Mars rover Curiosity finds signs of ancient stream By ALICIA CHANG | Associated Press The NASA rover Curiosity has beamed back pictures of bedrock that suggest a fast-moving stream, possibly waist-deep, once flowed on Mars — a find that the mission's chief scientist called exciting.
There have been previous signs that water existed on the red planet long ago, but the images released Thursday showing pebbles rounded off, likely by water, offered the most convincing evidence so far of an ancient streambed.
There was "a vigorous flow on the surface of Mars," said chief scientist John Grotzinger of the California Institute of Technology. "We're really excited about this.
The other thing is that it could be NOT water but some other substance which turns to gas very quickly.
Something like a liquid under pressure when it emerges from the underground (or as part of a process), but as soon as it hits the outside, it turns into a gas. The only thing I can think of at the moment is "dry ice" or solid carbon dioxide which is heavier than air and floats about on the ground like mist.
There must be alcohol-like liquids which hit the heat of the outside and which almost immediately evaporate into the atmosphere.
The liquid shown in the nasa animation appears to flow out of the hills seasonally. Perhaps due to the desert climate it simply evaporates and/or seeps into the sand before large water bodies can collect.
"Nice question. Although pure water freezes at 0°C (32°F), water that has salt dissolved in it has to be colder before it freezes. If the water has as much salt dissolved in it as it can hold (that's called a saturated solution of salt), so that any further salt would just come out as crystals, the freezing temperature is around -21 °C, or about -6 °F. If your freezer isn't colder than that, the part of the ice touching the salt will start to melt. If you've put so much salt on the ice that the water can all melt and form a saturated solution, and still leave some salt crystals, then it will all melt. If you've put only a little salt on, it will melt some ice until the salt crystals are gone. Now as more ice melts the solution becomes less salty, more like pure water. So its freezing temperature goes up. At some point its freezing temperature will be the same as the freezer temperature, so the freezing will stop. You'll have some ice left, and some salty water. "
so we're talking 6F? 21C? from fresh water, lol!
really, does anybody else find this ludicrous? all water on mars is salty, that's what i am hearing from them.
and then the "hundreds of years old", what the heck, how would they even begin to guess?
Strange how they say that "water patterns appear to change with the seasons"... and then "Water streaks on Mars are thought to be hundreds of years old" I wish they would make up their minds and put out a clear message. Maybe this is so they can be 'wrong' about it later if necessary.
emphrasis below are mine.
The water shows up as dark colored finger like streaks flowing down from various slopes and crevices. Based on seasonal photos, the water patterns appear to grow or recede depending on the season. Scientists hypothesize that the briny water could appear and disappear based on the winter or summer months on the Red Planet.
"We expect water on Mars to be briny, to be salty, because we know that the surface is salty from all of the past landers and rovers...Furthermore, the salt serves to depress the freezing point of the water, so in places where it's below freezing, we see this activity, it is still plausible for that to be salty water," said Alfred McEwen of the University of Arizona.
The theory of Mars holding briny salty water is connected to its freezing point. The more salt water contains, the lower the freezing temperature. Based on McEwen's observations, the apparent unfrozen flowing waters were spotted on steeper slopes as it descends at warmer seasonal months. Water streaks on Mars are thought to be hundreds of years old.