Fascinating observations from Mars reported in this weeks edition of Science
AbstractWhat this means is that at some point in its history, Mars had flowing water with enough power to transport rocks and turn them into pebbles. Pebbles are formed as rocks rolling along in water knock against each other, wearing away any irregularities on their surface to make them smooth and rounded.
Observations by the Mars Science Laboratory Mast Camera (Mastcam) in Gale crater reveal isolated outcrops of cemented pebbles (2 to 40 millimeters in diameter) and sand grains with textures typical of fluvial sedimentary conglomerates. Rounded pebbles in the conglomerates indicate substantial fluvial abrasion. ChemCam emission spectra at one outcrop show a predominantly feldspathic composition, consistent with minimal aqueous alteration of sediments. Sediment was mobilized in ancient water flows that likely exceeded the threshold conditions (depth 0.03 to 0.9 meter, average velocity 0.20 to 0.75 meter per second) required to transport the pebbles. Climate conditions at the time sediment was transported must have differed substantially from the cold, hyper-arid modern environment to permit aqueous flows across several kilometers.
The pebbles on Mars have been there long enough to have become incorporated into concretions formed over time from the sand particles they were deposited in.
This has major implications for young-earth creationists who desperately cling to the biblical myth that Earth was created simultaneously with the rest of the Universe between six and ten thousand years ago and everything in the Universe was created exactly as we see it today.
One of their favourite claims is the Earth must have been specially and intelligently designed because it occupies the 'Goldilocks zone' around the Sun where water can exist in each of its three physical states - solid (ice), liquid (water) and gas (water vapour). Creationists claim that the probability of Earth occupying just this 'narrow' band around the Sun is vastly unlikely. This of course ignores the fact that life has evolved on Earth because Earth has the conditions for it to have evolved, and that it fits the conditions on Earth like a hand in a glove because that's what evolution by natural selection causes, as is explained by the Theory of Evolution.
Flowing water on Mars means these conditions existed there at some time too, so widening the 'Goldilocks zone' to include the orbit of Mars and so giving the lie to Creation pseudo-scientist calculations that the 'Goldilocks zone' is very narrow. In fact, the occurance of water in its three physical states on Earth are largely because of Earth's geology and meteorology - mass/gravity, atmosphere, atmospheric pressure, etc - just as when they existed on Mars it was due largely to Mars's geology and meteorology not Mars's distance from the Sun.
The existence of pebbles, which do not form over night, and, more importantly their inclusion in concretions of sand particles, formed with "minimal aqueous alteration" (i.e. after the water had either evaporated due to Mars's low gravity and thin atmosphere, or had become locked up in subterranean permafrost, speaks of a very old Mars, and certainly one more than a few thousand years old. This evidence for liquid water also raises the possibility of the Creationists' nightmare scenario of simple life having evolved on Mars. The search for that continues...
Creationists try to explain away deposits such as these on Earth as due to the Noachin Flood, sent by their god in a fit of temper, to kill all living things because of their 'wickedness'. Do they suppose a similar flood once killed all living things on Mars too, but their god didn't tell a Martian to build an Ark?
Or maybe the Flood reached up higher than the highest mountain on Earth and deluged the inner planets too, but avoiding the Moon which shows no such signs of flowing water.
I dare say one of their 'brilliant scientists' can explain it all...
Don't laugh. It isn't nice.
Martian Fluvial Conglomerates at Gale Crater
R. M. E. Williams, J. P. Grotzinger, W. E. Dietrich, S. Gupta, D. Y. Sumner, R. C. Wiens, N. Mangold, M. C. Malin, K. S. Edgett, S. Maurice, O. Forni, O. Gasnault, A. Ollila, H. E. Newsom, G. Dromart, M. C. Palucis, R. A. Yingst, R. B. Anderson, K. E. Herkenhoff, S. Le Mouélic, W. Goetz, M. B. Madsen, A. Koefoed, J. K. Jensen, J. C. Bridges, S. P. Schwenzer, K. W. Lewis, K. M. Stack, D. Rubin, L. C. Kah, J. F. Bell III, J. D. Farmer, R. Sullivan, T. Van Beek, D. L. Blaney, O. Pariser, R. G. Deen, and MSL Science Team
Science 31 May 2013: 340 (6136), 1068-1072. [DOI:10.1126/science.1237317]
Life's a Beach: Rover Finds Mars Pebbles; Ian O'Neill, 31-May-2013.
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