1. Earthshine

    When the crescent moon is just a sliver each month, the phrase—‘old moon in the young moon’s arms’— poetically describes a marvel of nature. This marvel shows the shadow of the Earth reflecting back the largely blue light from the Earth, known as earthshine. As recently presented at the 199th national meeting of the American Astronomical Society in Washington, D.C., astronomers from the University of Arizona Steward Observatory and the Harvard-Smithsonian Center for Astrophysics have benchmarked earthshine. Their findings provide clues as to how best to recognize distant planets that may harbor elements needed for life.

    Those elements—mainly, water ...

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  1. Digital Zookeepers Take a Census

    By Astrobiology News staff writer

    If the name of each species on Earth were put on a single recipe card, the box containing them all would stretch for over 6 miles. There are approximately 1.4 million species that have been named by researchers, but the true number of species on earth may be anywhere between 5 and 30 million species.

    If just keeping those animal names straight wasn’t challenging enough, the shuffling of cards over time has captured the combined interest of a 25 member scientific team, first organized by Dr. Charles Marshall (now at Harvard). In reporting some ...

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  1. Living in the Dark

    Over the past several years, scientists have discovered life in the most unusual places. From rocky abodes deep underground, to hot volcanic vents under the seas, there seems to be no place on Earth that life doesn’t exist.

    All of this life, even the life that lives in total darkness, is dependent on the Sun for energy. Plants and many Bacteria get their energy directly from sunlight, through photosynthesis. Animals and other organisms get their energy indirectly, by feeding on the complex organic molecules of photosynthetic organisms. These sun-produced organics eventually filter down into the Earth’s darkest reaches ...

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  1. The Tagish Lake Meteorite:

    Around 9:48 on the morning of January 18, 2000, a 150-ton space rock plunged into the earth’s atmosphere. As it approached the Canadian remote territories, the meteor traveled at the speed of a fast highway car (67 miles per hour). A scientific consortium of 4 universities and NASA is now trying to uncover the debris and sample the early solar system’s unique chemistry.

    Indeed, landing between the Yukon Territory and British Columbia in a remote vacation village, the rock volume started its descent totaling about the size of a small truck. At 5 meters (or 15 feet) across, the ...

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  1. NASA Scientist Finds Some Meteorites Not Sugar-Free

    A discovery by a NASA scientist of sugar and several related organic compounds in two carbonaceous meteorites provides the first evidence that another fundamental building block of life on Earth may have come from outer space. A carbonaceous meteorite contains carbon as one of its important constituents.

    Previously, researchers had found in meteorites other organic, carbon-based compounds that play major roles in life on Earth, such as amino acids and carboxylic acids, but no sugars. The new research is reported in a paper, “Carbonaceous Meteorites as a Source of Sugar-related Organic Compounds for the Early Earth,” by Dr. George ...

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  1. Bugs From Hell

    Deep, very deep, beneath the surface of Earth a microbial community dines and thrives. Slowly, but tenaciously, these deep dwellers feed on gases seeping into rock fissures and divide – maybe once every thousand years – to make more of themselves. Geochemists and microbiologists are delving into the details of extreme biochemistry deep within the Earth, where chemical and metabolic processes go at glacial pace, and life appears to be completely disconnected from the photosynthesis-based biological cycles that dominate surface life.

    “There is a huge biomass inside the Earth,” says David Boone, a microbiologist at Portland State University in ...

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  1. In Search of E.T.'s Breath

    If “E.T.” is out there, whether in the form of intelligent beings or much simpler organisms, we may soon be hot on its trail. For the first time in history, the dream of searching for signs of life in other solar systems belongs not only on the philosopher’s wish list, but on the list of doable and planned human endeavors.

    Momentum is gaining rapidly. Only 6 years ago, the first planet around another Sun-like star was discovered by scientists using Doppler Detection — a method that reveals Saturn-sized (or larger) planets close to their parent suns. Today, we ...

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  1. Living on Fool’s Gold

    A bright red river meanders through the countryside of southwestern Spain, its water acidic enough to eat through metal. Such an image brings to mind the worst excesses of industrial pollution, and scientists long assumed that a local copper mine had contaminated the Tinto River.

    Mining activity at the Tinto River dates back at least 5,000 years, and while it has altered the river it is not solely responsible for the river’s conditions. Acid rock drainage is a natural process that occurs when water, oxygen, and bacteria interact with sulfide minerals, producing highly acidic solutions. The Tinto River ...

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  1. Life Without Volcanic Heat

    An 18-story undersea vent off the Atlantic, near what has been called the ‘Lost City’, has recently revealed itself as ripe with exotic microbial life. From the University of Washington oceanography team, led by Deborah Kelley, recent reports in Nature magazine point to a new way to build such towering vents from what is nearly 100% limestone.

    Previous deep-sea finds of hot vents have not reached beyond 8-stories (80 feet) and also proved rich in a mix of black minerals (mainly iron-sulfides). But the new vent found atop the seafloor mountain Atlantis Massif, is nearly 10 stories taller. Not piled ...

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  1. Evidence of Bacteria on Europa?

    Jupiter’s moon Europa is thought to be one of the most likely abodes for microscopic life in our solar system. The ice-covered world may have liquid water, energy, and organic compounds – all three of the ingredients necessary for life to survive.

    Streaks of reddish-brown color highlight cracks in Europa’s outer layer of ice. Some scientists have speculated that microorganisms suspended in Europa’s ice may be the cause of these colorations. To test this theory, planetary geologist Brad Dalton of the NASA Ames Research Center compared the infrared (IR) signature of Europa’s ice with the IR signature of microorganisms living ...

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  1. Jurassic Spark: Early Ancestor of Mammals Found

    Based on an American Association for the Advancement of Science press release

    What is nearly 200 million years old, furry, weighed less than a paper clip and scurried beneath the feet of dinosaurs? A team of fossil-finders, led by researchers at Pittsburgh’s Carnegie Museum of Natural History, suggest the answer may include one of your relatives – a distant cousin of modern mammals.

    Classified as a new species, the newly discovered miniature mammal is the closest known relative to living mammals. It displays crucial mammalian features – a large brain and detached ear bones – yet it is forty million ...

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  1. The Oldest Life on Land

    Until recently, scientists believed that life on Earth did not emerge onto land until 1.2 billion years ago. In October 1999, Dr. Hiroshi Ohmoto of the NASA Astrobiology Institute pushed back that date a billion years by discovering 2.3 billion-year-old rock formations called laterites. Now, the discovery of 2.6 billion-year-old fossilized microbial mats intermixed with soil has pushed back that date even further.

    A team of scientists discovered the fossils in core samples taken from a mine in South Africa, which contained a layer of iron-rich soil combined with fossilized microorganisms. This mat-like layer was sandwiched between ...

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  1. One-Handed Life

    (Based on a press release from The Scripps Research Institute)

    Scientists at The Skaggs Institute for Chemical Biology, a part of The Scripps Research Institute (TSRI) in Southern California, published a paper in the February 15, 2001, issue of Nature that suggests a possible answer to how one of the early steps necessary for the origins of life arose.

    Principal Investigator M. Reza Ghadiri, Ph.D., Professor of Chemistry at TSRI and a member of the NASA Astrobiology Institute, has created a biological polymer that can discriminate between two types of building blocks, taking those that are similar and building ...

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  1. Earth's Oldest Mineral Grains Suggest an Early Start for Life

    Scientists are drawing a portrait of how Earth looked soon after it formed 4.56 billion years ago, based on clues within the oldest mineral grains ever found.

    Tiny zircons (zirconium silicate crystals) deposited in ancient stream deposits appear to indicate that Earth developed continents and water — perhaps even oceans and environments in which microbial life could emerge — 4.3 billion to 4.4 billion years ago.

    The findings by two research groups, one in Australia and the other in the US, indicate “liquid water stabilizes early on Earth-type planets,” said geologist Stephen Mojzsis, a member of ...

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  1. The Heat Is On: Asteroid Belt Found Around Nearby Star

    When unusually warm dust was first discovered (1991) around a nearby star, called zeta Leporis, infrared astronomers begun hunting in detail for the heat source. According to the latest research at UCLA, what the star may be undergoing is asteroid and planet formation similar to that of our own early solar system. For infrared astronomers the warm particle halo may reveal more than just a hot cloud. It may reveal a dusty disk that resembles an asteroid belt.

    Michael Jura and Catherine Chen reported their most recent findings at the annual meeting of the American Astronomical Society.

    “We chose to ...

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