Category Archives: Science

Behold: just one part of the immense interstellar molecular cloud of NGC 1976, aka Messier 42, aka the Great Nebula in Orion: To wit:

…the part of the nebula’s centre 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 40 light years and is located in the same spiral arm of our Galaxy as the Sun.

(Image: NASA, ESA, Hubble, HLA; Reprocessing & Copyright: Bryan Goff)

Previously: Inside Orion

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Behold: a vast hexagonal cloud formation over Saturn’s northern hemisphere. First discovered by Voyager in the 1980s and subsequently observed by Cassini, nothing like it has been found elsewhere in the solar system. To wit:

Acquiring its first sunlit views of far northern Saturn in late 2012, the Cassini spacecraft’s wide-angle camera recorded this stunning, false-colour 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 20+ years after Voyager. Movies of Saturn’s North Pole show the cloud structure maintaining its hexagonal structure while rotating. Unlike individual clouds appearing like a hexagon on Earth, the Saturn cloud pattern appears to have six well defined sides of nearly equal length. Four Earths could fit inside the hexagon. Beyond the cloud tops at the upper right, arcs of the planet’s eye-catching rings appear bright blue.

(Image: NASA, ESA, JPL, SSI, Cassini Imaging Team)

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An extraordinary image captured by a very sensitive camera late last month on a summit of the Vosges mountains in France.

Fireworks? Of a sort, yes. To wit:

Generated over intense thunderstorms, this one about 260 kilometers away, the brief and mysterious flashes have come to be known as red sprites. The transient luminous events are caused by electrical breakdown at altitudes of 50 to 100 kilometers. That puts them in the mesophere, the coldest layer of planet Earth’s atmosphere. The glow beneath the sprites is from more familiar lighting though, below the storm clouds. But on the right, the video frames have captured another summertime apparition from the mesophere. The silvery veins of light are polar mesospheric clouds. Also known as noctilucent or night shining clouds, the icy clouds still reflect the sunlight when the Sun is below the horizon.

(Image: Stephane Vetter (TWAN, Nuits sacrees))

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Behold:  NGC 7027 – one of the smallest, brightest and unusually shaped planetary nebulas known. They say it looks a bit like a Jewel Bug.To wit:

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 recent images from the Wide Field Camera 3 onboard the Hubble Space Telescope. What lies at the nebula’s centre is unknown, with one hypothesis holding it to be a close binary star system where one star sheds gas onto an erratic disk orbiting the other star. NGC 7027, about 3,000 light years away, was first discovered in 1878 and can be seen with a standard backyard telescope toward the constellation of the Swan (Cygnus).

(Image: NASA, ESA, Joel Kastner (RIT) et al.; Processing: Alyssa Pagan (STScI))

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Behold: the central band of the Milky Way reflected in a lake beneath the dark sky of Southern Australia last month. To wit:

Toward the right were both the Small (SMC) and Large (LMC) Magellanic Clouds, satellite galaxies of our Milky Way. Faint multicolored bands of airglow fanned across the night. Numerous bright stars were visible including Antares, while the bright planet Jupiter appears just above the image center. The featured image is a composite of exposures all taken from the same camera and from the same location within 30 minutes in mid-May from the shore of Lake Bonney Riverland in South Australia. Dead trees that extend from the lake were captured not only in silhouette, but reflection, while lights from the small town of Barmera were visible across the lake. In July, Jupiter and Saturn will rise toward the east just as the Sun sets in the west.

(Image: Will Godward)

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For ten years now, NASA’s Solar Dynamics Observatory has been capturing an image of Sol every 0.75 seconds from geosynchronous orbit around the earth. In this mesmeric hour long video, every second represents a day in the sun’s life, with various noteworthy events highlighted. To wit:

12:24, June 5, 2012 — The transit of Venus across the face of the Sun. Won’t happen again until 2117.

13:50, Aug. 31, 2012 — The most iconic eruption of this solar cycle bursts from the lower left of the Sun.

43:20, July 5, 2017 — A large sunspot group spends two weeks crossing the face of the Sun.

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Behold the busy surface and inner orbit of Jupiter. There’s a lot going on. To wit:

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 right? That is a shadow of another of Jupiter’s large moons: Io. Voyager 1 discovered Io to be so volcanic that no impact craters could be found. Sixteen frames from Voyager 1’s flyby of Jupiter in 1979 were recently reprocessed and merged to create the featured image. About 43 years ago, Voyager 1 launched from Earth and started one of the greatest explorations of the Solar System ever.

(Image: NASA, Voyager 1, JPL, Caltech; Processing & License: Alexis Tranchandon / Solaris)

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With last Sunday’s solstice came the northernmost sunset for 2020 and – as an added bonus for some – an annular solar eclipse. Some viewpoints were better than others. To wit:

At maximum eclipse, the New Moon in silhouette created a ring of fire visible along a narrow path at most 85 kilometers wide. The annular eclipse path began in central Africa, crossed south Asia and China, and ended over the Pacific Ocean. But a partial eclipse of the Sun was visible over a much broader region. In Hong Kong, this busy section of Jordan Street looks to the northwest, well-aligned with the track of the near solstice afternoon Sun. The street level view was composited with an eclipse sequence made with a safe solar filter on the camera. For that location the eclipse was partial. The Moon covered about 90 percent of the Sun’s diameter at maximum, seen near the middle of the eclipse sequence.

(Image: Gary Chan)

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The night sky would present a very different vista if you had X-ray vision (and could tear your eyes away for two seconds from looking at people in their pants). To wit:

X-rays are about 1,000 times more energetic than visible light photons and are produced by violent explosions and high temperature astronomical environments. Instead of the familiar steady stars, the sky would seem to be filled with exotic stars, active galaxies, and hot supernova remnants. The featured X-ray image captures in unprecedented detail the entire sky in X-rays as seen by the eROSITA telescope onboard Spektr-RG satellite, orbiting around the L2 point of the Sun-Earth system, launched last year. The image shows the plane of our Milky Way galaxy across the centre, a diffuse and pervasive X-ray background, the hot interstellar bubble known as the North Polar Spur, sizzling supernova remnants such as Vela, the Cygnus Loop and Cas A, energetic binary stars including Cyg X-1 and Cyg X-2, the LMC galaxy, and the Coma, Virgo, and Fornax clusters of galaxies. This first sky scan by eROSITA located over one million X-ray sources, some of which are not understood and will surely be topics for future research.

(Image: J. Sanders, H. Brunner, A. Merloni & eSASS Team (MPE); E. Churazov, M. Gilfanov, R. Sunyaev (IKI))

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