Meteorites,Comets and Asteroids

  • Habitability: Betting on 37 Gem
    What star meets the current best guesses for habitability? This fascinating question is part of an ongoing research survey, in preparation for NASA's Terrestrial Planet Finder mission. The answer, according to the largest such classification so far attempted, is the 37th brightest star in
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  • Spaceguard: Five Years
    The 1998 initiative called Spaceguard aims to survey 90% of the near-earth objects, including those that might pose a potential collision risk. At its halfway point, after five years, a new NASA study suggests to extend its goals to include even smaller risks than a
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  • Discovering New Worlds
    Few modern scientific adventures can rival what is currently the task of those discovering new planets. While most of the hundred or so new worlds found so far have been found using the planet's inferred influence on its parent star's gravitational wobble, a few have
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  • Reading Rosetta
    The first mission to land a man-made object on surface of comet is slated for launch early next year. The mission, called Rosetta, seeks to understand mysterious nature of these icy rocks. Scientists have a number of challenges in accomplishing this feat, not least of
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  • Coma for Halley’s Comet
    Seventeen years after the last passage of Comet Halley, the Very Large Telescope at Paranal (Chile) has captured a unique image of this famous object as it cruises through the outer solar system. It is completely inactive in this cold environment.
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  • Star Bright: Part II
    In Part I of this article, the differences between typical stars, brown dwarfs and sub-brown dwarfs were discussed. Stars have a mass of 75 Jupiters or greater, brown dwarfs have a mass between 13 and 75 Jupiters, and sub-brown dwarfs are less than 13 Jupiter
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  • Star Bright: Part I
    Starlight aside, one way to distinguish between stars and planets is to have them weigh in. Stars need a hefty amount of mass to fuse hydrogen, while planets are mere dust motes in comparison. But over past few years, astronomers found planetary-mass objects
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  • Hotter Stars, Habitable Planets?
    Our solar system offers the best chances for life to evolve on its inner planets, but astronomers also wonder if a hotter star than ours might still sustain liquid water--and potential biology--for a more distant orbiting planet. If such a solar system can be triangulated
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  • Tiny Planet SIM
    The challenges of observing a tiny planet against the vast star background and the brightness of a parent sun has not discouraged planet finders. In the coming years, six new space-borne missions are slated for a closer look at the problem.
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  • Buffer Zone Brackets Impact Risks?
    Most estimates for the terrestrial dangers from a large asteroid collision have assumed a pancake model for what happens when the large stone first hits the Earth's atmosphere. But a recent simulation applying a fragmentation model shows a dramatically lower risk: most debris may
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  • Planets Need Heavy-Metal
    Astronomers have previously estimated that around five percent of stars may have planets, but a survey by Berkeley planet finders has refined this classification. If a star is rich in metals, particularly iron and other heavy metals, then it stands a remarkable one-in-five chance of
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  • Interview with Neville Woolf: Part II
    This is the second of a two-part interview with Neville Woolf, a Professor of Astronomy at the University of Arizona. Woolf is the principal investigator of one of the lead teams recently awarded a five-year grant by the NASA Astrobiology Institute (NAI) to conduct astrobiology-related
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  • Interview with Neville Woolf
    This is the first of a two-part interview with Neville Woolf, a Professor of Astronomy at the University of Arizona. Woolf is the principal investigator of one of the lead teams recently awarded a five-year grant by the NASA Astrobiology Institute (NAI) to conduct astrobiology-related
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  • Ancient Planet Discovered
    Using the Hubble Space Telescope, astronomers have identified the oldest and most distant known planet orbiting two burned-out stars. Its sky location in the constellation Scorpius places the planet as the M4 globular cluster. The discovered world is also the only planet found to orbit
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  • Rock, Scissors, Paper and Water
    A recent European conference discussed what a new class of planetary search candidates called 'waterworlds' might require: foremost after water itself, for life to originate elsewhere on a distant world depends on a rocky core and organic pulp.
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