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Mars Images Reveal Evidence of Ancient Lakes
Matt_dk writes "Spectacular satellite images suggest that Mars was warm enough to sustain lakes three billion years ago, a period that was previously thought to be too cold and arid to sustain water on the surface, according to research published today in the journal Geology. Earlier research had suggested that Mars had a warm and wet early history but that between 4 billion and 3.8 billion years ago, before the Hesperian Epoch, the planet lost most of its atmosphere and became cold and dry. In the new study, the researchers analysed detailed images from NASA’s Mars Reconnaissance Orbiter, which is currently circling the red planet, and concluded that there were later episodes where Mars experienced warm and wet periods."
Until we go there and see. Interesting idea though.
"If you want to know what happens to you when you die, go look at some dead stuff."
Your ex is over 3 billion years old? That must have chafed..
which is totally what she said
Europa may well be warm and wet under the layer of ice. In fact Europa probably is, and might in fact harbor life. Can we please forget about Mars? Mars sucks because we keep going there and not really finding anything of importance. I am tired of Mars, there are other, more interesting places to explore.
Wow, you seem terribly defensive over what is a pretty reasonable question. This is slashdot, you are allowed to ask things here...
Anyways, from what I understand (and this is in no way my field), they usually date these sorts of things by observing what kind of geological features are on top. If a crater has numerous smaller craters in it, then you know the larger crater is older. With the crater distribution they can make pretty reasonable estimates about the age of something. Similar methods techniques could use other forms of erosion.
Dating like this obviously isn't exact, and you'd have to ask a geologist for more details on the accuracy and techniques. For that matter, I haven't read TFA so I don't know that this is exactly how it was done. If you are really curious, I suggest you RTFA, and read any papers these scientists have/will release on their findings.
"linux is just DOS with a UNIX like syntax" -- Galactic Dominator (944134)
The researchers determined the age of the lakes by counting crater impacts, a method originally developed by NASA scientists to determine the age of geological features on the moon. More craters around a geological feature indicate that an area is older than a region with fewer meteorite impacts. In the study, the scientists counted more than 35,000 crater impacts in the region around the lakes, and determined that the lakes formed approximately three billion years ago. The scientists are unsure how long the warm and wet periods lasted during the Hesperian epoch or how long the lakes sustained liquid water in them.
So to answer your question the moon is the reference point.
It has large error bars, but it's the best we have until we can send radiometric dating to these areas. [Crater Counting]
Contrary to what the "internet" likes to tell you, many people question what scientists say because they want to see actual proof to support the claims rather than just additional layers of theories and educated "guesses".
And the people who are legitimately intellectually curious rather than simply delighting in taking jabs at the "scientific orthodoxy" don't universally phrase their questions as "Do you know what you're talking about or are you making shit up that supports your preconceived notions?"
"How do they determine those dates?" is a fine question, one I am curious about as well. "Gee, in the scientific method I'm used to, you have to have a known reference. Do they have one? Have they been following the scientific method?" kinda makes you sound like the kind of person you are implying you aren't. Maybe you're just being defensive, or using modding reverse-psychology. But really, just leave that part out.
The enemies of Democracy are
Continuing off topic...
Your post reminds me of the day a coworker came into my office with a look of deep thought on her face, asking why we need to use money. Not getting where she was going, I started explaining that money is just an accounting system. That didn't satisfy her, so I started to explain how it evolved from barter.
She stopped me, and saying that she understood that, followed by a but "Why can't we just go to work, and when we need something just go to the store and get it? Why do we need to keep track of it with money? That's what I think we should do."
At that point I got what she meant, and told her that theoretically we could. And said "What you are describing is communism." She then puffed up and angrily said "YOU are a communist." and stomped out.
How are these dates determined?
Basically, they're counting craters.
The idea is that everything in the solar system is being steadily bombarded by random bits of debris. More craters means that something has been exposed to the elements for a longer amount of time.
In this case... If you have a once-lakebed that's now covered with craters, it must have been a while since there was water in it.
No, it isn't perfect. But it isn't too horrible either.
And, of course, the numbers will be refined as more/better data and measurements become available.
"Work is the curse of the drinking classes." -Oscar Wilde
any effort to seed the martian atmosphere would at best be a temporary(ok, a few million years) improvement. Mars lacks the gravity to hold the atmosphere. what's more, the warmer the atmostphere the faster it will disipate off into space.
in the 3 billion years since the lakes existed, mars has reached an equilbrium.
Sorry to post off topic to your sig, but universal helthcare is socialist. whether or not it is a good thing remains to be seen.
NO. It's a social program, but it not socialist. Unless you consider the police, army, judicial system and public schools also to be socialist.
Socialism is very different than social programs.
Tesla was a genius. Edison however was a overrated hack who liked to torture puppies.
I'm probably going to get modded down or flamed for being a heretic for daring to question modern scientific orthodoxy
Ah, the classic cry of the rebel without a clue.
Listen up, kid: you are not an iconoclast. You are not boldly speaking truth to power. You are not Martin Luther nailing his theses to the cathedral door. You are not a special snowflake.
Everyone who has ever worked in this project has thought of, and answered, every single one of your questions long ago. And those answers are easily available with a small amount of digging, which you would do if you had any interest in the actual answers instead of just self-aggrandizing puffery.
The correlation between ignorance of statistics and using "correlation is not causation" as an argument is close to 1.
So, the aliens have successfully stolen all of the water from Mars (as reported in thousands of lousy science fiction movies and TV dramas). Is the Earth next on their list of planets to steal the water from? I mean, it's not like you could possibly manufacture your own water by taking a couple of common elements in the universe, like hydrogen and oxygen, and combine them using a stupid trick like fire.
Who would win this election: Andrew Weiner vs Andrew Weiner's weiner.
So if you were generating the same % of gas annually, would it not be in equilibrium?
Where was the last place you saw it? You must have lost it somewhere between here and there. Don't forget to check under the sofa cusions.
Who would win this election: Andrew Weiner vs Andrew Weiner's weiner.
What is so special about humans manipulating measuring equipment versus robots?
We do it better.
Nope, just another philosophy major on the Internet
Faster! Faster! Faster would be better!
As a Canadian, I have to quirk my eyebrow at that.
You realize that we have supplementary coverage up here, right? Hear me out.
The government provides basic health coverage. They cover almost everything, from emergency treatment to birth and annual physicals.
We don't get coverage for private rooms, eyeglasses, Rx medication (unless you spend $3k a year or more, long story), massage, physio, etc. There's a long laundry list of things that aren't covered. Ambulance rides aren't covered, but that's because too many people were using it as a taxi service. It's $65, but when you need one, it's money well spent.
I can go out and buy more coverage. My wife gets Green Shield from work, and that covers $250 in eyeglasses every 2 years, massage and physio, 80% reimbursment on medication, private rooms, dental care, etc. I have an HSA at work, but I use my wife's plan instead because it's a better plan.
When my kids were born, it cost me $12 for parking each time. When they got hit by a car and rushed to the hospital, it cost me $10 for dinner and $65 for the ambulance. (For each of the above, there were multiple ultrasounds, xrays, blood tests, beds, bandages, etc.) That's all I had to pay.
When it's critical, there aren't wait times, despite what you may have heard. My friend had a sharp pain in his head when he coughed -- he was ushered in right away, had an ultrasound, a CT scan, and a spinal tap within 30 minutes of arriving at the hospital. (The wait was because someone was in the machine.)
I was having chest pains about six months ago, so I went to a drop-in clinic (not my regular GP) and had an ECG within about 15 minutes.
This is all stuff that's just covered up here, and always has been. True, the system has faults, but that's because our politicians up here get really good secondary coverage so they don't feel any pain from cutting back on health care spending. (These are the same breed of jokers that brought Canada from the 3rd largest Navy in the world at the end of WW2 to the 3rd-div team it is today.) If they increased health-care funding, we'd be in much better shape and the Americans would have nothing to point their fingers at.
By the way, my tax rate was ~15% in 2008. I haven't done my 2009 taxes yet. (It's not a directly fair comparison because we also have subsidized education up here -- my engineering degree cost me ~$0 net.)
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ECHELON is a government program to find words like bomb, jihad, plutonium, assassinate, and anarchy.
Adding CO2 and water to Mars is going to involve industry. And energy. Shitloads of both. Industry is going to involve, by necessity, many of the chemicals you mention, either to run the machinery or as a byproduct of it. Therein lies the problem. Mankind isn't going to wait around for hundreds of years for a long, slow, low-energy terraforming system to work, so by the time we've turned the dial to 11 for enough years to have reached a semi-breathable atmosphere, it'll be polluted.
Now add in your comment about "maintaining our lifestyle". If you typed your post on a computer while wearing clothing in an enclosed space with heat, congratulations, that requires all the chemicals you mentioned above and more.
Even if the Earth's population stopped growing right now, we likely cannot maintain the lifestyle we enjoy now in the US and Europe, and there'd be no way in hell we can extend that same lifestyle to the rest of the planet. Add in the resources necessary to start terraforming Mars and the time it will take for it to complete, and we'll be loading Mars up with more people than it can sustain during the entire process. As soon as Mars has an atmosphere that can grow a few crops and support 50,000 people, we'll dump a half million there in the false hope it'll relieve the population pressures on Earth. And both planets will be overpopulated continuously until we figure out how to overpopulate another planet.
Robinson's "Mars" series, mentioned in the post you replied to, is an excellent read. Robinson has an interesting and thoughtful, if just a tad hopelessly optimistic at the end, view of how terraforming might play out. It's a relatively well-researched (or seemingly so) series, with a lot of interesting theories on approaches to terraforming, and plays out a very human approach to it.
"This post contains words, known to the State of California to cause thought. Wash brain thoroughly after reading."
The limitations of our current robots were based on space, cost, and durability. A geologist might be able to search the terrain faster, but they won't be able to be there for more than a few days or weeks at best, and each geologist could really only search one general area. In the same space as your single geologist and all the food and resources he/she will need, we could explore multiple places on the surface of Mars with a generous handful of Spirit-type robots, and they could all stay there for years collecting data.
The reason Spirit and Opportunity are so slow is because they operate on a small solar array, that generates (at peak) 140 watts for the 4 hours of daylight they get in a Martian day. That's about 560 watt/hours an m-day at best, and that's all the energy they need to do what they do. That's a lot of science packed into that amount of energy. They are currently getting a fraction of that due to dust on the arrays, and yet they are still collecting good science, six years in.
If you want enough energy to support a human being there, you're talking nuclear engines. If you're going to make that kind of energy available, you might as well power the robots with nukes - they will then be able to move faster than a human could, and there could be hordes of them for the same cost and resources expended sending one human. And they could stay for years.
To get a single human to mars, on the surface, and back to Earth, you'll need about a half ton of dehydrated food, enough water to recycle so they have a continuous supply, and probably a few thousand watt-hours a day minimum for the entire trip for heat, light, etc. You'll also need radiation shielding (likely tons of it) for the multi-year trip, room for them to exercise, many tons of fuel for the two-way trip, etc.
Spirit weighs about 400 pounds, or a little over twice the weight of a human. But you save the half-ton of food, the water, more than half the fuel (no return trip, no need to re-orbit it), and almost all the energy needed to sustain life during the voyage. The ship is simpler, since you need almost no shielding, no living space - just strap a few (or a few hundred) robots around the outside of a rocket engine.
Take a science team of a dozen, and you could probably have at least 50, maybe 100 robots take their place. And those robots would be able to work there for years. Each could have its own nuclear plant and probably have power and functioning instruments for decades (energy starvation from the solar cells is what is slowly killing off the current robots).
Plus, robots can make a one-way trip. No need to store fuel to bring them all back, just enough for a few dozen of them to send a sample back to a central ship in orbit, which can then pack up the samples and send them back on a relatively small rocket that weighs a few hundred pounds.
"This post contains words, known to the State of California to cause thought. Wash brain thoroughly after reading."