
Giant 'Great Valley' Found on Mercury - lucodibidil
http://thescienceexplorer.com/universe/giant-great-valley-found-mercury
======
nitrogen
_> "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?

~~~
ubernostrum
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).

~~~
tossaway1
Either way, the Mariana Trench seems to dwarf the valley that's described in
the article.

------
deepnotderp
Take that silicon valley ;)

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

------
module0000
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.

------
egfx
What's the temperature down there?

~~~
azernik
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.

~~~
egfx
"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...](http://www.slate.com/blogs/bad_astronomy/2012/11/29/_mercury_has_ice_buried_beneath_its_surface_in_craters_at_its_north_pole.html)

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

------
ktRolster
Littlefoot!

