earth does; the tallest mountain in fact, Maxwell Montes, is 11 kilometres (6.8 miles) in height – 3 kilometres (1.8 miles) taller than Mount Everest! Venus’ mountains are also capped with “snow” – except that in this case, the snow is made of heavy metallic minerals, such as lead sulfide and bismuth sulfide. As seen by radar on two orbiting probes, Pioneer Venus and Magellan, the Venusian highlands are more reflective than the lowlands. This was a mystery until more detailed measurements indicated that it was the result of chemical deposition. The snow particles are light grey in colour, with a shiny lustre.

The Venusian snow is actually more like frost in a sense. The temperatures are so high, up to 480 ˚C (840 ˚F), that the metallic minerals become like a vapour or mist, which then condenses at higher altitudes, just like water frost or snow on Earth.

The amount of sunlight hitting Venus’s surface is less than on Earth, due to the perpetual heavy cloud cover. Even so, the reflective surface of the snow-capped mountain peaks would be quite a sight to see.

In comparison, there was also the recent report that high up in Venus’ atmosphere, it can get cold enough, -175 ˚C (-285 ˚F), for carbon dioxide snow! Interesting how a planet that is so blistering hot on its surface can have not one, but two kinds of snow. Just not snow as-we-know-it.

So perhaps the mountains of Venus are not the best place for skiing, unless you can, ironically, take the heat, but they are still a place of stark alien beauty.

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0 thoughts on “The metallic snows of Venus

  1. Does if follow then that there are mineral “glaciers” and even possible rivers of melt “water”? Fantastic!

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