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Washington, Oct 06: A meteorite, which crashed into Australia 40 years ago, is telling researchers new things about how life may have started on Earth, and how that almost universal protein left-handedness came to be. For more than 150 years, scientists have known that the most basic building blocks of life - chains of amino acid molecules and the proteins they form - almost always have the unusual characteristic of being overwhelmingly “left-handed.” The molecules, of course, have no hands, but they are almost all asymmetrical in a way that parallels left-handedness. This observation, first made in the 1800s by...

Row erupts over 'life-starter' vents By Paul Rincon BBC science The earliest seafloor hydrothermal vents - supposedly more than three billion years old - may be nothing more than deposits from underground springs active in the last few thousand years. The 'ancient' rocks are exposed on land in South Africa That is the claim of two US geologists who carried out a new analysis of rocks from South Africa which were previously dated to the Archaean period - when life first began to diversify. The findings could have important implications for our understanding of the early Earth and the...

Man owes a lot to chunks of rock and ice floating through space. From ancient jewellery to water and possibly even the beginnings of life itself, scientists are discovering that comets have contributed in many ways to the development of life on the planet, Robert Matthews writes Since their discovery in an Egyptian cemetery more than a century ago, a handful of metal beads have perplexed archaeologists. As jewellery, the beads seem decidedly downmarket, being made of nothing more glamorous than iron. Yet clearly their owner, dead for more than 5,000 years, held them in great esteem - as do...

Full title: Ancient bubbles in Australian rocks show early Earth's air weighed less than half today's atmosphere Air bubbles trapped in 2.7 billion-year-old Australian rock suggest the Earth's atmosphere weighed less than half of today and was much thinner than previously thought. Researchers analysed the size of air bubbles that formed at the top and bottom of lava flows along the Beasley River in Western Australia's Pilbara region almost three billion years ago and used the data to calculate the atmospheric pressure at the time. The results suggest that the air at the time exerted at most half the pressure...

Abiogenesis: The First Frontier There are a number of models and theories out there about how life might have arisen and originated. The goal of this article is educate the reader as to the facts and the myths associated with abiogenesis. The best place to start off on abiogenesis would be the definition. Abiogenesis is the unguided arisal of life from non-living matter. Abiogenesis is basically an attempt to explain the origin of life while nullifying the possibility of a creator. Conditions of the old Earth: There are a number of theories on what the conditions of the prebiotic (pre-life)...

Clandestine comets found in main asteroid belt 19:00 23 March 2006 NewScientist.com news service Kimm Groshong You do not have to look to the outer edges of the solar system, or even out beyond Neptune to observe a reservoir of comets. A bevy of the ice-containing bodies lies disguised as main-belt asteroids between Mars and Jupiter, claim astronomers from the University of Hawaii, US. David Jewitt and Henry Hsieh have dubbed the new population "main belt comets". They describe three objects with near circular, flat orbits in the asteroid belt that stream volatile materials, producing an observable tail for weeks...

A new University of Colorado at Boulder study indicates Earth in its infancy probably had substantial quantities of hydrogen in its atmosphere, a surprising finding that may alter the way many scientists think about how life began on the planet. Published in the April 7 issue of Science Express, the online edition of Science Magazine, the study concludes traditional models estimating hydrogen escape from Earth's atmosphere several billions of years ago are flawed. The new study indicates up to 40 percent of the early atmosphere was hydrogen, implying a more favorable climate for the production of pre-biotic organic compounds like...

A classic experiment exploring the origin of life has, more than a half-century later, yielded new results. The original samples used by Stanley Miller to study the origins of life. In 1953, Stanley L. Miller, then a graduate student of Harold C. Urey at the University of Chicago, put ammonia, methane and hydrogen — the gases believed to be in early Earth’s atmosphere — along with water in a sealed flask and applied electrical sparks to simulate the effects of lightning. A week later, amino acids, the building blocks of proteins, were generated out of the simple molecules. Enshrined in...

The ancient sea floor was discovered in southwest Greenland A sliver of four-billion-year-old sea floor has offered a glimpse into the inner workings of an adolescent Earth.The baked and twisted rocks, now part of Greenland, show the earliest evidence of plate tectonics, colossal movements of the planet's outer shell. Until now, researchers were unable to say when the process, which explains how oceans and continents form, began. The unique find, described in the journal Science, shows the movements started soon after the planet formed. "Since the plate tectonic paradigm is the framework in which we interpret all modern-day geology,...

This single frame Rosetta navigation camera image of Comet 67P/Churyumov-Gerasimenko was taken on 7 July 2015 from a distance of 154 km from the comet centre. The image has a resolution of 13.1 m/pixel and measures 13.4 km across. Credit: ESA/Rosetta/NAVCAM --------------------------------------------------------------------------------------------------------------------------------------------- Stunned scientists announced Wednesday the unexpected discovery of large quantities of oxygen on a comet which streaked past the Sun in August with a European spacecraft in tow. The find came as a "big surprise", and challenges mainstream theories on the formation of our Solar System, said scientist Andre Bieler of the University of Michigan. Measurements suggested that...

The question about the origin of oceans on Earth is one of the most important questions with respect to the formation of our planet and the origin of life. The most popular theory is that water was brought by impacts of comets and asteroids. Data from the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) instrument aboard the European Space Agency’s Rosetta spacecraft indicate that terrestrial water did not come from comets like 67P/Churyumov-Gerasimenko. The findings were published today in the journal Science. Researchers agree that water must have been delivered to Earth by small bodies at a later...

Evidence is mounting that the time-weathered red planet was once a warm and water-rich world. And a Mars awash with water gives rise to that globe possibly being fit for habitation in its past – and perhaps a distant dwelling for life today. As sensor-laden orbiters circle the planet, NASA’s twin Mars rovers -- Spirit and Opportunity -- have been tooling about and carrying out exhaustive ground studies for nearly a year. The Opportunity robot at Meridiani Planum, for instance, has found telltale signs that water came and went repeatedly within that stretch of Martian real estate. While that intermittent...

Scientists have long assumed that life originated in the sea. If life did spring from salt water, that could explain why all organisms use salt. But Paul Knauth, an astrobiologist with Arizona State University, says while we always assume that life came from the ocean, this theory has never been proven. He suggests we need to consider the possibility that life originated in fresh water.The next time you reach for that bag of salty chips, think for a moment about salt and life. Humans need a certain amount of salt; it is necessary for the delivery of nutrients, the transmission...

A picture of the gun used in the experiments. The big white box at the left end of the gun is where the target is stored. Credit: Impact Laboratory, University of Kent Bullets of ice shot at high speeds can deposit organic compounds on surfaces they strike. New findings suggest that comets might, indeed, have helped deliver key ingredients of life to Earth and perhaps elsewhere, researchers say. The scientists detailed their findings in the June 13 issue of the journal Astrobiology.Craters on the moon are evidence that the Inner Solar System was prone to giant impacts from asteroids...

Given the reality of the dark spots, which soon became known as "atmospheric holes" because of their appearance in the images, there is only one explanation which has endured over all these years to present. That is, the holes are due to the shadowing of the atmospheric light by an object above the atmosphere. This object simply cannot be a stony or iron meteor because the holes are very large, tens of miles in diameter. A rock of this size would provide a disastrous impact on the Earth's surface. As it turns out, water vapor is very good at absorbing...

Early Earth Likely Had Continents, Was Habitable, According To New StudyA surprising new study by an international team of researchers has concluded Earth's continents most likely were in place soon after the planet was formed, overturning a long-held theory that the early planet was either moon-like or dominated by oceans. Artist's conception of the early magma ocean. (Image courtesy of NASA) The team came to the conclusion following an analysis of a rare metal element known as hafnium in ancient minerals from the Jack Hills in Western Australia, thought to be among the oldest rocks on Earth. Hafnium is found...

Source: University of Chicago Date: February 5, 2007 Ancient Rocks Show How Young Earth Avoided Becoming Giant Snowball Science Daily — A greenhouse gas that has become the bane of modern society may have saved Earth from completely freezing over early in the planet's history, according to the first detailed laboratory analysis of the world's oldest sedimentary rocks. A rock from a banded iron formation in northern Quebec, Canada. The bands vary in thickness from approximately 10 microns (less than the width of a human hair), to 10 meters (30 feet). This sample is measures a few inches across. At...

The world's oldest water, which is locked deep within the Earth's crust, is present at a far greater volume than was thought, scientists report. The liquid, some of which is billions of years old, is found many kilometres beneath the ground. Researchers estimate there is about 11m cubic kilometres (2.5m cu miles) of it - more water than all the world's rivers, swamps and lakes put together. The study was presented at the American Geophysical Union Fall Meeting. It has also been published in the journal Nature. The team found that the water was reacting with the rock to release...

Using primitive meteorites called chondrites as their models, earth and planetary scientists at Washington University in St. Louis have performed outgassing calculations and shown that the early Earth's atmosphere was a reducing one, chock full of methane, ammonia, hydrogen and water vapor. In making this discovery Bruce Fegley, Ph.D., Washington University professor of earth and planetary sciences in Arts & Sciences, and Laura Schaefer, laboratory assistant, reinvigorate one of the most famous and controversial theories on the origins of life, the 1953 Miller-Urey experiment, which yielded organic compounds necessary to evolve organisms. Chondrites are relatively unaltered samples of material from...

Most scientists have long assumed that life on Earth is a homegrown phenomenon. According to the conventional hypothesis, the earliest living cells emerged as a result of chemical evolution on our planet billions of years ago in a process called abiogenesis. The alternative possibility--that living cells or their precursors arrived from space--strikes many people as science fiction. Developments over the past decade, however, have given new credibility to the idea that Earth's biosphere could have arisen from an extraterrestrial seed. Planetary scientists have learned that early in its history our solar system could have included many worlds with liquid water,...