Geometry and Mars

I recently started receiving updates from Space.com.  The other day, there was an article on how they used geometry to figure out something about the water on mars.

If you look at closeups of Mars, you'll see something that looks like scars created by running water. Scientists have argued about where the water came from and where it went.

A group of scientists decided to use a statistical approach to determining where the water came from. 

They looked at the angle that those scars crossed each other.  The angles indicate if the area is dry and where the water might have come from.

They discovered the angles are fairly low, indicating the channels were not formed by ground water. In addition, the narrow angles of the valleys indicate a desert climate such as one found in Arizona.  Wider angles of the valley would indicate groundwater coming up from the ground.

The best theory is the channels were formed by sporadic heavy rainfalls over a long period of time.  The rain falls and runs off quickly creating a network of these valleys. 

At this point in time, there does not appear to be any water on the surface but scientists believe the northern hemisphere contained an ocean about 4 billion years ago. It is thought Mars had an atmosphere which allowed the planet to have a water cycle. 

As water evaporated, it condensed around the volcanoes in the southern hemisphere before raining down and carving channels in the planet.  Unfortunately, it appears the atmosphere only lasted a few hundred of millions years before the atmosphere is lost and water disappears.

This is not the first time scientists have used geometry to determine things in relation to Mars. Back in 2013, NASA's Mars Reconnaissance Orbiter discovered the sand dunes in a crater are in a polygon shape.  In addition, these types of sand dunes are fairly common but only in the bottom of craters and other low lying terrain.

The micro climates along with heating and cooling causes wind to blow in certain directions to form these polygon shaped sand dunes.  Furthermore, the dark sand appears to be from an iron rich basalt such as that found in Hawaiian volcanoes.  We do not have anything like this on Earth.

If you do a search on this topic, you'll find several different papers on using geometry to help explore certain facets of Mars.  I find it quite fascinating.  I actually attended a talk a couple years ago in which a scientist compared geologic formations on Mars with the same type of thing on Earth. 

Let me know what you think, I'd love to hear.