Posted on 06/13/2010 8:05:02 PM PDT by NormsRevenge
PARIS (AFP) – A huge, potentially life-giving sea likely covered more than a third of Mars some 3.5 billion years ago, according to a study released Sunday.
Spread over an area the size of the Atlantic Ocean, it would have straddled the north pole and contained the equivalent of a tenth of the water on Earth.
For decades scientists have argued as to whether the Red Planet once harboured bodies of water big enough to help nourish a true hydrological cycle marked by evaporation and rainfall.
Recent evidence suggests as much, but doubts remained.
To dig deeper, Gaetano Di Achille and Brian Hynek of the University of Colorodo in Boulder sifted through huge stores of images collected by NASA's Mars Orbiter Laser Altimeter (MOLA) in the late 1990s and other more recent European and US satellite-based monitoring systems.
The data was not new, but the researchers were the first to link up all available information on Mars' terrain into a single computer-driven model.
The study, published in Nature Geoscience, found 52 river-delta deposits scattered across the planet.
More than half occurred at about the same elevation, and thus probably marked the boundary of the once-massive sea.
All of these would have been connected either directly to the ocean, or to its groundwater table along with several large, adjacent lakes.
The scientists calculated that the ancient sea covered 36 percent of the planet's surface and contained about 124 million cubic kilometres (30 million cubic miles) of water.
(Excerpt) Read more at news.yahoo.com ...
This May 2010 NASA image, combining data from two instruments aboard NASA's Mars Global Surveyor, depicts an orbital view of the north polar region of Mars. A huge, potentially life-giving sea likely covered more than a third of Mars some 3.5 billion years ago, according to a study released Sunday.… Read more » (AFP/NASA/File)
Obama sez: the disappearance of the Martian oceans is all Bush’s fault.
ping
Did global warming dry up the water? /s
A third of Mars once covered by ocean... before Bush!
Interesting
the lower third...
Any evidence that they had crappie, perch, or walleye?
90% of what is now France was once covered by manure; quite a lot of it stayed there.
I have three problems with this. First and most important is our own grotesque lack of planetary models upon which to formulate theories about why things look the way they look. We have been able to study the surface of one planet in detail, and our own geologic studies still have significant gaps. It is presumptious to announce that whatever happened here must also happen on Mars.
The second problem is noted in the article. Where did the water go?
The third problem is more important. Where did the water originate?
1: Mars is avery ordinary rocky planet, not that different from Earth. Water is still water on Mars, as are dirt, rock, gravity, heat, wind, etc. Mars is not a place where you can imagine a different physics, a different chemistry, or altogether different outcomes to similar physical processes.
2: Most Martian water evaporated into space over a long period of time. Obviously, some remains. The Martian gravity well is far shallower than Earth’s.
3: Martian water originated from the same place that terrestrial water originally came from: accretion of water ice bearing material and hydrated minerals in the solar accretion disc. This is the same place that everything now found on all the planets planets came from: rock, metal, gases, water, hydrocarbons, etc. Where do you think it came from? Do you know of any other source? If so, please share.
I wonder why those two rovers on the Mars surface didn’t find any organic evidence of life?
Your theory here is based on the idea that all surface formation happens the same on every planet. Cite some examples that have proven this.
2: Most Martian water evaporated into space over a long period of time. Obviously, some remains. The Martian gravity well is far shallower than Earth’s.
The scientists who study this can't figure out where it went, if it was there.
3: Martian water originated from the same place that terrestrial water originally came from: accretion of water ice bearing material and hydrated minerals in the solar accretion disc. This is the same place that everything now found on all the planets planets came from: rock, metal, gases, water, hydrocarbons, etc.
Well there ya go. Water came from water. How silly of me. One might have expected some complex sequence of reactions from elements formed after a supernova, but who needs any of that. It's just there.
Where do you think it came from? Do you know of any other source? If so, please share.
I don't know if it was ever there, and the evidence for the claim that an ocean covered a third of the Martian surface is remarkably weak. So what reactions led to the formation of the ice? How did it survive a weak gravity field during the formation of a planet, an event that must generate tremendous heat?
1. Occam’s razor.
2. Send those “scientists” back to school.
3. Duh. How far back do you want to go? The Big Bang? I thought we were discussing planetary origins, not cosmology. How could I be so off-base?
4. An event that must generate tremendous heat. For someone who claims ignorance of planetary processes, you all of a sudden seem to know something. This is quite remarkable.
But, FYI, most recent planetary formation scenarios postulate relatively cold processes. The ball of molten rock scenario has been pretty much debunked.
Thanks Jet Jaguar. When I get a chance (possibly tonight, otherwise sometime tomorrow) I’ll plaster in some info about this claim, which isn’t new.
Rocky planets are in fact the exception in this solar system. Half of our planets are gas giants. Mercury would be a moon if it orbited Jupiter or Saturn, and it would not be the biggest one in either case. Venus is a mystery, but it is considered a rocky planet as is the Earth. Mars is considered an embryo that did not merge with enough material to become an Earth sized planet. So much for your supposition that it is an "ordinary rocky planet."
But in which solar system? Our sun is one of 200 billion in a small galaxy, which is one of 170,000,000,000 in the observable universe. You've based your assumption on roughly 1/34,000,000,000,000,000,000,000 of the observable evidence. If you plucked twenty molecules out of a playing card, you would not use them to predict that you will be dealt a royal flush.
2. Send those “scientists” back to school.
The "scientists" were cited the source article.
3. Duh. How far back do you want to go? The Big Bang? I thought we were discussing planetary origins, not cosmology. How could I be so off-base?
Elements heavier than lithium form in super novas. A super nova forms the accretion disk that becomes a new sun and planets. Carbon, iron, magnesium, etc. were not formed in the big bang, they came much later. You are off base by several billion years.
4. An event that must generate tremendous heat. For someone who claims ignorance of planetary processes, you all of a sudden seem to know something. This is quite remarkable. But, FYI, most recent planetary formation scenarios postulate relatively cold processes. The ball of molten rock scenario has been pretty much debunked.
If I had said it formed from a ball of molten rock, you would have a point. But I didn't say that and you don't. Planetesmals form into planets through impact, accretion, and merger. All of these are kinetic processes between massive bodies and all of them produce heat, as does the increased gravitation caused by the increase in mass. Think of Tunguska. That was possibly a 100 meter object. The energy release was comparable to a 30 megaton H bomb. A planet is made up of tens of thousands of those.
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