Science
Related: About this forumTraces of water in moon came from Earth, study finds
Traces of water inside the moon were inherited from ancient Earth, according to a fresh analysis of lunar rocks brought home by US astronauts.
The findings make for a clearer picture of our cosmic neighbour, once viewed as an arid expanse, but now considered a frost-coated rock that holds water throughout.
The latest results come from studies on the most extraordinary samples hauled back from the moon, including green-tinged stone collected by Apollo 15 in 1971, and orange material gathered by Apollo 17 in 1972.
The surprise discovery of the green rock, by Commander Dave Scott and lunar module pilot Jim Irwin, sparked a lengthy debate among the astronauts about the boulder's true colour while Nasa controllers listened in.
full: http://www.guardian.co.uk/science/2013/may/09/traces-water-moon-earth-study
sofa king
(10,857 posts)That virtually guarantees that some small fraction of Earth's water was spread throughout most of the rest of the solar system, because the ejected particles would only need about ten percent more velocity to reach Saturn--less if the ejected pieces pick up gravity assists from the Moon, Earth, and other planets (take as an example Cassini's roundabout path to Saturn).
So it's not crazy to guess now that some of that ejected water made it to Mars, Ceres, Europa, Callisto, Enceladus, Titan, and pretty much anywhere else inside of Uranus where we think life might exist.
We may someday soon be slightly disappointed to discover that there is life elsewhere in the Solar System... and it's blue-green algae, much like here on Earth because that's where it originated.
We may soon also see a goalpost shift as the search for life elsewhere in the solar system turns into a search for life that developed independently from Earth, or from whatever original source sparked life on Earth.
Victor_c3
(3,557 posts)It would show just how robust and far-spread life is and can be. I think that if we found the scenario that you mentioned to be the case that our chances of finding life in other solar systems would be much more likely.
To a guy who only casually follows our discoveries in space, Enceladus seems like the most likely spot in my mind for finding life. I hope to see a mission to seriously explore that moon in the next decade or two.
muriel_volestrangler
(101,295 posts)(or, just possibly, when it had formed once, and was then wiped out by the enormous collision that formed the Moon from a significant part of the mantle of the Earth - but that's pure speculation that life could have formed earlier and then get wiped out, on my part; the point is that the ancestor of all life on earth formed after the collision).
This is water that was trapped inside the volcanic glass when the collision happened. Or, as Jim__'s link below suggests, came from carbonaceous chondrite meteorites after the Moon was formed. But they're not saying it came from an Earth with life.
sofa king
(10,857 posts)The water discovered on the Moon may be primarily from the "creation event," but the math has already been done to show that Earth's first astronauts certainly predated humans by millions of years.
http://arxiv.org/abs/1204.1719
http://www.technologyreview.com/view/425093/earth-ejecta-could-have-seeded-life-on-europa/
According to that second paper, some earth impact material escapes the solar system entirely, which was something of a surprise at the time.
And, this is nothing about nothing, but there is an outside chance that the first human-made object to escape the solar system entirely was a steel plate that was, uh, "projected" from the underground Pascal-B nuclear test via a mine shaft about five weeks before Sputnik launched in 1957. The plate was estimated to be doing six times earth escape velocity at ground level, which suggests that if it did not burn up while exiting the Earth's atmosphere, Elvis would have left the building. (The scientist in charge of the experiment does not think the plate made it to space before burning up.)
http://en.wikipedia.org/wiki/Operation_Plumbbob
Jim__
(14,074 posts)This article at phys.org mentions that possibility:
By showing that water on the moon and Earth came from the same source, this new study offers yet more evidence that the moon's water has been there all along, or nearly so.
"The simplest explanation for what we found is that there was water on the proto-Earth at the time of the giant impact," said Alberto Saal, a geochemist at Brown University and the study's lead author. "Some of that water survived the impact, and that's what we see in the moon."
Or, the proto-moon and proto-Earth were showered by the same family of carbonaceous chondrites soon after they separated, said James Van Orman, professor of earth, environmental and planetary sciences at Case Western Reserve, and a co-author.
...
The finding is not necessarily inconsistent with the idea that the moon was formed by a giant impact with the early Earth, but presents a problem. If the moon is made from material that came from the Earth, it makes sense that the water in both would share a common source, Saal said. However, there's still the question of how that water was able to survive such a violent collision.
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