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  1. Do We Know What Killed the Dinosaurs?


    What killed the dinosaurs? Their sudden disappearance 65 million years ago, along with at least 50 percent of all species then living on Earth, is known as the K-T event (Cretaceous-Tertiary Mass Extinction event). Many geologists and paleontologists now think that a large asteroid or comet impacting the Earth must have caused a global catastrophe that led to this extensive loss of life.

    The Chicxulub crater in the Yucatan region of Mexico is a good candidate for the ancient point of impact. The crater is the right age – 65 million years old – and it is consistent with the ...

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  1. Swept Away: Evidence of Erosion on Mars


    Based on a Washington University in St. Louis press release

    Massive erosion shaped the surface of Mars, according to planetary scientists at Washington University in St. Louis. While hunting for safe but geologically-rich landing sites for NASA’s 2003 Mars Exploration Rover (MER) missions, researchers have combed images of the sandy plains in a region of Mars called Arabia Terra.

    Brian M. Hynek, doctoral candidate in Earth and Planetary Sciences, and Roger J. Phillips, Ph.D., professor of earth and planetary sciences and director of Washington University’s McDonnell Center for the Space Sciences, suggest that early in Mars’ history, western ...

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  1. Watching Earth Breathe


    Based on a NASA press release

    The first continuous global observations of the biological engine that drives life on Earth – the countless forms of plants that cover the land and oceans – were published in the March 30 issue of the journal Science.

    This study is based on the first three years of daily observations of ocean algae and land plants from the Sea-viewing Wide Field-of-View Sensor, or SeaWiFS, mission, creating the most comprehensive global biological record ever assembled. Scientists will use the new record of the Earth’s surface to study the fate of carbon in the atmosphere, the ...

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  1. Cold Clouds and Water in Space


    Adapted from a European Space Agency press release

    Astronomers have known for decades that there is a lot of water in space. Hydrogen is the most common element in the Universe, and oxygen is made in stars and dispersed by events such as supernova explosions. The two elements mix in star-forming clouds and form large amounts of water (H2O). But because astronomers couldn’t measure gaseous water in cold clouds in space, they couldn’t be sure of the exact amount of water in those regions.

    “We’ve known for a long time that there is a lot of water ...

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  1. Tropical Glaciers


    Based on a Penn State University press release

    Glacial deposits that formed on tropical land areas during snowball Earth episodes around 600 million years ago, lead to questions about how the glaciers that left the deposits were created. Now, Penn State geoscientists believe that these glaciers could only have formed after the Earth’s oceans were entirely covered by thick sea ice.

    “There is strong geologic evidence of tropical glaciation at sea level during those times,” Dr. David Pollard, research associate, Penn State College of Earth and Mineral Sciences’ Environmental Institute, told attendees at the spring meeting of the American ...

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  1. Did Hades Freeze Over?


    Initially, the surface of our planet was a fiery, molten stew. These early hellish conditions inspired scientists to call the time period from 4.5 to 3.8 billion years ago the “Hadean” era.

    But the Earth was not molten all throughout the Hadean. Within a few million years, the crust cooled and water vapor rained down to form the oceans, although the inside of the planet still remained very hot. It is thought that life soon after may have made its first appearance on Earth, either in the newly formed oceans, or in clay or rocks within the Earth’s ...

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  1. A Taste for Comet Water


    Based on an article by Science@NASA

    Last year comet C/1999 S4 (better known as “Comet LINEAR”) surprised astronomers by breaking apart as it passed near the Sun. Now the long-dead comet has surprised them again: New research shows Comet LINEAR was likely made up of water with the same isotopic composition as water found here on Earth. The finding supports a controversial idea that cometary impacts billions of years ago could have provided most of the water in Earth’s oceans.

    “The idea that comets seeded life on Earth with water and essential molecular building blocks is hotly ...

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  1. Growing Glowing Martian Mustard


    Adapted from a University of Florida press release

    A team of University of Florida scientists has genetically modified a tiny plant to send reports back from Mars in a most unworldly way: by emitting an eerie, fluorescent glow.

    The scientists have proposed an experiment that would send 10 varieties of the plant to the Red Planet as a Mars “Scout” mission. Scout missions are focused high-priority science experiments that can be achieved for less than $300 million apiece.

    The plant experiment, which is funded by NASA’s Human Exploration and Development in Space program, may be a first step toward ...

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  1. The Mass Extinction That Left the Dinosaurs Standing


    Adapted from a University of Washington press release

    A mass extinction about 200 million years ago, which destroyed at least half of the species on Earth, happened very quickly and is demonstrated in the fossil record by the collapse of one-celled organisms called protists, according to new research led by a University of Washington paleontologist.

    “Something suddenly killed off more than 50 percent of all species on Earth, and that led to the age of dinosaurs,” said Peter Ward, a UW Earth and space sciences professor.

    Evidence indicates the massive die-off was linked with an abrupt drop in productivity ...

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  1. Galactic Habitable Zones


    Our Milky Way Galaxy is unusual in that it is one of the most massive galaxies in the nearby universe. Our Solar System also seems to have qualities that make it rather unique. According to Guillermo Gonzalez, Assistant Professor of Astronomy at the University of Washington, these qualities make the Sun one of the few stars in the Galaxy capable of supporting complex life.

    For one thing, the Sun is composed of the right amount of “metals.” (Astronomers refer to all elements heavier than hydrogen and helium as “metals.”) Moreover, the Sun’s circular orbit about the galactic center ...

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  1. Raising Baby Tubeworms


    Based on a Woods Hole Oceanographic Institution press release.

    For nearly 25 years, scientists have wondered how giant red-tipped tubeworms and other exotic marine life found at hydrothermal vents on the deep sea floor get from place to place and how long their larva survive in a cold, eternally dark place. Now Woods Hole Oceanographic Institution biologist Lauren Mullineaux and colleagues have helped answer those questions.

    In a paper published May 3 in the scientific journal Nature entitled “Larval Dispersal Potential of the Tubeworm Riftia pachyptila at Deep-Sea Hydrothermal Vents”, Mullineaux and colleagues provide the first direct answer to the ...

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  1. Life's Baby Steps


    Based on a Carnegie Institution of Washington press release

    Billions of years ago, amino acids somehow linked together to form chainlike molecules. This linkage was a vital step in the development of proteins, which are found in all living systems today.

    Now Robert Hazen and Timothy Filley of the Geophysical Laboratory of the Carnegie Institution of Washington, and Glenn Goodfriend of George Washington University have discovered what may be a key step in this process – a step that has baffled researchers for more than a half a century. Their work, supported by NASA’s Astrobiology Institute and the Carnegie ...

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  1. How Jupiter Got Big


    How did the largest planet in our solar system form?

    The traditional view is that Jupiter first formed a rocky core, several times the size of Earth, which then attracted a still larger outer envelope of gas. This process is known as “accretion.”

    But there are problems with this model. The major problem is that if the large, gaseous planet did form by the gradual accretion of material, it would have taken a very long time to develop. Current estimates range between 10 million and 1 billion years. However, recent observations of distant stars suggest that planets have at ...

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  1. Unpuzzling Proteins


    Based on a press release from NASA Ames Research Center

    Thanks to a new supercomputer, scientists may be a step closer to understanding one of nature’s more difficult puzzles. Scientists at NASA Ames Research Center are using the SGI 512-processor Origin 3000, the most powerful parallel supercomputer of its kind, to try to determine the structure of proteins.

    Proteins play a fundamental role in living cells, acting as catalysts for all chemical reactions. Proteins also act as a kind of “nervous system” for a cell, transmitting signals from the outside environment. They assist in transporting nutrients into the cell, and ...

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  1. Space Weather on Mars


    Based on a Science @ NASA story by Dr. Tony Phillips

    Alien planets have alien weather.

    Take Mars, for example. A morning weather report on the Red Planet might sound like this:

    “Good morning, Martians! It looks like another solar storm heading our way. An X-class solar flare exploded this morning and proton counts have soared 1000-fold. More of the deadly particles are en route, so don’t leave shelter today without your radiation suit!”

    “Coming up next, the sunspot report, right after this word from our sponsor: Levi’s Relaxed Fit LeadPants.”

    It doesn’t sound much like the forecasts we ...

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