Beta

×

Welcome to the Slashdot Beta site -- learn more here. Use the link in the footer or click here to return to the Classic version of Slashdot.

Thank you!

Before you choose to head back to the Classic look of the site, we'd appreciate it if you share your thoughts on the Beta; your feedback is what drives our ongoing development.

Beta is different and we value you taking the time to try it out. Please take a look at the changes we've made in Beta and  learn more about it. Thanks for reading, and for making the site better!

Martian Gullies Explained By ... Sand

CmdrTaco posted more than 4 years ago | from the well-thats-not-'as-much-fun dept.

Mars 97

eldavojohn writes "There's a lot of evidence that a very long time ago some fluid once flowed on Mars, but the primary evidence of water today — gullies inside craters — is explainable by a much less exotic reason: flowing dust and sand. It would now seem that the news from 2006 that NASA had found definitive evidence of flowing water on today's Mars needs to be comprehensively reexamined. The Bad Astronomer lays claim that flowing sand and dust doesn't explain all recent hi-res imagery from the red planet, but it certainly does seem more plausible, considering what we know about Mars."

cancel ×

97 comments

Sorry! There are no comments related to the filter you selected.

YEAH RIGHT! (3, Funny)

Gerafix (1028986) | more than 4 years ago | (#32086290)

That's what the Martians want us to think. Next they're going to try and contaminate our precious bodily fluids.

Re:YEAH RIGHT! (2, Insightful)

mu51c10rd (187182) | more than 4 years ago | (#32086970)

to try and contaminate our precious bodily fluids.

We do that well enough ourselves already...no need for Martians to bother.

This is an incredibly important and urgent issue. (1, Funny)

Anonymous Coward | more than 4 years ago | (#32088068)

I think when we determine, once and for all, that there is or is not water on Mars, then all of human suffering will come to an end. I propose that we increase taxes and spending to their very limits so that we resolve this crisis as rapidly as possible. We should divert all available resources to this matter, including seizing all ore mines and drafting of engineers to support the program. Anyone who shows any potential to be able to do math or computer science should be taken from whatever it is they are doing now and put into training for this endeavor. The people living everywhere from Compton to Harlem; East Oakland to Washington D.C., will rejoice at the wonderful benefits of having finally solved this issue, and for sure will give up all their humble possessions and dreams of escape to a better community to support this effort. In fact, we should declare war; shut down all private industry; seize all assets and take whatever additional measures necessary. A few several-billion dollar programs are not enough. We need massive spending in this area to complete this task so crucial to the very survival of the human race. Contact your Congressman NOW and DEMAND ACTION!

Re:This is an incredibly important and urgent issu (1, Funny)

Anonymous Coward | more than 4 years ago | (#32088580)

Is it hard posting to Slashdot while volunteering at the soup kitchen?

Re:This is an incredibly important and urgent issu (0)

Anonymous Coward | more than 4 years ago | (#32102610)

No soup for you!

Re:YEAH RIGHT! (1, Funny)

Anonymous Coward | more than 4 years ago | (#32087000)

On no account will a Martian ever drink water, and not without good reason.

Re:YEAH RIGHT! (1, Funny)

Anonymous Coward | more than 4 years ago | (#32089044)

That's what the Martians want us to think. Next they're going to try and contaminate our precious bodily fluids.

Too late! They already have floridated the water!

Re:YEAH RIGHT! (1)

mjwx (966435) | more than 4 years ago | (#32094138)

That's what the Martians want us to think. Next they're going to try and contaminate our precious bodily fluids.

What makes you think we want your fluids monkey. We have already abducted the one designated Paris Hilton and have sequenced the DNA of half your race.

Oh yeah? (3, Funny)

clang_jangle (975789) | more than 4 years ago | (#32086300)

Oh yeah, smart guy? Then answer this:

WTF do the Martians drink?

Re:Oh yeah? (2, Informative)

StripedCow (776465) | more than 4 years ago | (#32086378)

simple: sand

Re:Oh yeah? (1)

Captain Spam (66120) | more than 4 years ago | (#32086386)

Sand, obviously.

Re:Oh yeah? (0)

Anonymous Coward | more than 4 years ago | (#32086436)

Salt. It's got electrolytes.

Re:Oh yeah? (1)

Hordeking (1237940) | more than 4 years ago | (#32089134)

Salt. It's got electrolytes.

Isn't that what Brawndo is made of?

Re:Oh yeah? (1)

Jeng (926980) | more than 4 years ago | (#32086982)

I would imagine that any liquid there must be rather saturated with iron and other metals, salts, and enzymes.

There may be a good chance that our blood could be a good substitute for the liquid that is native to their environment.

In short, the Martians want to drink our blood.

Re:Oh yeah? (1)

bregmata (1749266) | more than 4 years ago | (#32087036)

Single malt whiskey, and only single malt whiskey.

Re:Oh yeah? (1)

Mindcontrolled (1388007) | more than 4 years ago | (#32087146)

You mean pure grain alcohol and nothing but pure grain alcohol? K'Breel told my that they care very much for the purity of their bodily fluids.

Re:Oh yeah? (2, Funny)

blair1q (305137) | more than 4 years ago | (#32088968)

Explains their tendency to abduct hillbillies.

Re:Oh yeah? (1)

TSRX (1129939) | more than 4 years ago | (#32089362)

Would this be a "No True Martian" fallacy?

Gatorade (1)

7bit (1031746) | more than 4 years ago | (#32093040)

Gatorade - It's what Martians crave!

Hi-Res Imagery (4, Funny)

Monkeedude1212 (1560403) | more than 4 years ago | (#32086322)

Have they found the soundstage on mars where they faked the moon landing?

Re:Hi-Res Imagery (-1, Offtopic)

Anonymous Coward | more than 4 years ago | (#32086606)

I found a landing strip on a drunk skank that mooned me.

Re:Hi-Res Imagery (0)

Anonymous Coward | more than 4 years ago | (#32088082)

Mythbusters episode 104.

Re:Hi-Res Imagery (0)

Anonymous Coward | more than 4 years ago | (#32088990)

I think you missed the joke my friend.

Have they found the soundstage on mars where they faked the moon landing?

This joke relies on the idea that it takes much more to get to Mars than to the moon.

Also, it's an XKCD reference, but I can't be arsed to find the specific link at this time.

Terraforming (1)

bluefoxlucid (723572) | more than 4 years ago | (#32086332)

Water, microbes, can we fill it with CO2, no ionosphere, how do we colonize...

Seriously. The only way to deal with Mars is to divert the asteroid belt's mass towards it to increase its mass. Force several tens of thousands of asteroids into a decaying orbit such that the mass is deposited on the planet. There's no water there, it all evaporates away without enough gravity to hold an atmosphere and enough pressure to remain liquid!

Re:Terraforming (4, Interesting)

heck (609097) | more than 4 years ago | (#32086440)

The only way to deal with Mars is to divert the asteroid belt's mass towards it to increase its mass. Force several tens of thousands of asteroids into a decaying orbit such that the mass is deposited on the planet. There's no water there, it all evaporates away without enough gravity to hold an atmosphere and enough pressure to remain liquid!

Mass is not the issue; the lack of a magnetosphere is. Without a magnetosphere, the solar wind will strip the atmosphere, leaving you in the same state. We would need to provide some means of creating a field which shields the atmosphere from solar winds.

Did a quick google to find an article - this one was published in 2010: http://science.nasa.gov/science-news/science-at-nasa/2001/ast31jan_1/ [nasa.gov]

Re:Terraforming (1)

heck (609097) | more than 4 years ago | (#32086484)

Yes I meant 2001. Crap. (Um, intentional reference to two of Arthur C Clarke's works. Yeah, that's it!)

Re:Terraforming (1)

roman_mir (125474) | more than 4 years ago | (#32087692)

Magnetosphere is easy, all you need to do is

Re:Terraforming (2, Interesting)

Brett Buck (811747) | more than 4 years ago | (#32087770)

Well, if you crash a bunch of asteroids into it, it will likely become molten, creating a new phase of differentiation, and there is a reasonable chance that a new dynamo will form and create a new magnetosphere. It's at least as plausible that that would happen as you could crash a bunch of asteroids into it in the first place. It wouldn't likely last all that long in geological terms given the likely lack of useful radionuclides.

Re:Terraforming (1)

GrumblyStuff (870046) | more than 4 years ago | (#32089542)

If you can move that much material around space, you could alter the orbit of Mars to bring it closer to Earth. Ok, that still wouldn't help with the magnetosphere but once you're moving planets, you can hollow them out and have a roaming planetship.

Re:Terraforming (0)

Anonymous Coward | more than 4 years ago | (#32087902)

So if solar wind strips away the atmosphere of a planet with no magnetosphere, how come the atmosphere of Venus is so thick?

Re:Terraforming (2, Interesting)

heck (609097) | more than 4 years ago | (#32088710)

So if solar wind strips away the atmosphere of a planet with no magnetosphere, how come the atmosphere of Venus is so thick?

Venus has an induced magnetosphere, created by an ionized layer in the ionosphere. That said, it is theorized that 4 or 5 billion years ago Venus used to have more liquid water on the surface and in the atmosphere, and over time that many of the lighter gases (such as water vapor) have been blown away by the solar wind, and those gases continue to be blown away, resulting in the atmosphere we see today.

As I said earlier, for Mars to have an atmosphere including water vapor, some protective layer would have to be created. I should have been clearer and stated it did not have to be a magnetosphere.

Re:Terraforming (1)

SliceofPi (1495453) | more than 4 years ago | (#32089062)

So, why don't we consult Kuato who can creepily tell us "Free your mind!" and point us toward the Alien Artifact that can save Mars. We can tunnel beneath the Martian surface, restart the Alien Artifact and melt the underground ice caps resulting in massive water vapor.

Sounds plausible..

Re:Terraforming (1)

theArtificial (613980) | more than 4 years ago | (#32089658)

Nit pick "Open your mind, Quade!". "Free your mind" is The Matrix.

See you at the party Richter!

Re:Terraforming (2, Interesting)

Golddess (1361003) | more than 4 years ago | (#32089288)

http://en.wikipedia.org/wiki/Venus#Magnetic_field_and_core [wikipedia.org]

Huh, so it does. I mean, I'm not the AC, I figured it had a magnetosphere, but thought it was due to having a molten core like Earth.

A quick skim of the wiki link doesn't seem to mention anything about it, but I seem to recall hearing about Venus' molten core with regard to the planet having periodic planet-wide catastrophic volcanic explosions because the lack of plate tectonics does not offer a more gradual pressure release system like on Earth.

Re:Terraforming (1)

sznupi (719324) | more than 4 years ago | (#32102880)

And those resurfacing events possibly have their part in replenishing the atmosphere. Plus the lack of plate tectonics is itself related to the initial inability of Venus to retain its water...

Generally, it seems the Earth was just barely a big enough planet to remain hospitable to organic life.

Re:Terraforming (1)

Monkeedude1212 (1560403) | more than 4 years ago | (#32086458)

I think one of the bigger issues is that Mars doesn't have a molten core, and therefor, not much of a magnetic field. We already know that Nuclear reactions can cause bad radiation, and that the core of the sun is constantly going through nuclear reactions. As such, a lot of radiation gets shot towards Earth, but because our planet has a magnetic field a lot of it gets reflected or refracted away. This is what causes the Northern lights.

So, I mean, should we get air on Mars, we'll still probably get bombarded with Beta Particles.

Re:Terraforming (1)

Yvan256 (722131) | more than 4 years ago | (#32086694)

So, I mean, should we get air on Mars, we'll still probably get bombarded with Beta Particles.

But that would be a perfect place to build a super-heroes training camp!

Re:Terraforming (1)

mbone (558574) | more than 4 years ago | (#32089546)

I think one of the bigger issues is that Mars doesn't have a molten core,

Mars does have a molten core, which was shown by the combination of Viking and Pathfinder [harvard.edu] tracking data.

I am pleased to say that I helped get make those finding possible, by going to various people at JPL with a colleague (Bruce Bills) and pressing all and sundry to get the DSN to range to Pathfinder after landing, specifically to improve the precession constant and determine this.

Re:Terraforming (1)

mbone (558574) | more than 4 years ago | (#32089648)

not much of a magnetic field

Well, that is an interesting point. It has a liquid core. It has a fair amount of magnetization of its surface [usra.edu] .

So, it had a magnetic field, presumably from a core dynamo like the Earth's. To me, the question is, did the core dynamo die some long time ago, or is Mars currently undergoing a magnetic field reversal, as the Earth does regularly (i.e., was had a billion years ago, or a few thousand) ? The vast consensus is that the Mars magnetic field died a long time ago, but I think it is more provocative to hypothesis an ongoing field reversal, and see what observables could come from that.

Re:Terraforming (1)

sznupi (719324) | more than 4 years ago | (#32102810)

Don't equate nuclear reactions = bad radiation so readily in this case. Photons which start as gamma rays in the Sun core are in the spectrum around visible light when finally emitted towards us. Sure, also quite a lot of UV there...but that's not the most problematic element of "space radiation".

That would be the stream of energetic particles; "solar wind". Mostly a result of good old heating and interactions with magnetic fields in the solar atmosphere.

Re:Terraforming (1)

Gerafix (1028986) | more than 4 years ago | (#32086634)

Why do we have to live on the surface? Let's move in underground, should be plenty of room and my impression is the geology is fairly stable although I could be wrong.

Re:Terraforming (4, Informative)

CrimsonAvenger (580665) | more than 4 years ago | (#32086854)

The only way to deal with Mars is to divert the asteroid belt's mass towards it to increase its mass.

If the entire Belt were diverted to Mars, it would increase Mars' mass by about 1%.

In other words, "your idea is silly"....

Re:Terraforming (1)

Jeng (926980) | more than 4 years ago | (#32089076)

Well darn.

How much could we increase it if we started sending Kipper belt objects at Mars?

Re:Terraforming (1)

tibit (1762298) | more than 4 years ago | (#32089256)

I'm sure the herring would not appreciate that!

Re:Terraforming (0)

Anonymous Coward | more than 4 years ago | (#32097546)

Go read "Mining the Oort" or "The Barsoom Project" -- both deal with this idea to whatever extent.

It's a good idea -- basically after we establish that there's no extant life on Mars and before we start colonizing it, bombard it with comets from the oort cloud to build up the atmosphere.

Re:Terraforming (1)

d1r3lnd (1743112) | more than 4 years ago | (#32097898)

Hey guys, let's take the most easily accessible resources in the solar system and then drop them into the giant fucking gravity well of a planet we don't live on.

Awesome plan, dude.

Re:Terraforming (1)

bluefoxlucid (723572) | more than 4 years ago | (#32100728)

The most useful resources there are nickel-iron, made of two highly common elements easily mined on earth for cheap.

Re:Terraforming (1)

d1r3lnd (1743112) | more than 4 years ago | (#32102280)

Easily mined on Earth. Not easily hauled into orbit for space-based industry.

Sad But No Biggie (1)

sonicmerlin (1505111) | more than 4 years ago | (#32086420)

It's a shame that our evidence for water turned out to likely be false, but that shouldn't stop us from continuing to look. We're not going to be travelling to Mars until at the earliest the '30s, so there's no real rush.

Re:Sad But No Biggie (4, Insightful)

Anne_Nonymous (313852) | more than 4 years ago | (#32086482)

Forget water. If you want to create a space stampede to Mars, announce the discovery of oil there.

Re:Sad But No Biggie (0)

Anonymous Coward | more than 4 years ago | (#32087032)

Didn't work for Titan.

Re:Sad But No Biggie (0)

Anonymous Coward | more than 4 years ago | (#32088092)

Well, Titan is more "liquid methane" than "oil", but hydrocarbons are hydrocarbons, I guess.

Re:Sad But No Biggie (2, Insightful)

JoshuaZ (1134087) | more than 4 years ago | (#32094034)

Well, that would make scientists ecstatic also. Oil means there was life in the past. Enough life to produce oil would upset a lot of models and make things very interesting. I doubt that the discovery of oil on Mars would actually cause industry to be that much more interested than they would be now. The energy cost of moving the oil back to Earth would probably be much larger than that gained from getting the oil. I'm not even sure it would make industry much more practical on Mars since there's not much oxygen on Mars that you can use to burn the oil there.

Re:Sad But No Biggie (1)

Hurricane78 (562437) | more than 4 years ago | (#32095130)

Do you realize the implication of oil being there? That would mean that once there was life there! ^^

Re:Sad But No Biggie (1)

sexconker (1179573) | more than 4 years ago | (#32086964)

We're not going to be travelling to Mars until at the earliest the '30s, so there's no real rush.

"The '30s"?
I'm with you as long as we can bring back some slang from the 1930s.

Rube.
Trolly.
Aces.
Heater.
Murder.
Ring-a-ding-ding.
Kibosh.
Skin tickler.
Folding green.

http://www.paper-dragon.com/1939/slang.html [paper-dragon.com]

Even if it were there, big question. (1)

RyuuzakiTetsuya (195424) | more than 4 years ago | (#32086584)

Is it potable?

I know that was the entire basis for one of the Doctor Who specials, but, do we even know how hard it would be to make it potable where it not to be drinkable?

Re:Even if it were there, big question. (1)

blair1q (305137) | more than 4 years ago | (#32089004)

Potable?

Dude. 4/20 day was like a week ago. Snap out of it.

Just get better info (5, Funny)

SnarfQuest (469614) | more than 4 years ago | (#32086632)

Take those photos that the various missions have taken of Mars, and use the photo analysis software that CSI uses. You should be able to look at things down to a molecular level then. Even a photo taken with a disposable camera that happened to be pointing in the direction of Mars during a stormy night should be sufficient to determint the location of all water on Mars. They could look at the back side of Mars based on a reflection from one of the stars behind it, so you should easily have 360 degrees of visibility..

What we know about Mars (5, Funny)

Yvan256 (722131) | more than 4 years ago | (#32086658)

Nutrition Facts: Mars Bar

Calories: 220
Sodium: 70 mg
Total Fat: 9 g
Potassium: 0 mg
Saturated: 6 g
Total Carbs: 36 g
Polyunsaturated: 0 g
Dietary Fiber: 1 g
Monounsaturated: 0 g
Sugars: 30 g
Trans: 0 g
Protein: 2 g
Cholesterol: 5 mg
Vitamin A: 0%
Calcium: 6%
Vitamin C: 0%
Iron: 4%

Percent Daily Values are based on a 2,000 calorie diet. Your daily values may be higher or lower depending on your calorie needs.

Re:What we know about Mars (1)

DarthBling (1733038) | more than 4 years ago | (#32087384)

Iron: 4%

Hmm, I thought the iron content would of been higher for Mars.

Re:What we know about Mars (0)

Anonymous Coward | more than 4 years ago | (#32088364)

would HAVE been

Re:What we know about Mars (1)

jrpubpro (1568791) | more than 4 years ago | (#32088632)

OK then, no water...

Re:What we know about Mars (1)

Hurricane78 (562437) | more than 4 years ago | (#32095354)

I didn’t know that a Mars bar is 4% iron.

Still not enough to replace my favorite morning cereal: Gravel and nails.

Greets,
Chuck

Photo of water on mars. (3, Informative)

molo (94384) | more than 4 years ago | (#32086782)

The ESA already has a picture of water ice in a martian crater. Maybe they are talking about different types of craters in different regions, but this photo clearly shows that it is possible.

http://www.esa.int/SPECIALS/Mars_Express/SEMGKA808BE_0.html [esa.int]

-molo

Re:Photo of water on mars. (1)

2gravey (959785) | more than 4 years ago | (#32087510)

Dude, we know there is ice on Mars. They already found the ancient Martian reactor that turns it into oxygen.

Re:Photo of water on mars. (1)

blair1q (305137) | more than 4 years ago | (#32089026)

Are you sure that really happened?

Check your credit statements.

Re:Photo of water on mars. (0)

Anonymous Coward | more than 4 years ago | (#32087572)

THIS.

There was even a GIF of ice melting in the sunlight from the 2 rovers from NASA, as well as several pictures of very obvious water trickle tracks around it.
Those were no rock or stone tracks.
There were only a small number of frames from it though.

It was literally right next to the rover.
Anyone remember where it was? I can't, it was a while back now.

no water no life no nothing ..... (1)

noshellswill (598066) | more than 4 years ago | (#32086866)

That's right wiener_dudes. No water on Mars. Ever. No life ... ever. No nothing. Here, but not there. No Princess Lea no sandworms. It's empty pals ... our solar-system and galaxy. All the universe is empty except earth of everything but horror. Just us. Alone. Always.

Re:no water no life no nothing ..... (2, Insightful)

Colonel Korn (1258968) | more than 4 years ago | (#32087062)

That's right wiener_dudes. No water on Mars. Ever. No life ... ever. No nothing. Here, but not there. No Princess Lea no sandworms. It's empty pals ... our solar-system and galaxy. All the universe is empty except earth of everything but horror. Just us. Alone. Always.

Um...this article is talking about _some_ of the evidence for _recent_liquid_ water being called into question. There's a vast amount of solid water on Mars now and there's no question at all about that.

So to rephrase for you: HUGE amounts of water on Mars. Right now. Unquestionably. Solid water plus definitely active at one time volcanoes = definite liquid water. Life? Maybe, maybe not.

Re:no water no life no nothing ..... (3, Interesting)

meerling (1487879) | more than 4 years ago | (#32087694)

You don't read the science news stuff very often (or ever), do you...
NASA has definitely found water on Mars already.
They also found a number of minerals in the rocks that can only form in water, as far as we know.
True, that as far as we know bit means it could be something else, but let's stick with known laws until we have evidence of something else before jumping of the cliff labeled "It's got to be caused by an unknown means". Don't forget Occam's Razor. (Especially when the alternative is trying to choose between Known Science and Baseless Denials.)

Does this mean the dust & sand thing is wrong? Not really, but it doesn't mean that water is out either. Funny thing about places that change environments, their primary methods of erosion change as well. Just look at Egypt over the past 30,000 years as a small example.

Thanks

Re:no water no life no nothing ..... (1)

ColdWetDog (752185) | more than 4 years ago | (#32090038)

It's got to be caused by an unknown means". Don't forget Occam's Razor.

FTFA:

That is certainly not what you expect from solid material like sand flowing downhill.

Silly researchers. Any dude could tell you that those tracks are made by snowboards, err sandboards. Not a whole lot of things for those guys to do, but you've got give those Martian kids some credit: flying down the dunes looks like fun!

Re:no water no life no nothing ..... (0)

Anonymous Coward | more than 4 years ago | (#32093748)

Anybody notice that the research has not been published in a peer-reviewed venue?

Re:no water no life no nothing ..... (0)

Anonymous Coward | more than 4 years ago | (#32095586)

NASA has definitely found water on Mars already.

Reference please. Every claim I've read of water on Mars has been carefully hedged. Many have been withdrawn (like this one may be) due to new understanding.

They also found a number of minerals in the rocks that can only form in water, as far as we know.
True, that as far as we know bit means it could be something else, but let's stick with known laws

You've got to be kidding me! You're talking about the "known laws" of rock formation?! Are they like the laws of weather?

Don't forget Occam's Razor. (Especially when the alternative is trying to choose between Known Science and Baseless Denials.)

Do you also believe that the existence of life on Mars has been definitively proven because of the microsopic fossils on a Martian meteorite? Or were you already convinced by the canals? Or the giant carved rock face? You need to learn a little skepticism.

nasa FOUND water on mars already! (2, Funny)

AlgorithMan (937244) | more than 4 years ago | (#32086984)

http://antwrp.gsfc.nasa.gov/apod/fap/image/0504/WaterOnMars2_gcc_big.jpg [nasa.gov] this was really published by NASA a couple of years ago... on April 1st...

Re:nasa FOUND water on mars already! (1)

Hurricane78 (562437) | more than 4 years ago | (#32095154)

Sorry, I don’t follow links, that have “fap/image” anywhere in their name. Especially if they come from NASA. ;)

P.S.: (I prefer videos. ;)

"You keep using that word" (3, Interesting)

ErikTheRed (162431) | more than 4 years ago | (#32087224)

This actually hits on one of my personal bugaboos - scientists that claim to know something "definitively" while the research or hypothesis is still warm from the metaphorical oven. Unfortunately, the institutions that employ them have figured out that you can get funding through "science by press release" - the initial press release gets the headlines; the retractions are hardly noticed (except on Slashdot). The scientists themselves are certainly culpable as well for going along with this - they should know better. Only a small percentage of theories stand the test of time. Yes, I understand that it's 2010 and we all want answers right now, dammit, but 99.99% of the time life just doesn't work that way.

So anyway, "definitively" - You keep using that word. I do not think it means what you think it means.

Re:"You keep using that word" (2, Funny)

MathiasRav (1210872) | more than 4 years ago | (#32088208)

They're definitely doing it on purpose.

Re:"You keep using that word" (1)

rodarson2k (1122767) | more than 4 years ago | (#32088294)

The scientists don't write the press releases. They dont exercise editorial oversight, they don't choose the headline. That's the science press, and they are to blame.

Now, some scientists do get quoted for making statements that are too strong, but the press is like the National Enquirer: If they can't get you to make some ridiculous claim, they will find someone who is desperate enough to do so.

The solution: Don't read science press releases or newspaper articles - read the actual peer-reviewed articles. The kind of articles that nearly get rejected for being 'tempted to speculate'. (Oh, you mean that's too boring for you? You can't have it both ways.)

Re:"You keep using that word" (1)

H0p313ss (811249) | more than 4 years ago | (#32088518)

The scientists don't write the press releases. They dont exercise editorial oversight, they don't choose the headline. That's the science press, and they are to blame.

Which makes me wonder what the comparative rate of alcoholism is between scientists whose research is (badly) publicized and those which are not.

Re:"You keep using that word" (4, Insightful)

Chris Burke (6130) | more than 4 years ago | (#32088598)

This actually hits on one of my personal bugaboos - scientists that claim to know something "definitively" while the research or hypothesis is still warm from the metaphorical oven.

And one of my personal bugaboos is people getting their panties in a twist over scientists claiming something that they're not and never have actually claimed.

The word "definitive" appears nowhere except in this slashdot summary. It does not appear in the previous slashdot summary that the offending word links to, nor does it appear in the article that slashdot summary links to either, and certainly does not appear in the original statement by the scientists. In fact, the article says that more work needs to be done to determine if what they discovered was definitely water.

So basically your whole rant about "science by press release" is baseless slander because you assumed a word in a /. summary twice removed from the original source was the actual word used by scientists, rather than click a couple links and learn that you were wrong.

Good job.

Re:"You keep using that word" (1)

bit01 (644603) | more than 4 years ago | (#32091882)

"If this was coming down the slope [toward you], you'd want to get out of the way," said NASA's Kenneth Edgett, a scientist with Malin Space Science Systems. "This is the squirting gun for water on Mars"

And numerous other similar comments by the scientists involved.

So basically your whole rant about "science by press release" is baseless slander

Actually, it's the "scientists" who should be reprimanded.

In fact, the article says that more work needs to be done to determine if what they discovered was definitely water.

One cop-out sentence at the end of the article does not somehow make it okay when the basic thrust of the article was the exact opposite.

Some people love to put obscure modifiers in the small print and pretend that that justifies a dishonest main article/ad/whatever. It doesn't.

---

How many million manhours has the unsolicited advertising industry cost today?

Re:"You keep using that word" (1)

Chris Burke (6130) | more than 4 years ago | (#32092066)

And numerous other similar comments by the scientists involved.

Yeah like "water seems to have flowed".

One cop-out sentence at the end of the article does not somehow make it okay when the basic thrust of the article was the exact opposite.

Some people love to put obscure modifiers in the small print and pretend that that justifies a dishonest main article/ad/whatever. It doesn't.

It wasn't at the end of the article, it wasn't small print, it was right in the middle of the article and you know it. And there's nothing obscure at all about saying further work needs to be done to confirm their observations. "Certain tasks remain... to prove that it is definitely water." What the fuck is obscure about that plain English? Nothing. What's dishonest about saying you have strong evidence for something, but more work remains to confirm it? Nothing. That's good science.

Your protests, on the other hand, are dishonest and have nothing to do with science or its proper execution.

Re:"You keep using that word" (2, Informative)

DM9290 (797337) | more than 4 years ago | (#32088644)

The original press release did not say anything about "definitive" evidence of water. In fact it said:

"Certain tasks remain, according to the panelists. For example, a spectrographic analysis of the “white stuff,” to prove that it is definitely water. These might be carried out by the Mars Reconnaissance orbiter, recently arrived in order to replace the aging Global Surveyor.
"

So the original report said something looks like water. It isn't just a flow of dust.

And the current summary is WRONG. The new article also agrees that it is NOT simply flowing dust and sand.

"There is another possibility, however. Perhaps the gullies are caused by the flow of sand and dust. Similar gullies are known to occur on dunes on Earth but only when the angle of the hillside is above some critical threshold. The trouble with Martian gullies is that most of the hillsides are not steep enough for this process to occur."

The actual new proposal is this:
"Their idea is that the gullies are formed when carbon dioxide in the ground sublimates, causing the sand to become fluidised."

This actually AGREES with the original report that said :

“These things appearing bright is extremely unusual,” said to NASA panelist Michael Malin, explaining why NASA believes the apparitions are water, not mere avalanches of dust. “In the past, the things we’ve seen are very dark this requires some kind of fluidizing agent.”

So.... rather than contradicting ANYTHING that the original press release said this new information is merely another possible explanation for the surface feature.

This brings us back full circle to:

"Certain tasks remain, according to the panelists. For example, a spectrographic analysis of the “white stuff,” to prove that it is definitely water. These might be carried out by the Mars Reconnaissance orbiter, recently arrived in order to replace the aging Global Surveyor.
"

Re:"You keep using that word" (2, Interesting)

B1oodAnge1 (1485419) | more than 4 years ago | (#32088992)

The more time I spend in college the more I realize that nearly everything that we "know" is really just semi-educated guesses.

In my experience this applies to just about every science except perhaps math.

Re:"You keep using that word" (1)

Marble1972 (1518251) | more than 4 years ago | (#32096360)

Roger that...

Terminiology & Reccommended Reading (3, Informative)

SpaceMika (867804) | more than 4 years ago | (#32087544)

I love that "above some critical threshold" is listed like a mysterious or complex thing. It's the angle of repose, the angle that a material naturally sits at when you let it fall from a height and pile up. It might be, if things are very complicated, the angle of repose + cohesion, but then you're back at water-based theories again since water is the easiest way to remove cohesion and trigger failure.

I also really like that the experimenters managed to recreate a sand flow in their lab. Of course they did. The field of prior research involving laboratory sand flows is immense, especially if you start including the ones with tiny glass beads of carefully varied diameters instead of sand. The only problem is thioxtropy -- landslides are renowned for having material that exhibit viscosity inversely proportional to velocity -- which is not easily replicable in small-scale lab settings.

I'm not sure if this is a, "Physicists discover what geologists already knew" moment, or a "Journalists are puzzled by the mundane mysteries of science," or what, exactly, but if you want to learn more about landslides on Mars, check out geotechnical journals starting with Lucchitta 1978 (Bulletin of the Geological Society of America, v89, pg 1601) and work your way forward. As the lunar and Martian landslides discredited an entire set of excess mobility theories, they're very well described and discussed.

Re:Terminiology & Reccommended Reading (1)

blueg3 (192743) | more than 4 years ago | (#32089328)

The journalists read or had described to them the research, and arbitrarily picked (based on what seemed interesting or novel to them) parts to talk about. Science journalists rarely have any real understanding of which parts of research are actually novel and which aren't. Of course, they can repeat (badly) the summary "what these results mean", but when talking about the methodology, unless the scientist is careful to point out which parts are novel, they never get it right. Since a lot of the more interesting techniques are already well-understood, journalists will repeat those and phrase them as if they're novel.

Not that I have firsthand experience with this and am bitter about it.

That's a bit dissapointing (1)

quantumpineal (1724214) | more than 4 years ago | (#32087666)

How come every announcement by NASA has you going away saying 'Ah Well." Should be called NAWA

Martian Water (4, Informative)

mbone (558574) | more than 4 years ago | (#32088032)

From the original blog post : "over this timescale, the Martian atmosphere has been too cold and thin for liquid water."

I read something like this frequently, and yet it is simply wrong and I wish people would stop repeating it.

Liquid water is not magic, but governed by physics. For there to be liquid water on Mars, all that is needed is that water be present, that the surface pressure be above the triple point of water, and that the temperature be above the freezing point. (Actually, this can be relaxed somewhat for brines and the like, but let's put that aside for the moment.) We know that Mars has water. What about the other two conditions ?

Much of the surface of Mars is above the triple point of water (i.e., at a low enough elevation that the surface pressure is higher than 611.7 pascals). Any low lying region is. The Viking 2 landing site is (some of the time) and the Phoenix landing site is (all of the time). The entire Hellas basin is, and it is highly likely to have liquid water at times (as the surface temperature there is warm enough during the day). Remember, peak surface soil temperatures on Mars can reach 27 C, even under current climate conditions.

Further, the atmospheric pressure on Mars varies greatly during its obliquity cycle, and it is highly likely that the entire planet (except for the high volcanoes of Tharsis) can support liquid water at times during each obliquity cycle. During those phases of the cycle, the atmospheric temperatures will be generally warmer, as well.

Now, this does not prove or disprove that these gullies are formed by water rather than sand, but you don't need unusually strong brines or geothermal vents to have liquid water on Mars (even though both of those probably exist as well), and it is quite reasonable to expect its presence in places, even under current atmospheric conditions.

Re:Martian Water (4, Interesting)

SpaceMika (867804) | more than 4 years ago | (#32089036)

I share your exasperation with the lack of popsci understanding of Mars' variable temperatures & pressures.

When I used to run planetarium shows for kids, I used to explain the temperature gradient by telling them, "If you stood on Mars, you'd wear sandals and a parka, since your feet would be as warm as a summer day but by the time you reached your head it'd be colder than winter in Antarctica!" which, although on the "tiny lies of oversimplification" side, is true-ish and a vivid enough image that they remembered months later.

We can migrat to Mars (1)

masongreenn (1804462) | more than 4 years ago | (#32094342)

It means in future we can migrate to Mars. http://cleancolonpro.net/ [cleancolonpro.net]

Guullly, Sarge! (1)

The Bad Astronomer (563217) | more than 4 years ago | (#32099020)

The paper in this article is pretty interesting, but I don't think it explains the newest features seen in these gullies; the way they terminate in the sand looks more like a liquid flow than solid [discovermagazine.com] . I suspect that the authors can explain many gullies on Mars, but not all the gullies. There may be more than one mechanism at work here!

Original article challenged by one commenter... (1)

Colin Douglas Howell (670559) | more than 4 years ago | (#32102716)

This comment [technologyreview.com] on the article at Technology Review challenges the conclusions reached. Quoted below; I've added in square brackets a couple of little elaborations of terms.

We've Been Down This Road Before
This model suffers from the same problem as the dry gully hypothesis put forth by Shinbrot et al. (2004) (http://www.pnas.org/content/101/23/8542.abstract [pnas.org] ). Yes, you can get an alcove and an apron, but it's missing the key defining characteristic of gullies, which is the channel. Their experiments did not produce the sinuous, anastomosing [wikipedia.org] [branching and reconnecting] channels often observed in martian crater wall gullies. They call some features in their experiments "channels," but terrestrial geologists studying landslides on sand dune faces wouldn't call those features channels. They're more like chutes [a term from avalanche geology]. The gullies on Mars also aren't just simple landslides of loose sand/dust on slopes; in many places the channels cut into the underlying rock, which requires something able to erode such rock (i.e. liquid water).

Sand is a fluid (1)

Civaus (1097087) | more than 4 years ago | (#32102748)

Sand is a fluid ..... so a fluid still flows on Mars ....
Check for New Comments
Slashdot Login

Need an Account?

Forgot your password?
or Connect with...

Don't worry, we never post anything without your permission.

Submission Text Formatting Tips

We support a small subset of HTML, namely these tags:

  • b
  • i
  • p
  • br
  • a
  • ol
  • ul
  • li
  • dl
  • dt
  • dd
  • em
  • strong
  • tt
  • blockquote
  • div
  • quote
  • ecode

"ecode" can be used for code snippets, for example:

<ecode>    while(1) { do_something(); } </ecode>