quarta-feira, 11 de setembro de 2013

Scientists find the building blocks of extraterrestrial life in California meteorite

In April 2012, a large meteorite streaked across the morning sky in California, with a sonic boom rattling houses up and down the San Joaquin Valley. Fragments of the exploding space rock came down around Sutter's Mill, California, the same place where prospectors discovered gold in California, sparking the 19th century gold rush.

Scientists working with samples of the meteorite subjected the rock to forensic examination looking for evidence of organic compounds. They're interested in learning just how common the basic building blocks for life are in the solar system. If those compounds are common, then life may have arisen on Earth quite easily. If rare, then it becomes harder to explain the mechanics of the origin of life.

It should be noted here that despite popular sentiment, neither result impacts the ultimate question of creation.

Biochemist Sandra Pizzarello from the Arizona State University in Tempe told Space.com, "Their composition therefore has always been seen as an indication that the precursors to the evolution that led to the origins of life could have come from the extraterrestrial material of meteorites."

In other words, the molecules that form life on Earth may have come from elsewhere.

One of the problems with the scientific theory of creation and evolution of life is that it is difficult to explain how life arose on a planet that should otherwise be sterile. The primordial Earth was incredibly hostile to life. The planet baked at hundreds of degrees at the surface destroying any possibility that life could naturally evolve. Liquid water did not exist at the surface, which was initially molten.

So how did we get life from a virtual Hell on Earth?

Over time, the planet's surface cooled and water, as well as important molecules arrived on the surface. Comets bombarded the cooling planet, delivering their dust and ice, rich in organic compounds, to the surface, forming the oceans and most of the water now on the planet.

Meteorites also brought organic compounds.

How those compounds developed to create life remains a mystery that scientists still have difficulty replicating in a lab. However, according to theory, those compounds eventually came together in just the right proportions to form life, which subsequently evolved into all that lives on the Earth --including us.

The meteorite from Sutter's Mill did not produce very promising results at first. Initial study suggested that organic compounds were virtually nonexistent. However, a subsequent study that included dissolving fragments of the meteorite in conditions similar to steaming hot hydrothermal vents on Earth, yielded a startling result. The meteorite was actually rich in compounds.

This suggests that under the right conditions, organic compounds embedded in the rock can emerge and create the soup of molecules needed to form life.

Of course, the soup of molecules extracted from the rock formed no such life nor was that the aim of the experiment. Moreover, no life has ever been created in the lab from non-living compounds. It appears there remains a missing ingredient.

Aside from that, the study tantalizingly suggests that compounds needed to create life are otherwise common and may be found throughout the solar system, and possibly the universe entire.

Source: catholic.org

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