- an asteroid is a rock in space, and is larger than a meteoroid
- when an asteroid crashes into our atmosphere, it becomes a meteor
- when this rock survives on our surface, it is termed a meteorite
Friday, January 31, 2014
DID LIFE, WATER AND GOLD COME FROM OUTER SPACE?
In short, while the latest scientific evidence seems to say that the water in the ocean and gold in jewelry had origins in outer space, there are contradicting viewpoints. The space theorists say that our planet, and all other planets, upon formation, lacked, for example, water and key gases. Thus, for life to form, something must have come from somewhere out there.
Mind you, life as we know it did not need to have been created here. Perhaps some alien form almost four billion years ago planted the seeds of life on Planet Earth, but that leads to what was their origin. In any case, they would not have bothered to come here if there was no water. But, could life have naturally formed on Planet Earth and "other" aliens tens of millions ago left a life form with some intelligence? Probably not because bacteria and Homo sapiens share the same type of DNA. Unless, life and DNA are universal.
Nevertheless, it comes back to asteroids and, perhaps too, comets, bringing some of the important building blocks of life to some barren planet in the Universe to have started this all. Without getting into the deep chemistry, the latest findings seem to suggest that the type (isotope ratio of hydrogen, deuterium and/or tritium) of hydrogen found here is similar to that of asteroids. This isotopic ratio also seems to say that the volatiles on Earth favor asteroids over comets as the source. The hydrogen thus came as ice (water is hydrogen and oxygen) from asteroids. Comets originate deeper in space and are dusty ice balls, with gases like methane and carbon dioxide.
Then today, a major study was reported saying that space dust also brings water, plus organic compounds. Space dust is microscopic. While ice from asteroids are more likely why we have oceans, interplanetary dust, because of the organics, could well have been necessary for the creation of life.
Mind you, all the above remain theories. There are other studies showing that there was sufficient water in the formation of Planet Earth. The edge today, however, goes to the space theorists.
About gold, the story is similar. If gold formed when our planet came together, it should have all sunk below the mantle because it is so dense. Thus, as one theory goes, meteorites must have fallen bringing gold, and sites like South African got most of the good stuff. So what is the difference between an asteroid and a meteor?
In other words, the only difference is that an asteroid is larger than a meteoroid, but becomes a meteor, then a meteorite, just like a meteoroid.
While gold from space seems to be favored, there is some support to the concept that, perhaps, the gold was here all the time, and while it did sink, some remained in the magma, and volcanic activity or plate tectonics brought some to the surface. The gold itself generally can be traced to hot salty water that dissolves the gold and deposits it in rock fractures.
Just as we haven't yet seen 96% of matter (Dark Matter), the questions of exactly where water or gold came from and the origin of life, remain mysteries today. There are theories, but facts are elusive. Someday, perhaps.