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    Category Astronomy/Space

    Asymmetric Structure in the Supermassive Black Hole at the Galaxy’s Center

    January 9, 2017, Categories  Astronomy/Space

    A multi-wavelength image of the field around Sagitarrius A*, the supermassive black hole at the center of the Milky Way galaxy (SgrA* is an imperceptible speck located at the center of this large field of sky). Astronomers have used an array of millimeter-wave telescope facilities to detect a small asymmetry that might be associated with the shadow of the black hole. Credit: NASA

    A multi-wavelength image of the field around Sagitarrius A*, the supermassive black hole at the center of the Milky Way galaxy (SgrA* is an imperceptible speck located at the center of this large field of sky). Astronomers have used an array of millimeter-wave telescope facilities to detect a small asymmetry that might be associated with the shadow of the black hole. Credit: NASA

    The supermassive black hole candidate at the center of our Galaxy (associated with the radio source Sgr A*) is a prime candidate for studying the physical phenomena associated with accretion on to a supermassive black hole...

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    Hubble Provides Interstellar Road Map for Voyagers’ Galactic Trek

    January 8, 2017, Categories  Astronomy/Space

    Voyager's view of solar system (artist's concept). In this illustration, NASA's Voyager 1 spacecraft has a bird's-eye view of the solar system. The circles represent the orbits of the major outer planets: Jupiter, Saturn, Uranus, and Neptune. Launched in 1977, Voyager 1 visited the planets Jupiter and Saturn. The spacecraft is now 13 billion miles from Earth, making it the farthest and fastest-moving human-made object ever built. In fact, Voyager 1 is now zooming through interstellar space, the region between the stars that is filled with gas, dust, and material recycled from dying stars. NASA's Hubble Space Telescope is observing the material along Voyager's path through space. Credit: NASA, ESA, and G. Bacon (STScI)

    Voyager’s view of solar system (artist’s concept). In this illustration, NASA’s Voyager 1 spacecraft has a bird’s-eye view of the solar system. The circles represent the orbits of the major outer planets: Jupiter, Saturn, Uranus, and Neptune. Launched in 1977, Voyager 1 visited the planets Jupiter and Saturn. The spacecraft is now 13 billion miles from Earth, making it the farthest and fastest-moving human-made object ever built. In fact, Voyager 1 is now zooming through interstellar space, the region between the stars that is filled with gas, dust, and material recycled from dying stars. NASA’s Hubble Space Telescope is observing the material along Voyager’s path through space. Credit: NASA, ESA, and G. Bacon (STScI)

    NASA’s 2 Voyager spacecraft are hurtling through unexplored territory on...

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    Hubble Captures ‘Shadow Play’ caused by possible Planet

    January 8, 2017, Categories  Astronomy/Space

    These images, taken a year apart by NASA's Hubble Space Telescope, reveal a shadow moving counterclockwise around a gas-and-dust disk encircling the young star TW Hydrae. The two images at the top, taken by the Space Telescope Imaging Spectrograph, show an uneven brightness across the disk. Through enhanced image processing (images at bottom), the darkening becomes even more apparent. These enhanced images allowed astronomers to determine the reason for the changes in brightness. The dimmer areas of the disk, at top left, are caused by a shadow spreading across the outer disk. The dotted lines approximate the shadow's coverage. The long arrows show how far the shadow has moved in a year (from 2015-2016), which is roughly 20 degrees. Based on Hubble archival data, astronomers determined that the shadow completes a rotation around the central star every 16 years. They know the feature is a shadow because dust and gas in the disk do not orbit the star nearly that quickly. So, the feature must not be part of the physical disk. The shadow may be caused by the gravitational effect of an unseen planet orbiting close to the star. The planet pulls up material from the main disk, creating a warped inner disk. The twisted disk blocks light from the star and casts a shadow onto the disk's outer region. Credit: NASA, ESA, and J. Debes (STScI)

    These images, taken a year apart by NASA’s Hubble Space Telescope, reveal a shadow moving counterclockwise around a gas-and-dust disk encircling the young star TW Hydrae. The two images at the top, taken by the Space Telescope Imaging Spectrograph, show an uneven brightness across the disk. Through enhanced image processing (images at bottom), the darkening becomes even more apparent. These enhanced images allowed astronomers to determine the reason for the changes in brightness. The dimmer areas of the disk, at top left, are caused by a shadow spreading across the outer disk. The dotted lines approximate the shadow’s coverage. The long arrows show how far the shadow has moved in a year (from 2015-2016), which is roughly 20 degrees...

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    Solar Storms could Spark Soils at Moon’s Poles

    January 7, 2017, Categories  Astronomy/Space

    Illustration showing how solar storms charge lunar soil

    Illustration showing how solar energetic particles may cause dielectric breakdown in lunar regolith in a permanently shadowed region (PSR). Tiny breakdown events could occur throughout the floor of the PSR. Credits: NASA/Andrew Jordan

    Powerful solar storms can charge up the soil in frigid, permanently shadowed regions near the lunar poles, and may possibly produce “sparks” that could vaporize and melt the soil, perhaps as much as meteoroid impacts. This alteration may become evident when analyzing future samples from these regions that could hold the key to understanding the history of the moon and solar system.

    The moon has almost no atmosphere, so its surface is exposed to the harsh space environment...

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