Giant 'Great Valley' Found on Mercury | Hacker News Reader

Giant 'Great Valley' Found on Mercury

thescienceexplorer.com

72 pointslucodibidil12 comments

> "This is a huge valley. There is no evidence of any geological formation on Earth that matches this scale," said Laurent Montesi.... The valley is about 250 miles wide and 600 miles long, with steep sides that dip as much as 2 miles below the surrounding terrain. To put this in perspective: if Mercury's "great valley" existed on Earth, it would be almost twice as deep as the Grand Canyon and reach from Washington, D.C. to New York City, and as far west as Detroit.

Although they were formed by a different process, this does sounds kind of like Earth's oceans. Do they not qualify as a geological formation?

Near where I grew up there is a place called The Pannonian Plain. It's a remnant of a dried up sea.

So maybe we just don't call those geological formations valleys? https://en.m.wikipedia.org/wiki/Pannonian_Basin

I believe Earth's oceans are generally thought of as the baseline, with the continents being relatively higher "plateaus" above them (rather than the continents being the baseline with ocean floors being "valleys" in between).

Either way, the Mariana Trench seems to dwarf the valley that's described in the article.

Take that silicon valley ;)

In all seriousness, this is very interesting and sounds kinda similar to glaciers.

Reading this type of stuff makes me feel very small and insignificant - kind of like the total perspective vortex. It makes me truly sad to think that I will be long gone by the time humans are exploring these things.

What's the temperature down there?

Probably very similar to the temperatures anywhere else on Mercury's surface - with no atmosphere, temperature doesn't vary much with altitude. So, somewhere around 500-700K during the (3-4-month-long) daytime, and around 100K at night.

"Because the crater is deep, and the Sun never gets very high off the horizon at the pole, there are parts of the crater floor that are permanently in shadow; they literally are never illuminated by the Sun. Those spots can be very cold; well below the freezing point of water" from this article http://www.slate.com/blogs/bad_astronomy/2012/11/29/_mercury...

That's only for polar craters, which this is not. The poles are in any case quite cold by Earth standards.

801° fahrenheit

Littlefoot!

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