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Water and life
Eth Mixer
Lightning is a dramatic display of electrical power, but it is also sporadic and unpredictable. Even on a volatile Earth billions of years ago, lightning may have been too infrequent to produce amino acids in quantities sufficient for life@a fact that has cast doubt on such theories in the past, Zare said.
Water spray, however, would have been more common than lightning. A more likely scenario is that mist-generated microlightning constantly zapped amino acids into existence from pools and puddles, where the molecules could accumulate and form more complex molecules, eventually leading to the evolution of life.
gMicrodischarges between obviously charged water microdroplets make all the organic molecules observed previously in the Miller-Urey experiment,h Zare said. gWe propose that this is a new mechanism for the prebiotic synthesis of molecules that constitute the building blocks of life.h
However, even with the new findings about microlightning, questions remain about lifefs origins, he added. While some scientists support the notion of electrically charged beginnings for lifefs earliest building blocks, an alternative abiogenesis hypothesis proposes that Earthfs first amino acids were cooked up around hydrothermal vents on the seafloor, produced by a combination of seawater, hydrogen-rich fluids and extreme pressure.
Yet another hypothesis suggests that organic molecules didnft originate on Earth at all. Rather, they formed in space and were carried here by comets or fragments of asteroids, a process known as panspermia.
gWe still donft know the answer to this question,h Zare said. gBut I think wefre closer to understanding something more about what could have happened.h
Though the details of lifefs origins on Earth may never be fully explained, gthis study provides another avenue for the formation of molecules crucial to the origin of life,h Williams said. gWater is a ubiquitous aspect of our world, giving rise to the moniker eBlue Marblef to describe the Earth from space. Perhaps the falling of water, the most crucial element that sustains us, also played a greater role in the origin of life on Earth than we previously recognized.h
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- 25/4/29() 18:09 -
