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Astronomy Picture of the Day (General/Chat)

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  • Noctilucent Clouds and Comet NEOWISE (Astronomy Picture of the Day)

    07/09/2020 8:25:29 PM PDT · by MtnClimber · 7 replies
    APOD.NASA ^ | 9 Jul, 2020 | Emmanuel Paoly/NASA
    Explanation: These silvery blue waves washing over a tree-lined horizon in the eastern French Alps are noctilucent clouds. From high in planet Earth's mesosphere, they reflect sunlight in this predawn skyscape taken on July 8. This summer, the night-shining clouds are not new to the northern high-latitudes. Comet NEOWISE is though. Also known as C/2020 F3, the comet was discovered in March by the Earth-orbiting Near Earth Object Wide-field Infrared Survey Explorer (NEOWISE) satellite. It's now emerging in morning twilight only just visible to the unaided eye from a clear location above the northeastern horizon.
  • M43: Dust, Gas, and Stars in the Orion Nebula (Astronomy Picture of the Day)

    07/06/2020 10:49:09 PM PDT · by MtnClimber · 19 replies
    APOD.NASA ^ | 6 Jul, 2020 | NASA, Bryan Goff
    Explanation: Unspeakable beauty and unimaginable bedlam can be found together in the Orion Nebula Arguably the most famous of all astronomy nebulas, the Great Nebula in Orion is an immense interstellar molecular cloud only 1500 light-years away. In the featured deep image shown in assigned colors, the part of the nebula's center known as M43 is shown as taken by the Hubble Space Telescope. The Great Nebula in Orion can be found with the unaided eye near the easily identifiable belt of three stars in the popular constellation Orion. The entire Orion Nebula, including both M42 and M43 spans about...
  • Saturn's Northern Hexagon

    07/06/2020 8:53:41 PM PDT · by MtnClimber · 35 replies
    APOD.NASA ^ | 5 Jul, 2020 | NASA/Cassini Imaging Team
    Explanation: Why would clouds form a hexagon on Saturn? Nobody is sure. Originally discovered during the Voyager flybys of Saturn in the 1980s, nobody has ever seen anything like it anywhere else in the Solar System. Acquiring its first sunlit views of far northern Saturn in late 2012, the Cassini spacecraft's wide-angle camera recorded this stunning, false-color image of the ringed planet's north pole. The composite of near-infrared image data results in red hues for low clouds and green for high ones, giving the Saturnian cloudscape a vivid appearance. This and similar images show the stability of the hexagon even...
  • Portrait of NGC 3628 (Astronomy Picture of the Day)

    07/03/2020 9:27:08 PM PDT · by MtnClimber · 11 replies
    NASA ^ | June 4, 2020 | Stefano Cancelli (1963-2020), Paul Mortfield
    Explanation: Sharp telescopic views of NGC 3628 show a puffy galactic disk divided by dark dust lanes. Of course, this deep portrait of the magnificent, edge-on spiral galaxy puts some astronomers in mind of its popular moniker, the Hamburger Galaxy. It also reveals a small galaxy nearby, likely a satellite of NGC 3628, and a faint but extensive tidal tail. The drawn out tail stretches for about 300,000 light-years, even beyond the right edge of the wide frame. NGC 3628 shares its neighborhood in the local universe with two other large spirals M65 and M66 in a grouping otherwise known...
  • Bright Planetary Nebula NGC 7027 from Hubble (Astronomy Picture of the Day)

    06/30/2020 8:09:50 PM PDT · by MtnClimber · 11 replies
    APOD.NASA ^ | 30 Jun, 2020 | NASA/Joel Kastner
    Explanation: What created this unusual planetary nebula? NGC 7027 is one of the smallest, brightest, and most unusually shaped planetary nebulas known. Given its expansion rate, NGC 7027 first started expanding, as visible from Earth, about 600 years ago. For much of its history, the planetary nebula has been expelling shells, as seen in blue in the featured image. In modern times, though, for reasons unknown, it began ejecting gas and dust (seen in red) in specific directions that created a new pattern that seems to have four corners. These shells and patterns have been mapped in impressive detail by...
  • Europa and Jupiter from Voyager 1 (Astronomy Picture of the Day)

    06/28/2020 8:35:47 PM PDT · by MtnClimber · 19 replies
    APOD.NASA ^ | 28 Jun, 2020 | Alexis Tranchandon / Solaris / NASA
    Explanation: What are those spots on Jupiter? Largest and furthest, just right of center, is the Great Red Spot -- a huge storm system that has been raging on Jupiter possibly since Giovanni Cassini's likely notation of it 355 years ago. It is not yet known why this Great Spot is red. The spot toward the lower left is one of Jupiter's largest moons: Europa. Images from Voyager in 1979 bolster the modern hypothesis that Europa has an underground ocean and is therefore a good place to look for extraterrestrial life. But what about the dark spot on the upper...
  • Watch a 10-Year Time Lapse of Sun From NASA’s SDO

    06/25/2020 8:20:20 PM PDT · by BenLurkin · 10 replies
    NASA ^ | 06/24/2020
    As of June 2020, NASA’s Solar Dynamics Observatory – SDO – has now been watching the Sun non-stop for over a full decade. From its orbit in space around Earth, SDO has gathered 425 million high-resolution images of the Sun, amassing 20 million gigabytes of data over the past 10 years. This information has enabled countless new discoveries about the workings of our closest star and how it influences the solar system. With a triad of instruments, SDO captures an image of the Sun every 0.75 seconds. The Atmospheric Imaging Assembly (AIA) instrument alone captures images every 12 seconds at...
  • The Lively Center of the Lagoon Nebula (Astronomy Picture of the Day)

    06/19/2020 8:57:42 PM PDT · by MtnClimber · 15 replies
    APOD.NASA ^ | 1 Jun, 2020 | NASA/Diego Gravinese
    Explanation: The center of the Lagoon Nebula is a whirlwind of spectacular star formation. Visible near the image center, at least two long funnel-shaped clouds, each roughly half a light-year long, have been formed by extreme stellar winds and intense energetic starlight. A tremendously bright nearby star, Herschel 36, lights the area. Vast walls of dust hide and redden other hot young stars. As energy from these stars pours into the cool dust and gas, large temperature differences in adjoining regions can be created generating shearing winds which may cause the funnels. This picture, spanning about 15 light years, features...
  • NGC 2359: Thor's Helmet (Astronomy Picture of the Day)

    06/12/2020 6:21:08 PM PDT · by MtnClimber · 26 replies
    APOD.NASA ^ | 2020 June 12 | NASA/Martin Pugh
    Explanation: NGC 2359 is a helmet-shaped cosmic cloud with wing-like appendages popularly called Thor's Helmet. Heroically sized even for a Norse god, Thor's Helmet is about 30 light-years across. In fact, the helmet is more like an interstellar bubble, blown as a fast wind from the bright, massive star near the bubble's center inflates a region within the surrounding molecular cloud. Known as a Wolf-Rayet star, the central star is an extremely hot giant thought to be in a brief, pre-supernova stage of evolution. NGC 2359 is located about 15,000 light-years away in the constellation of the Great Overdog. The...
  • Jupiter in Infrared from Gemini (Astronomy Picture of the Day)

    06/09/2020 8:26:46 PM PDT · by MtnClimber · 18 replies
    APOD.NASA ^ | 13 May, 2020 | International Gemini Observatory/NASA
    Explanation: In infrared, Jupiter lights up the night. Recently, astronomers at the Gemini North Observatory in Hawaii, USA, created some of the best infrared photos of Jupiter ever taken from Earth’s surface, pictured. Gemini was able to produce such a clear image using a technique called lucky imaging, by taking many images and combining only the clearest ones that, by chance, were taken when Earth's atmosphere was the most calm. Jupiter’s jack-o’-lantern-like appearance is caused by the planet’s different layers of clouds. Infrared light can pass through clouds better than visible light, allowing us to see deeper, hotter layers of...
  • Orion over Argentine Mountains (Astronomy Picture of the Day)

    06/08/2020 9:54:49 PM PDT · by MtnClimber · 7 replies
    APOD.NASA ^ | 9 Apr, 2020 | Nicolas Tabbush/NASA
    Explanation: Do you recognize the constellation of Orion? It may be harder than usual in today's featured image because the camera has zoomed in on the center, and the exposure is long enough to enhance nebulas beyond what the unaided human eye can see. Still, once you become oriented, you can see Orion's three belt stars lined up vertically near the image center, and even locate the familiar Orion Nebula on the upper left. Famous faint features that are also visible include the dark Horsehead Nebula indentation near the image center, and the dusty Flame Nebula just to its right....
  • Halo of the Cat's Eye (Astronomy Picture of the Day)

    06/07/2020 9:07:28 PM PDT · by MtnClimber · 9 replies
    APOD.NASA ^ | R. Corradi/NASA
    Explanation: The Cat's Eye Nebula (NGC 6543) is one of the best known planetary nebulae in the sky. Its haunting symmetries are seen in the very central region of this stunning false-color picture, processed to reveal the enormous but extremely faint halo of gaseous material, over three light-years across, which surrounds the brighter, familiar planetary nebula. Made with data from the Nordic Optical Telescope in the Canary Islands, the composite picture shows extended emission from the nebula. Planetary nebulae have long been appreciated as a final phase in the life of a Sun-like star. Only much more recently however, have...
  • Comet PanSTARRs and the Galaxies (Astronomy Picture of the Day)

    06/06/2020 5:27:37 AM PDT · by MtnClimber · 9 replies
    APOD/NASA ^ | 6 Jun, 2020 | Dan Bartlett/NASA
    Explanation: Comet PanSTARRs, C/2017 T2, shared this stunning telescopic field of view with galaxies M81 and M82 on May 22/23. Of course, the galaxies were some 12 million light-years distant and the comet about 14 light-minutes away, seen in planet Earth's sky toward the Big Dipper. A new visitor from the Oort Cloud, this Comet PanSTARRs was discovered in 2017 by the PanSTARRs survey telescope when the comet was over 1 light-hour from the Sun, almost as distant as the orbit of Saturn. With a beautiful coma and dust tail, this comet has been a solid northern hemisphere performer for...
  • Dragon over Central Park (Astronomy Picture of the Day)

    06/05/2020 8:55:01 PM PDT · by MtnClimber · 7 replies
    APOD/NASA ^ | 5 Jun, 2020 | Stan Honda/NASA
    Explanation: Still bathed in sunlight the International Space Station (ISS) arced through this Manhattan evening sky on May 30. Moving left to right, its bright trail was captured in this composite image with a series of 5 second long exposures. Stars left short trails and lights were reflected in still waters looking toward the north across the Central Park reservoir. Chasing the ISS in low Earth orbit the Crew Dragon spacecraft dubbed Endeavour also left a trail through that urban night. Seen about 6 hours after its launch the spacecraft's faint trail appears above the ISS, shown in the inset...
  • Reflecting the International Space Station (Astronomy Picture of the Day)

    05/28/2020 7:07:12 AM PDT · by MtnClimber · 8 replies
    APOD NASA ^ | 28 May, 2020 | Helmut Schnieder/NASA
    Explanation: Still bathed in sunlight, the International Space Station arced through the evening sky over lake Wulfsahl-Gusborn in northern Germany, just after sunset on March 25. The familiar constellation of Orion can be seen left of the trail of the orbital station's bright passage. On the right, Venus is the brilliant evening star above the western horizon. With the camera fixed to a tripod, this scene was captured in a series of five exposures. How can you tell? The short time delay between the end of one exposure and the beginning of the next leaves small gaps in the ISS...
  • Earth and Moon through Saturn's Rings (NASA Astronomy Picture of the Day)

    05/27/2020 5:28:59 AM PDT · by MtnClimber · 15 replies
    APOD/NASA ^ | 27 May, 2020 | Cassini Imaging Team
    Explanation: What are those dots between Saturn's rings? Our Earth and Moon. Just over three years ago, because the Sun was temporarily blocked by the body of Saturn, the robotic Cassini spacecraft was able to look toward the inner Solar System. There, it spotted our Earth and Moon -- just pin-pricks of light lying about 1.4 billion kilometers distant. Toward the right of the featured image is Saturn's A ring, with the broad Encke Gap on the far right and the narrower Keeler Gap toward the center. On the far left is Saturn's continually changing F Ring. From this perspective,...
  • New Research Suggests the Universe May Be a Giant Loop

    11/08/2019 6:41:15 AM PST · by Red Badger · 116 replies
    www.popularmechanics.com ^ | By Jennifer Leman Nov 5, 2019
    Picture Credit: ESA and the Planck Collaboration ================================================================== New, contested research suggests our universe may actually be a closed loop instead of a vast, never-ending expanse. The theory has drawn sharp criticism from other cosmologists. Confirmation of this theory could completely unravel everything scientists know and understand about our universe. ================================================================= Imagine jetting out into the universe. You sail past Mars, Neptune, and Pluto, far out past the milky way and into the frothy nothingness of space. What might you find if you travelled far enough? Well, you might actually end up right back where you started. There's a small...
  • 35 ‘Astronomy Photographer Of The Year 2019’ Finalists

    09/19/2019 4:58:06 PM PDT · by Openurmind · 12 replies
    Boredpanda ^ | Sep 18 2019 | Li Nefas and James Caunt
    Astrophotography is probably one of the most difficult and specialized types of photography to try your hand at, but if you manage to get it right the rewards are some of the most astonishingly breathtaking images you are ever likely to see. The Royal Observatory Greenwich has just revealed the winners of its annual Astronomy Photographer of the Year competition, and the quality of the entrants was nothing short of spectacular. This year the competition attracted 4,602 entries from 90 different countries across the world, all presenting the universe in a new light and vying for the coveted prize of...
  • APOD: Lunations (09/12/18)

    09/28/2018 9:56:51 AM PDT · by zeugma · 4 replies
    Astronomy Picture of the Day ^ | 9/12/18 | NASA's Scientific Visualization Studio;
    Our Moon's appearance changes nightly. As the Moon orbits the Earth, the half illuminated by the Sun first becomes increasingly visible, then decreasingly visible. The featured video animates images taken by NASA's Moon-orbiting Lunar Reconnaissance Orbiter to show all 12 lunations that appear this year, 2018. A single lunation describes one full cycle of our Moon, including all of its phases. A full lunation takes about 29.5 days, just under a month (moon-th). As each lunation progresses, sunlight reflects from the Moon at different angles, and so illuminates different features differently. During all of this, of course, the Moon always...
  • 'Double asteroid' zooming by Earth at 43,000 mph captured in amazing photo

    06/04/2019 6:01:30 PM PDT · by ETL · 52 replies
    FoxNews.com/science ^ | June 3, 2019 | Stephen Sorace | Fox News
    A unique “double asteroid” was photographed by a powerful telescope as it whizzed by Earth last month at over 43,000 mph. The asteroid, classified as 1999 KW4, is made up of two components — a larger body orbited by a smaller one separated by about 1.6 miles. It got as close as 3.2 million miles to Earth on May 25 — about 14 times the distance from Earth to the Moon, the European Southern Observatory (ESO) said in a news release Monday. The double asteroid, which has an orbit well known to scientists, is not an impact threat to Earth,...