• <noscript id="q0sqs"><kbd id="q0sqs"></kbd></noscript><table id="q0sqs"><option id="q0sqs"></option></table>
  • <td id="q0sqs"></td>
    <td id="q0sqs"><kbd id="q0sqs"></kbd></td>




    2015-1-27 10:20










    Unlike every other planet in our solar system, Earth's surface is 70% liquid water, which while useful for life, is also kind of weird, because everything we know about how and when our planet formed says Earth's surface should be bone dry.

    The story goes like this: our solar system formed from the collapse of large cloud of dust and gas. The dense blob of gas at the center ignited to form the sun, which as a young, unstable star unleashed a fierce solar wind. Over time this stream of charged particles pushed the remaining gas cloud farther and farther out, leaving only solid particles behind to clump together into rocks, planetesimals, and finally, the rocky planets of the inner solar system that we know today.

    And here's the problem :water, in the from of ice, couldn't have been one of the solid particles that stuck around before our planet, because the early inner solar system was far too hot for frozen water, and any water vapor would have been blasted away by the solar wind.

    So if Earth didn't start off with water, how did we end up with such splendid oceans? We know H20 wasn't manufactured here over the eons, because natural processes like combustion, breathing and photosynthesis create and destroy roughly equal amounts of water. And either way, the amounts in question are so miniscule that they can't account for the abundance of water on the planet.

    Since Earth's water was neither part of the original package nor manufactured here. It must have flown in from far away, on meteoroids or comets or other bodies originating in the outer solar system, where they were far enough from the Sun for frozen water to survive. The dirty ice balls that we call comets are a logical candidate for the source of our water. But were ruled out when we discovered that they are far richer in heavy hydrogen than Earth water. Heavy hydrogen has a neutron as well as a proton in is nucleus, and for every million hydrogen atoms in Earth water, about 150 are heavy ones, while typical comet water has twice that many.
    由于地球的水并非起源于此或产生于此,它肯定是从远方流入的,从陨石或彗星、或者他外太阳系天体来。在那里,它离太阳够远,能让水保持冻结。那些脏冰球,即“彗星“ 是水的来源的合适候选者之一。但已被淘汰,当我们发现,其重氢含量比地球上的水高得多。重氢的原子核中有一个中子和一个质子,地球水中,每一百万个氢原子中就有150个是重氢,而一般彗星水是它的两倍。

    These mismatched chemical signatures suggest that Earth's water could not have arrived on comets. It turns out that the most likely source for Earth's water is a type of meteorite called a carbonaceous chondrite." Chondrite" is just the name given to the class of stony meteoroids that most commonly strike the Earth. But only the carbonaceous chondrites contain water as well as lots of carbon, if you couldn't tell from their name.
    这些不相符的化学标志表明,地球的水不可能来自于彗星。结果证明 地球水最可能的来源是一种被称为碳质球粒陨石的陨石。“球粒状陨石“只是那些常袭击地球的岩类流星体的名字。但只有碳质球粒陨石中含有水以及大量的碳,如果你没从名字里发现的话。

    They have water in then because they formed out beyond the sun's "frost line", and what's more, their water has levels of heavy hydrogen similar to that of earth water, strongly suggesting that these earth-crashers are the source of our ice caps, clouds, rivers and oceans.
    它们含水,因为它们形成于太阳的“冰冻线“外,另外,其水中的重氢含量和地球水相似,强有力的证明了,这些地球的不速之客是我们冰盖、云层、 河流和海洋的来源。

    And thus the water that turned our planet into a blue marble came, quite literally, out of the blue.

    金沙贵宾会sands <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <文本链> <文本链> <文本链> <文本链> <文本链> <文本链> <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <蜘蛛词>| <文本链> <文本链> <文本链> <文本链> <文本链> <文本链>