A quick Mars timeline:<p>Mars was formed around the time Earth was, but it was blessed with only 11% of Earth's mass and less than 40% of Earth's gravity field. Shortly after cooling solid, its "Noachian Era" was similar to proto-earth: warm, a thick atmosphere, plenty of liquid water on the surface, and probably a significant magnetic field.<p>But this era was still during the era of the Late Heavy Bombardment, a time in which the last dregs of the solar system were still settling out. Large asteroids still pounded the planets with regularity.<p>Unlike Earth, Mars had trouble maintaining its liquid iron magnetic field. Since it's much smaller, it cooled and thus congealed faster. And there's growing evidence that asteroid impacts were able to drive enough heat beneath the surface that interior convection was quelled, leading to a fragmented magnetic field.<p>Without an adequate magnetic field to deflect solar wind, the atmosphere was prone to shedding off pieces of itself into space. This was amplified by the lower gravity which meant holding on to lightweight gasses was even harder.<p>Over time, Mars cooled to the point where the major forms of tectonics ceased. The water locked up beneath the ground, rusted out pulverized basalt dust from the asteroid impacts, and frizzled in the radiation-baked atmosphere, floating off.<p>The seas and lakes dried, the rain stopped, and that... was that.<p>Three billion years later, we arrive on the scene and find out we have a little sibling. Then we send robots. We hope to find life, or evidence that it once lived. Characterizing how water worked in the Martian past is a part of answering that question.
Not to burst anyone's bubble, but this is not the staggering news it's being made out to be. It is good foundational geology, yes, but water has essentially been confirmed for years now.<p>The story of Mars in short: flop planet, can't hydrosphere.<p>There is extremely strong evidence that in the very early years Mars was capable of holding on to a great deal of water: Enough to cover the Southern Hemisphere. The streambed seen here is from that time.<p>That downer is that this was over 3 billion years ago. Through a variety of processes and for a number of reasons most of Mars' water was lost to space or trapped underground.<p>The billion-dollar question that would be epic to answer: Did Mars develop Or acquire life during the time it had liquid water on the surface and if so is there any trace of it left, alive or dead?
<i>"... NASA's Curiosity rover mission has found evidence a stream once ran vigorously across the area on Mars where the rover is driving. There is earlier evidence for the presence of water on Mars, but this evidence -- images of rocks containing ancient streambed gravels -- is the first of its kind ..."</i><p>Why isn't this front page, the implications are staggering.
Out of the set of pictures I find this one the most intriging <a href="http://www.nasa.gov/mission_pages/msl/multimedia/pia16189.html" rel="nofollow">http://www.nasa.gov/mission_pages/msl/multimedia/pia16189.ht...</a><p>The cemented section on the mars side is in itself most interesting I find and yet seem unable to state why. Wonderous stuff indeed.
<i>"From the size of gravels it carried, we can interpret the water was moving about 3 feet per second, with a depth somewhere between ankle and hip deep," said Curiosity science co-investigator William Dietrich of the University of California, Berkeley. </i><p>Out of interest, how do we know it was water, and not some other liquid?
The real question is where did the water go and does it still exist somewhere on Mars? Finding a little bit of ice or water is one thing, finding an old streambed is another — but potentially finding an underwater ocean/ecosystem filled to the brim with undiscovered organisms makes me excited not only from a study of different organisms perspective but perhaps because the key to curing diseases that plague Earth might be found on Mars not to mention unlocking other discoveries like how to live longer and even more exciting finding organisms that don't age and have been alive since Mars was created.<p>My mind is teeming with excitement of the possibilities, is anyone else as excited as me?
No they didn't find a "streambed". They found a bunch of clasts, with pebbles that wind couldn't move. Perhaps they were moved by something solid rather than liquid. Perhaps that was some kind of ice.<p>It's tiresome hearing of the "piling evidence" for water on Mars. Find some damn water. Prove it by melting it then boiling it on camera in a container with a thermometer.