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Astronomy (General/Chat)

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  • Astronomy Picture of the Day - Twilight with Moon and Planets

    02/21/2026 1:25:23 PM PST · by MtnClimber · 9 replies
    NASA ^ | 21 Feb, 2026 | Image Credit & Copyright: Tunc Tezel (TWAN)
    Explanation: Only two days after the February New Moon's annular eclipse of the Sun, a slender lunar crescent poses above the western horizon after sunset in this wintry twilight skyscape. Its nightside faintly illuminated by earthshine, the young Moon is joined by three bright planets in the mostly clear, early evening skies above the village of Kirazli, Turkiye. Inner planet Venus appears closest to the horizon. Near the beginning of its 2026 performance as planet Earth's evening star, brilliant Venus is seen through the warm sunset glare near picture center. Straight above Venus, innermost planet Mercury is easy to spot...
  • Astronomy Picture of the Day - B93: A Dark Interstellar Ghost

    02/20/2026 11:15:27 AM PST · by MtnClimber · 9 replies
    NASA ^ | 20 Feb, 2026 | Image Credit & Copyright: Christian Bertincourt; Text: Keighley Rockcliffe (NASA GSFC, UMBC CSST, CR
    Explanation: "A ghost in the Milky Way…” says Christian Bertincourt, the astrophotographer behind this striking image of Barnard 93 (B93). The 93rd entry in Barnard’s Catalogue of Dark Nebulae, B93 lies within the Small Sagittarius Star Cloud (Messier 24), where its darkness stands in stark contrast to bright stars and gas in the background. In some ways, B93 is really like a ghost, because it contains gas and dust that was dispersed by the deaths of stars, like supernovas. B93 appears as a dark void not because it is empty, but because its dust blocks the light emitted by more...
  • The Physics That Makes Interstellar Travel IMPOSSIBLE

    02/19/2026 1:56:56 PM PST · by rexthecat · 242 replies
    YouTube ^ | February 6, 2026 | Richard Feynman
    Richard Feynman’s physics reveals why aliens cannot reach Earth. From the absolute limit of the Speed of Light to the Fermi Paradox, discover why Interstellar Travel is impossible and why we are truly alone in the universe. …
  • Astronomy Picture of the Day - IC 2574: Coddington's Nebula

    02/19/2026 11:50:16 AM PST · by MtnClimber · 7 replies
    NASA ^ | 19 Feb, 2026 | Image Credit & Copyright: Dane Vetter
    Explanation: Grand spiral galaxies often seem to get all the glory, flaunting their young, bright, blue star clusters in beautiful, symmetric spiral arms. But small, irregular galaxies form stars too. In fact, dwarf galaxy IC 2574 shows clear evidence of intense star forming activity in its telltale reddish regions of glowing hydrogen gas. Just as in spiral galaxies, the turbulent star-forming regions in IC 2574 are churned by stellar winds and supernova explosions spewing material into the galaxy's interstellar medium and triggering further star formation. A mere 12 million light-years distant, IC 2574 is part of the M81 group of...
  • Astronomy Picture of the Day - Orion's Cradle

    02/18/2026 1:20:39 PM PST · by MtnClimber · 10 replies
    NASA ^ | 18 Feb, 2026 | Image Credit & Copyright: Piotr Czerski
    Explanation: Cradled in red-glowing hydrogen gas, stars are being born in Orion. These stellar nurseries lie at the edge of the giant Orion molecular cloud complex, some 1,500 light-years away. This detailed view spans about 12 degrees across the center of the well-known constellation, with the Great Orion Nebula, the closest large star-forming region, visible toward the lower right. The deep mosaic also includes, near the top center, the Flame Nebula and the Horsehead Nebula. Image data acquired with a hydrogen-alpha filter adds other remarkable features to this wide-angle cosmic vista: pervasive tendrils of energized atomic hydrogen gas and portions...
  • When Quantum Physics Hit A Dead End, GPT-5.2 Found a Hidden Door

    02/17/2026 12:41:44 PM PST · by Twotone · 53 replies
    NDTV Profit ^ | February 16, 2026 | Yukta Baid
    OpenAI's GPT-5.2 has derived a new formula for gluon interactions, overturning assumptions of zero amplitude and advancing theoretical physics. For a long, long time physicists treated this interaction as a cosmic impossibility — a mathematical dead end so absolute it was taught almost with the certainty of Newton's laws and the elegance of Einstein's equations. Zero, in quantum physics, isn't a shrug; it's a verdict. And this particular verdict had stood unchallenged for decades. But every so often, science gets a jolt — a falling apple, a bending beam of starlight… or, in 2026, an AI model that refuses to...
  • Astronomy Picture of the Day - Tails of Comet Wierzchoś

    02/17/2026 11:36:44 AM PST · by MtnClimber · 7 replies
    NASA ^ | 17 Feb, 2026 | Image Credit & Copyright: José J. Chambó; Text: Cecilia Chirenti (NASA GSFC, UMCP, CRESST II)
    Explanation: Some comets are regular guests of our solar neighborhood; others come by only once, never to return. We won’t have another chance to see Comet C/2024 E1 (Wierzchoś), which is currently making its way through the inner Solar System. The hyperbolic orbit of this comet indicates that it will likely become an interstellar traveler. Comet Wierzchoś is today near its closest approach to the Earth, passing roughly the same distance from the Earth as is the Sun. The featured 30-minute exposure was taken last week in Chile and shows a 5-degree long ion tail as well as three shorter...
  • Astronomy Picture of the Day - Unexplained Shocks Around a White Dwarf Star

    02/16/2026 1:04:56 PM PST · by MtnClimber · 13 replies
    NASA ^ | 16 Feb, 2026 | Image Credit: ESO, K. Iłkiewicz & S. Scaringi et al.; Text: Cecilia Chirenti (NASA GSFC, UMCP, CRESS
    Explanation: How is RXJ0528+2838 creating such shock waves? A recently discovered white dwarf star, the farther left of the two largest white spots, RXJ0528+2838, was found 730 light-years away from Earth. Most stars, when done fusing nuclei in their cores for energy, become red giant stars, the cores of which live on as faint dense white dwarfs that slowly cool down for the rest of time. White dwarfs are so dense that the only thing that stops them from collapsing further is quantum mechanics. In about 5 billion years, our Sun will become a white dwarf, too. The featured image,...
  • The Volcano That Could Wipe Out the Greek Islands | Volcano Documentary [44:43]

    02/15/2026 9:52:57 PM PST · by SunkenCiv · 23 replies
    YouTube ^ | December 9, 2025 | Autentic Documentary (inauthentic spelling?)
    This active volcano still spews gas -- and a major eruption could trigger a deadly tsunami. Locals live in its shadow, knowing history could repeat itself. Nisyros is a small, volcanic island and municipality in the Dodecanese group of islands in the Aegean Sea, located between Kos and Tilos. The Volcano That Could Wipe Out the Greek Islands Volcano Documentary | 44:43 Autentic Documentary | 95.8K subscribers | 58,260 views | December 9, 2025
  • Astronomy Picture of the Day - To Fly Free in Space

    02/15/2026 6:40:37 PM PST · by MtnClimber · 18 replies
    NASA ^ | 15 Feb, 2026 | Image Credit: NASA, STS-41B
    Explanation: What would it be like to fly free in space? About 100 meters from the cargo bay of a space shuttle, Bruce McCandless II was living the dream -- floating farther out than anyone had ever been before. Guided by a Manned Maneuvering Unit (MMU), astronaut McCandless, pictured, was floating free in space. During Space Shuttle mission 41-B in 1984, McCandless and fellow NASA astronaut Robert Stewart were the first to experience such an "untethered space walk". The MMU worked by shooting jets of nitrogen and was used to help deploy and retrieve satellites. With a mass over 140...
  • Astronomy Picture of the Day - Roses are Red

    02/15/2026 5:57:56 PM PST · by MtnClimber · 8 replies
    NASA ^ | 14 Feb, 2024 | Image Credit & Copyright: Raffaele Calcagno Text: Keighley Rockcliffe (NASA GSFC, UMBC CSST, CRESST
    Explanation: Roses are red, nebulas are too, and this Valentine's gift is a stunning view! Pictured is a loving look at the Rosette Nebula (NGC 2237): a cosmic bloom of bright young stars sitting atop a stem of glowing hot gas. The rose’s blue-white speckles are among the most luminous stars in the galaxy, with some burning millions of times brighter than the Sun. Their stellar winds sculpt the famed rose shape by pushing gas and dust away from the center. Though only a few million years old, these massive stars are already nearing the end of their lives, while...
  • Astronomy Picture of the Day - NGC 147 and NGC 185

    02/15/2026 4:52:13 PM PST · by MtnClimber · 6 replies
    NASA ^ | 13 Feb, 2026 | Image Credit & Copyright: Chuck Ayoub
    Explanation: Dwarf galaxies NGC 147 (left) and NGC 185 stand side by side in this deep telescopic portrait. The two are not-often-imaged satellite galaxies of M31, the great spiral Andromeda Galaxy, some 2.5 million light-years away. Their separation on the sky, less than one degree across a pretty field of view toward the constellation Cassiopeia, translates to only about 35 thousand light-years at Andromeda's distance, but Andromeda itself is found well outside this frame. Brighter and more famous satellite galaxies of Andromeda, M32 and M110, are seen much closer to the great spiral. NGC 147 and NGC 185 have been...
  • Astronomy Picture of the Day - The Bay of Rainbows

    02/12/2026 12:03:16 PM PST · by MtnClimber · 8 replies
    NASA ^ | 12 Feb, 2026 | Image Credit & Copyright: Olaf Filzinger
    Explanation: Dark, smooth regions that cover the Moon's familiar face are called by Latin names for oceans and seas. That naming convention is historical, though it may seem a little ironic to denizens of the space age who recognize the Moon as a mostly dry and airless world, and the smooth, dark areas as lava-flooded impact basins. For example, this telescopic lunar vista, looks over the expanse of the northwestern Mare Imbrium, or Sea of Rains and into the Sinus Iridum, the Bay of Rainbows. Ringed by the Jura Mountains (montes), the bay is about 250 kilometers across. Seen after...
  • Astronomy Picture of the Day - A Year of Sunspots

    02/11/2026 1:15:19 PM PST · by MtnClimber · 13 replies
    NASA ^ | 11 Feb, 2026 | Image Credit: NASA, SDO; Processing & Copyright: Şenol Şanli & Uğur İkizler; Text: Cecilia Chirenti
    Explanation: How many sunspots can you see? The central image shows the many sunspots that occurred in 2025, month by month around the circle, and all together in the grand central image. Each sunspot is magnetically cooled and so appears dark -- and can last from days to months. Although the featured images originated from NASA's Solar Dynamics Observatory, sunspots can be easily seen with a small telescope or binoculars equipped with a solar filter. Very large sunspot groups like recent AR 4366 can even be seen with eclipse glasses. Sunspots are still counted by eye, but the total number...
  • Astronomy Picture of the Day - In Green Company: Aurora over Norway

    02/10/2026 11:54:34 AM PST · by MtnClimber · 15 replies
    NASA ^ | 10 Feb, 2026 | Image Credit & Copyright: Max Rive
    Explanation: Raise your arms if you see an aurora. With those instructions, two nights went by with, well, clouds -- mostly. On the third night of returning to same peaks, though, the sky not only cleared up but lit up with a spectacular auroral display. Arms went high in the air, patience and experience paid off, and the creative featured image was captured as a composite from three separate exposures. The setting is a summit of the Austnesfjorden (a fjord) close to the town of Svolvear on the Lofoten islands in northern Norway. The year was 2014. This year, our...
  • NASA to let astronauts bring smartphones into space for upcoming missions

    02/08/2026 3:23:19 PM PST · by BenLurkin · 21 replies
    ktla ^ | lily dallow
    Astronauts headed into orbit — and toward the moon — will soon be able to bring their personal smartphones along for the ride. NASA announced this week that crews assigned to upcoming missions, including Crew-12 and Artemis II, will be allowed to fly with modern smartphones, marking a shift from longtime rules that required astronauts to leave personal devices behind while living aboard the International Space Station. In a post on X, NASA Administrator Jared Isaacman said the change is meant to help crews document historic moments and stay connected with loved ones back on Earth. ... Until now, astronauts...
  • Astronomy Picture of the Day - Miranda Revisited

    02/09/2026 1:26:50 PM PST · by MtnClimber · 12 replies
    NASA ^ | 9 Feb, 2026 | Image Credit: NASA, JPL, Voyager 2; Processing & License: Flickr: zelario12; Text: Keighley Rockclif
    Explanation: What is Miranda really like? Visually, old images from NASA's Voyager 2 have been recently combined and remastered to result in the featured image of Uranus's 500-kilometer-wide moon. In the late 1980s, Voyager 2 flew by Uranus, coming close to the cratered, fractured, and unusually grooved moon -- named after a character from Shakespeare’s The Tempest. Scientifically, planetary scientists are using old data and clear images to theorize anew about what shaped Miranda's severe surface features. A leading hypothesis is that Miranda, beneath its icy surface, may have once hosted an expansive liquid water ocean which may be slowly...
  • SpaceX prioritizes lunar 'self-growing city' over Mars project, Musk says

    02/08/2026 8:58:50 PM PST · by E. Pluribus Unum · 29 replies
    Reuters.com ^ | February 8, 20265:43 PM CST | Reuters
    SummarySpaceX shifts focus to lunar city, Mars project delayed Musk cites civilization's future, Moon is faster than Mars SpaceX plans uncrewed lunar landing by March 2027 Feb 8 (Reuters) - Elon Musk said on Sunday that SpaceX has shifted its focus to building a "self‑growing city" on the moon, which could be achieved in less than 10 years. SpaceX still intends to start on Musk's long-held ambition of a city on Mars within five to seven years, he wrote on his X social media platform, "but the overriding priority is securing the future of civilization and the Moon is faster."...
  • Astronomy Picture of the Day - Active Sunspot Region 4366 Crosses the Sun

    02/08/2026 12:29:22 PM PST · by MtnClimber · 10 replies
    NASA ^ | 8 Feb, 2026 | Image Credit & Copyright: Daniel Korona
    Explanation: An unusually active sunspot region is now crossing the Sun. The region, labelled AR 4366, is much larger than the Earth and has produced several powerful solar flares over the past ten days. In the featured image, the region is marked by large and dark sunspots toward the upper right of the Sun's disk. The image captured the Sun over a hill in Zacatecas, Mexico, 5 days ago. AR 4366 has become a candidate for the most active solar region in this entire 11-year solar cycle. Active solar regions are frequently associated with increased auroral activity on the Earth....
  • Astronomy Picture of the Day - Crescent Enceladus

    02/07/2026 10:52:26 AM PST · by MtnClimber · 9 replies
    NASA ^ | 7 Feb, 2026 | Image Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA
    Explanation: Peering from the shadows, the Saturn-facing hemisphere of tantalizing inner moon Enceladus poses in this Cassini spacecraft image. North is up in the dramatic scene captured during November 2016 as Cassini's camera was pointed in a nearly sunward direction about 130,000 kilometers from the moon's bright crescent. In fact, the distant world reflects over 90 percent of the sunlight it receives, giving its surface about the same reflectivity as fresh snow. A mere 500 kilometers in diameter, Enceladus is a surprisingly active moon. Data and images collected during Cassini's flybys have revealed water vapor and ice grains spewing from...