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    Category Astronomy/Space

    Mars Gullies likely Not formed by Liquid Water

    August 12, 2016, Categories  Astronomy/Space

    The highly incised gullies on the eastern rim of the 150 km × 125 km Hale crater (located at 35.7°S, 323.4°E) as seen in the HiRISE image (top) resemble gullies on Earth and appear to have been carved by liquid water. However, when the gullies are observed with the addition of mineralogical information from CRISM (bottom), unaltered mafic material (light blue) from the crater rim is carved and transported downslope along the gully channels. No hydrated minerals are observed within the gullies in the CRISM image, indicating limited to no interaction of the mafic material with liquid water. These findings suggest that a different mechanism that does not involve liquid water may be responsible for carving these gullies on Mars. The top image is a HiRISE image (HiRISE PSP_002932_1445), and the bottom image is the same HiRISE image with a CRISM mineral map (CRISM FRT00004AF7) overlaid on top. Credit: NASA/JPL/Univ. of Arizona/JHUAPL

    The highly incised gullies on the eastern rim of the 150 km × 125 km Hale crater (located at 35.7°S, 323.4°E) as seen in the HiRISE image (top) resemble gullies on Earth and appear to have been carved by liquid water. However, when the gullies are observed with the addition of mineralogical information from CRISM (bottom), unaltered mafic material (light blue) from the crater rim is carved and transported downslope along the gully channels. No hydrated minerals are observed within the gullies in the CRISM image, indicating limited to no interaction of the mafic material with liquid water. These findings suggest that a different mechanism that does not involve liquid water may be responsible for carving these gullies on Mars...

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    Stellar Lab in Sagittarius

    August 11, 2016, Categories  Astronomy/Space

    The star cluster Messier 18 and its surroundings. Credit: ESO

    The star cluster Messier 18 and its surroundings. Credit: ESO

    The small smattering of bright blue stars in the upper left of this vast new 615 megapixel ESO image is the perfect cosmic laboratory in which to study the life and death of stars. Known as Messier 18 this star cluster contains stars that formed together from the same massive cloud of gas and dust. This image, which also features red clouds of glowing hydrogen and dark filaments of dust, was captured by the VLT Survey Telescope (VST) at ESO’s Paranal Observatory in Chile.

    Messier 18 was discovered and catalogued in 1764 by Charles Messier during his search for comet-like objects...

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    Cassini finds Flooded Canyons on Saturn’s moon Titan

    August 11, 2016, Categories  Astronomy/Space

    These images from the Radar instrument aboard NASA's Cassini spacecraft show the evolution of a transient feature in the large hydrocarbon sea named Ligeia Mare on Saturn's moon Titan. Credit: NASA/JPL-Caltech/ASI/Cornell

    These images from the Radar instrument aboard NASA’s Cassini spacecraft show the evolution of a transient feature in the large hydrocarbon sea named Ligeia Mare on Saturn’s moon Titan. Credit: NASA/JPL-Caltech/ASI/Cornell

    NASA’s Cassini spacecraft has found deep, steep-sided canyons on Titan that are flooded with liquid hydrocarbons. The finding represents the first direct evidence of the presence of liquid-filled channels on Titan, as well as the first observation of canyons hundreds of meters deep. Scientists analyzed Cassini data from a close pass the spacecraft made over Titan in May 2013. During the flyby, Cassini’s radar focused on channels that branch out from the large, northern sea Ligeia Mare.

    The Cassini observations reveal that the channels – in particular, a network of them na...

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    Watch a Tiny Space Rocket Work

    August 10, 2016, Categories  Astronomy/Space

    The tree-like formations in this molten salt formed under the high-radiation of a transmission electron microscope beam; the jet of ions from the material could serve as a thruster for a nanosatellite Credit: Michigan Tech, Kurt Terhune

    The tree-like formations in this molten salt formed under the high-radiation of a transmission electron microscope beam; the jet of ions from the material could serve as a thruster for a nanosatellite Credit: Michigan Tech, Kurt Terhune

    Researchers have operated a tiny proposed satellite ion rocket under a microscope to see how it works. The rocket, called an electrospray thruster, is a drop of molten salt. When electricity is applied, it creates a field on the tip of the droplet, until ions begin streaming off the end. The force created by the rocket is less than the weight of a human hair, but in the vacuum of space it is enough to push a small object forward with a constant acceleration...

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