Milky Way over Chilean Volcanoes
Sometimes, the sky mimics the ground. Taken in 2017 May from the Atacama Desert in Chile, the foreground of the featured image encompasses the dipping edge of the caldera of an extinct volcano. Poetically echoing the dip below is the arch of our Milky Way Galaxy above. Many famous icons dot this southern nighttime vista, including the center of our Milky Way Galaxy on the far left, the bright orange star Antares also on the left, the constellation of the Southern Cross near the top of the arch, and the red-glowing Gum Nebula on the far right. Just above the horizon and splitting two distant volcanic peaks near the image center is the Large Magellanic Cloud -- the largest satellite galaxy of the Milky Way.
Image Credit: Carlos Eduardo Fairbairn
NGC 2442: Galaxy in Volans
Distorted galaxy NGC 2442 can be found in the southern constellation of the flying fish, (Piscis) Volans. Located about 50 million light-years away, the galaxy's two spiral arms extending from a pronounced central bar have a hook-like appearance in wide-field images. But this mosaicked close-up, constructed from Hubble Space Telescope and European Southern Observatory data, follows the galaxy's structure in amazing detail. The sharp image data also reveal more distant background galaxies seen right through NGC 2442's star clusters and nebulae. The image spans about 75,000 light-years at the estimated distance of NGC 2442.
Image Credit: Robert Gendler
Perseid by the SeaJust after moonrise on August 12 this grain of cosmic sand fell by the sea, its momentary flash part of the annual Perseid Meteor Shower. To create the Perseid meteors, dust along the orbit of periodic comet Swift-Tuttle is swept up by planet Earth. The cometary debris plows through the atmosphere at nearly 60 kilometers per second and is quickly vaporized at altitudes of 100 kilometers or so. Perseid meteors are often bright and colorful, like the one captured in this sea and night skyscape. Against starry sky and faint Milky Way the serene view looks south and west across the Adriatic Sea, from the moonlit Dalmatian coast toward the island of Brac.
Image Credit: Tamas Ladanyi
Charon Flyover from New HorizonsWhat if you could fly over Pluto's moon Charon -- what might you see? The New Horizons spacecraft did just this in 2015 July as it zipped past Pluto and Charon with cameras blazing. The images recorded allowed for a digital reconstruction of much of Charon's surface, further enabling the creation of fictitious flights over Charon created from this data. One such fanciful, minute-long, time-lapse video is shown here with vertical heights and colors of surface features digitally enhanced. Your journey begins over a wide chasm that divides different types of Charon's landscapes, a chasm that might have formed when Charon froze through. You soon turn north and fly over a colorful depression dubbed Mordor that, one hypothesis holds, is an unusual remnant from an ancient impact. Your voyage continues over an alien landscape rich with never-before-seen craters, mountains, and crevices. The robotic New Horizons spacecraft has now been targeted at Kuiper Belt object 2014 MU 69, which it should zoom past on New Year's Day 2019.
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Albert Einstein's general theory of relativity, published over 100 years ago, predicted the phenomenon of gravitational lensing. And that's what gives these distant galaxies such a whimsical appearance, seen through the looking glass of X-ray and optical image data from the Chandra and Hubble space telescopes. Nicknamed the Cheshire Cat galaxy group, the group's two large elliptical galaxies are suggestively framed by arcs. The arcs are optical images of distant background galaxies lensed by the foreground group's total distribution of gravitational mass. The two large elliptical "eye" galaxies represent the brightest members of their own galaxy groups which are merging. Their relative collisional speed of nearly 1,350 kilometers/second heats gas to millions of degrees producing the X-ray glow shown in purple hues. Curiouser about galaxy group mergers? The Cheshire Cat group grins in the constellation Ursa Major, some 4.6 billion light-years away.
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