NASA has announced that the Curiosity rover has found evidence of a fast-moving stream that once flowed over the Martian surface. "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 …
Lots of unanswered questions though. I thought the pressure of the atmosphere basically meant that water couldn't exist on Mars for more than a few seconds. How has this fairly fundamental variable changed so that it was once possible to have streams of flowing water?
Anyone able to shed some light?
Dunno. But "we have found some gravel with vaguely rounded edges" doesn't instantly prove water to my satisfaction. But what do I know, I've only studied this stuff to first degree level.
The rocks were laid down billions of years ago when conditions were different. Exactly how they were different is what we're finding out from these observations. Presumably one of the changes was the loss of a lot of atmosphere.
I'm no expert, but I think Mars once had a decent atmosphere but something happened a long time ago to kill the planetary dynamo the provided the magnetic shield to stop the solar wind stripping that away. Now we see little of what was once there.
Remember Venus is the same (approx) gravity as the Earth, but has a *much* higher atmospheric pressure.
Hopefully some more expert commentards will provide you with enlightement...
Its a while since i did the planetary geology stuff (I've moved onto more local hydrocarbon exploration since), but in answer to the above;
The gravel is dense enough and rounded enough to prove transportation by a viscous medium.
Mars likely stopped its tectonism a long time ago, which meant it stopped producing gasses able to replenish the lossese to space. On earth, the serendipity of life - first anaerobic, then aerobic - created an atmosphere that sustains an atmosphere and, unlike Venus, is able to achieve equilibrium with solar energy.
Life may be present in this stream by NASA, but its more likely to be found in the places where he most basic life can develop, such as the clays and mineral rich sedimentary deposits thought to exist elsewhere in Gale crater. Proof of life doesn't need to be a fossil encased in gravel, just a complex amino acid or RNA which is unlikley to be formed through conventional physical chemical processes.
The really intersting science about Mars (for me at least) isn't the search for life - surely life can develop elsewhere, but it needs to be intelligent or terraforming (re: Earth) to be of interest - but the internal structure and understanding why tectonism stopped. This applies even more so for Venus.
Beer icon because you shouldn't write on t'internet after the pub....
Under current conditions liquid flowing water at the martian surface is indeed extremely unlikely, if not next to impossible. The atmospheric pressure is so low that for water the boiling point comes so close to the freezing point that there's next to no difference. The temperature is also so low that the only place water on the surface can become liquid at all would be at the equator during high summer.
Ancient Mars, however, did have an atmosphere that was (far) more dense, so that the boiling point of water would have been a lot higher, making liquid surface water quite possible, even if the pressure would have been as low as ,say, tip-of-mount-everest.
The planet itself would also have been a bit warmer than it is now, as the atmosphere would still have contained a fair amount of the greenhouse gases, including quite a bit of methane. So the atmosphere would have retained more of the sun's energy than it does now, and would definitely have contained quite a bit of the radiant heat of the surface, which was geologically quite active at the time.
The question is whether there was *enough* liquid water on Mars to create the high pressure + heat + chemicals environment needed to kickstart "life" , and whether this environment lasted long enough to allow for evolution of sufficient complexity to allow for adaptation and survival, so that any organism that could have existed would have had a chance to leave enough of a mark on the planet for us to actually see.
For Earth, the fossil evidence shows that the earliest bacteria were already around at 3.5*10^9, give or take a couple 10's of million, years ago. *If* there was sufficient liquid water on Mars to form anything like an ocean, the circumstances there would have been not unlike those on earth. For those very early lifeforms, they would probably have been quite similar, as they were chemotrophes, and not dependent on sunlight at all.
The real question is, who will be responsible for paying the patent fees to Apple?
Well done... and completely unpredictable and original. Ever thought of writing comedy for a living?
The magnetic field depends upon a molten core. It being smaller than Earth, the molten core cooled quicker and solidified.
I think there is a pretty good chance for Earth bacteria to have "contaminated" Mars, and of-course visa-versa. Material carried to Earth from Mars is rare, but not unheard of. Materials carried from Earth to Mars must be rarer still, but theoretically possible. I wish for an independent strain on Mars, but consider it unlikely.
"It being smaller than Earth, the molten core cooled quicker and solidified."
Extrapolating this logic, smaller portions of curry carry an increased risk of constipation.
Every knows the only possible explanation is that the Martians spent too much time running around in gas guzzling 'Martian Rovers' and the resultant emissions of Carbon-Dyed Oxhide destroyed the ecosystem.
And it was a waste of time sending a rocket there to prove it, since the science was settled by some bloke with shares in Vestas, long ago. We should have spent the money on a wind turbine instead.
And to think it was only a few decades ago that people who talked about the possibility of life on Mars were laughed at. Now who's laughing.
No one would have believed...
"Few men even considered the possibility of life on other planets and yet, across the gulf of space, minds immeasurably superior to ours..."
Re: Minds immesaurably superior to ours
..must be ten a penny in the Multiverse..
This is the beauty of true science : it is never settled, and new data can... no, WILL be taken into account to jeopardize existing beliefs.
How can they tell it was a river?
There's no shopping trolley or mattress.
Re: How can they tell it was a river?
Certainly, if it was a river, it proves there was no human-like life, else they should find traces of discarded beer cans or at least heavy metals from nuclear accidents.
Are you sure this is Mars?
That photo could pass as one of a section of the lane leading to my house!
Re: Are you sure this is Mars?
Have you checked where you left your house?
Re: Are you sure this is Mars?
Pretty certain that this is actually a cropped photo of Lester's back yard. The original photo undoubtedly shows a JCB and a newly dug well in the background.
Where are the El Reg units?
"...water was moving about 3 feet per second..."
What's that in linguine per fortnight?
Re: Where are the El Reg units?
42. Wasn't it obvious?
Is it just me, or...
or do those rocks look a bit like a demolished slab of concrete? :)
Re: Is it just me, or... Hahaha, your comment reminds me of...
Capricorn One, hahahaha, which i liked as a movie...
Re: Is it just me, or...
Its all they had in that old studio lot on Hollywood..
Keep the river on your right
And please, send some astronauts instead of these robots.
Re: Keep the river on your right
Astronauts are much tastier.
Excuse my ignorance.
But in a low gravity, low atmosphere environment wouldn't solid particulate matter exhibit some properties of liquid dynamics (as seen on Earth.) And lead to false positives like this?
Pebbles being blown around the surface would also display the same polishing as it would in water. Channels would form, etc.
Or am I being grossly ignorant?
Re: Excuse my ignorance.
Wind tends to produce ventifacts rather than smooth pebbles, as it polishes via sandblasting rather than rolls them around.
Presumably there are similar tell-tale differences in the pebble shape you get from fluidized sand and viscous liquid like water, oil, and mud.
Re: Excuse my ignorance.
Is it just me or do these pebble not look that much rounded to you too ? I would expect a piece of rock crumbling for any reason to look exactly like that.
Paris cos that's my level of expertise in matian geology.
Oh wait, that is sidewalk. And behind that rise...it's...it's...
YOU MANIACS! YOU BLEW IT UP!
Hold on now
Surely if there was water there then it would have been put there by God as part of some divine plan? Or is that just what they teach in American science lessons?
I have a stream at the end of my garden and what they photograph on Mars 100% is NOT a stream bed. It looks far more like a dinosaur footprint. Of course NASA "scientists" take the stance that dinosaurs don't even exist on Mars so of course they won't even see the evidence staring them right in the face. It's a stream...sure and I have a bridge to sell you.
I have a nice theory....
The "powers that be" decided that life had to start somewhere, so they chose our solar system and sowed all the right ingredients on all the planets in the hope that one of them would flourish and survive. We survived, the rest died off one way or another.
Re: I have a nice theory....
So, does it explain why brontosauruses are thin at one end, much much thicker in the middle, and thin again at the other end?
Looking for the wrong things
Worms travel deep underground. They're attracted by vibrations on the surface. Stay close to the protection of the rocks and avoid the deep dessert.
Re: Looking for the wrong things
Like a soft custard pie?
Re: Looking for the wrong things
National Lampoon called from 1984; they'd like their joke back...
Re: Looking for the wrong things
If you walk without rhythm you won't attract the worm.
dull facts x distance = staggering importance
This shit blows my mind!
We've put a billion pound nuclear powered science lab on wheels on another planet!
If fucking love science me!
Re: This shit blows my mind!
You are SarcasticRover and i claim my 5 Quatloos.
On Earth, it's almost axiomatic that nothing is ever really clean - no matter how thoroughly you kill 99.9% of germs, the little buggers come back in no time at all. Life seems to be everywhere, even if it's in the Antarctic ice and therefore not very lively.
I find it slightly unsettling that there's a possibility that Mars, and most planets, are technically "clean". That even if the rover found some water and hydrated the grotty stuff in the photograph, the resulting slurry would be more sterile than surgical instruments.
"...the water was... between ankle and hip deep"
Was that hip-deep to a Heliumite or to a Thark?
I have waded dozens of trout streams across North America and have yet to find one were the stream bed consisted of sharp angular gravel as shown in the photo. The majority of stream bed gravel is usually smooth and rounded. The stream, if there was one, could have only run for a few years. I suppose it could be the result of an extremely infrequent flood event.
For the Martian atmosphere to have vanished so abruptly is that it was in fact destroyed by an alien spacecraft.
Turns out that their calculations were off, they were supposed to decelerate to Earth re-entry velocity from about 1.2C because their engines were malfunctioning, but in the process the gravitomagnetic field from the hyperdrive "grabbed" a big chunk of the oxygen rich highly diamagnetic atmosphere and hurled it off into space.
Most of the (luckily primitive) Martian life was wiped out, a few microbes survived and seeded the Earth about 570MY ago when a meteorite similar to the one which wiped out the dinosaurs impacted Mars.
The spacecraft then jumped back into hyperspace based timewarp like a whipcrack.
The alien spacecraft later made an appearance in 1947 when it finally managed to emerge from hyperspace to crash into an unfortunately placed weather balloon associated with Project Mogul and then impacted the New Mexico desert just outside Roswell at about Mach 0.8, leaving numerous bits of cool alien technology and two somewhat intact alien corpses and one very much alive one.
Which survived until the late 1960's IIRC..
Re: "Which survived until the late 1960's IIRC"
Wrong. I saw a documentary not long ago and the alien, named Paul, was alive and well just a few months ago when it got recovered by its fellows after a long and tense pursuit.
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