Underground Ice on Mars Exposed by Impact Craters

Report: #0068

I like NASA's news more and more. This time, they show us – without warning or public pressure – images of new meteorite impacts on Mars.

Before getting to the main topic of this report, I want to highlight how the satellite technology over Mars never ceases to amaze me.  We don't know much about the satellites orbiting Earth or how they work. We watch the weather map every day without thinking too much that the forecast is the result of images taken by satellites and calculations based on transmitted data – like speed, cloud density, and temperature at different heights above Earth.

Other satellites create cartographic maps or help us not get lost – not in the woods or jungle, but in city streets.  GPS, increasingly common, is already integrated into phones so humble people – or those with little memory – can find the supermarket and return home safely. Young readers won't believe it, but old models – I mean people over twenty, even the few centenarian survivors – relied on their biological memory. They had to constantly recall the path from home to the factory, office, or cinema, and find the way back. Bars along the route saved many visitors by reminding them of the direction home. 

That was a bit of humor, but now I get serious – because this technology works perfectly on Mars. Remotely controlled satellites – that is, controlled from afar – can take images automatically but also receive precise instructions to photograph a specific location. 

This fact strikes me as surprising because everything is in motion: the satellite, Mars, the Sun, and the orders from NASA engineers transmitted via electromagnetic waves. Imagine: Only a small part of Mars is mapped, at least in high resolution.

Every image arriving from Mars is instantly studied by computers and visually – I don't know by how many people, possibly hundreds or thousands. Important images are analyzed by experts, and if they're highly relevant, the satellite is directed back to those exact coordinates.  That's the secret I don't understand. From discovery to radio instruction to the satellite, hours or days pass.

Everything is already in another place. How do you direct a satellite to an exact longitude in a precise orbit? Does a satellite have enough fuel to change course, turn, accelerate, or brake?

It must be so, because they won't wait to find that important spot by chance again.  I've already rambled a bit about satellites. Better to accept that it works when they want and forget the technical part. We can't know everything. That's what specialists are for – but as the word says, they don't know everything either, precisely because they're specialists. So we're even: each with our gaps and shadows, but also our brilliant knowledge.

NASA offers us today a piece of news that, for some humble researchers and observers, isn't entirely new – but it is new in the freedom with which they inform us: There is liquid water on Mars!

Without much noise or propaganda, it's published that there is ice in Mars's subsurface. I used the expression "liquid water"; they say "ice in the underground," which means "subterranean ice on Mars."

For young readers, it may not be so surprising, but for me, there's always a touch of irony. Before, talking about rivers – even dry ones – visible on Mars's surface from Earth was a joke.

It was also a joke to think of finding planets beyond the eight we have left – or at least those recognized as such.

Well, I swallow the irony, because truth arrives in drops, even if it rains hard.  Let's look forward – or rather, to Mars, our sister planet, increasingly similar to our Earth.

In recent months, they compared new images with others taken in the same spot months before. What a surprise! There were meteorite impacts – luckily not too large, small ones or fragments of larger meteors that broke into pieces before hitting Mars's surface. 

Here, before continuing, a question arises: Why does a meteorite break before colliding? Logically, friction with an atmosphere heats it until it explodes into several fragments. This indicates the presence of a dense atmosphere.  Finally, the meteorite impacted – and I arrive at the end of my report.

What's the main news, the revelation of these impacts? Just a few centimeters under Mars's surface, there is already frozen water.

With a gentle impact from a small meteorite that barely penetrates a meter into the surface, water finds its way and emerges. I've pointed out to my readers several times that life forms seek underground water with their roots in the depths. 

Now it's official: There is water on the surface – not just in Mars's bowels. Surely, there's much more down there. 

Here, I show you the map presented by NASA on its website. Below are the links to the original English page. I'll explain in my humble words what this map means.

It shows a chart of a specific place on Mars, with indicated names. Some acronyms, letters, and numbers mark five points of recent meteorite impacts where, moreover, liquid water emerged to the surface.

When the water rose, it brought with it elements from the subsurface, which we can simplify as "ground from below." Ice – or water – has a short life on the surface. We know that from when Phoenix sent us images of ice under its platform, which evaporated before it could analyze it in its oven.

Ice, wherever it is, doesn't "burn" easily. 

Coincidentally, in the same place where Viking 2 landed (marked on the map with the acronym VL 2), ice is also found. Viking 2 couldn't dig deep enough to confirm the presence of ice or water, though it was already suspected.

However, obtaining a positive result was impossible because the analysts themselves didn't believe their instruments and rejected the results, arguing the test was contaminated with Earth water.  The black dots, from 1 to 5, are the impacts.

http://www.nasa.gov/images/content/388643main_fig1_no_contours-600.jpg

The blue color indicates that, from one centimeter under the surface, there is frozen water. The red color points to a depth of about ten meters. Between one centimeter and ten meters deep, water exists.

On the map, different colors indicate the depth where the ice is found.

The map covers an area from 40 to 60 degrees north latitude and from 130 to 190 degrees east longitude. Estimates of the depth to water-ice come from a computer model and observations of the brightness and temperature of the surface. The model matches the ice-exposing crater observations by NASA's Mars Reconnaissance Orbiter and data from the neutron spectrometer on NASA's Mars Odyssey orbiter.

Analysis of the observations of ice-exposing fresh craters at sites 1 through 5, reported by Byrne et al. in a Sept. 25, 2009, paper in the journal Science, leads the paper's authors to calculate that if NASA's Viking Lander 2 had been able to dig slightly deeper than the 10-to-15-centimeter-deep (4-to-6-inch-deep) trench that it excavated in 1976, it would have hit water ice.

Image Credit: NASA/JPL/University of Arizona

The High Resolution Imaging Science Experiment camera on NASA's Mars Reconnaissance Orbiter took these images of a fresh, 6-meter-wide (20-foot-wide) crater on Mars on Oct. 18, 2008, (left) and on Jan. 14, 2009. Each image is 35 meters (115 feet) across. This crater's depth is estimated to be 1.33 meters (4.4 feet).

The impact exposed water ice from below the surface. It is the bright material visible in this pair of images. The change in appearance from the earlier image to the later one resulted from some of the ice sublimating away during the Martian northern-hemisphere summer, leaving behind dust that had been intermixed with the ice. The thickening layer of dust on top obscured the remaining ice.

Image Credit: NASA/JPL/University of Arizona

Material Excavated by a Fresh Impact and Identified as Water Ice

http://www.nasa.gov/images/content/388655main_site3.jpg

Here is another impact with the same effect: Water emerged from below, froze, and vaporized slowly. Bright ice under the sun on Mars's surface. A recent fact – in 2008! 

The bright material in this image was excavated from the subsurface and deposited nearby by a 2008 impact that created a crater about 8 meters in diameter. The extent of the bright patch was large enough for the Mars Reconnaissance Orbiter's spectrometer to confirm it was frozen water.  Image credit: NASA/JPL/University of Arizona  I thank NASA for these images and for their sincere declaration that there is water on Mars. 

Josef Bauer

Credit: http://www.nasa.gov/mission_pages/MRO/news/mro20090924.html