Skip to main content

Posts

Showing posts from June, 2024
What's happened since the universe started? The time spiral shown here features a few notable highlights . At the spiral's center is the Big Bang , the place where time , as we know it, began about 13.8 billion years ago. Within a few billion years atoms formed , then stars formed from atoms, galaxies formed from stars and gas, our Sun formed, soon followed by our Earth , about 4.6 billion years ago. Life on Earth begins about 3.8 billion years ago, followed by cells , then photosynthesis within a billion years. About 1.7 billion years ago, multicellular life on Earth began to flourish. Fish began to swim about 500 million years ago, and mammals because walking on land about 200 million years ago. Humans first appeared only about 6 million years ago, and made the first cities only about 10,000 years ago. The time spiral illustrated stops there, but human spaceflight might be added, which started only 75 years ago, and useful artificial intelligence began to take h...
About 12 seconds into this video, something unusual happens. The Earth begins to rise. Never seen by humans before, the rise of the Earth over the limb of the Moon occurred about 55.5 years ago and surprised and amazed the crew of Apollo 8 . The crew immediately scrambled to take still images of the stunning vista caused by Apollo 8 's orbit around the Moon. The featured video is a modern reconstruction of the event as it would have looked were it recorded with a modern movie camera. The colorful orb of our Earth stood out as a familiar icon rising above a distant and unfamiliar moonscape , the whole scene the conceptual reverse of a more familiar moonrise as seen from Earth. To many, the scene also spoke about the unity of humanity: that big blue marble -- that's us -- we all live there. The two-minute video is not time-lapse -- this is the real speed of the Earth rising through the windows of Apollo 8 . Seven months and three missions later, Apollo 11 astronauts w...

A Solstice Moon

Rising opposite the setting Sun, June's Full Moon occurred within about 28 hours of the solstice. The Moon stays close to the Sun's path along the ecliptic plane and so while the solstice Sun climbed high in daytime skies, June's Full Moon remained low that night as seen from northern latitudes. In fact, the Full Moon hugs the horizon in this June 21 rooftop night sky view from Bursa, Turkey, constructed from exposures made every 10 minutes between moonrise and moonset. In 2024 the Moon also reached a major lunar standstill , an extreme in the monthly north-south range of moonrise and moonset caused by the precession of the Moon's orbit over an 18.6 year cycle . As a result, this June solstice Full Moon was at its southernmost moonrise and moonset along the horizon . from NASA https://ift.tt/MhdQxAm

Comet 13P Olbers

Not a paradox, Comet 13P/Olbers is returning to the inner Solar System after 68 years. The periodic, Halley-type comet will reach its next perihelion or closest approach to the Sun on June 30 and has become a target for binocular viewing low in planet Earth's northern hemisphere night skies . But this sharp telescopic image of 13P is composed of stacked exposures made on the night of June 25. It easily reveals shifting details in the bright comet's torn and tattered ion tail buffeted by the wind from an active Sun, along with a broad, fanned-out dust tail and slightly greenish coma. The frame spans over two degrees across a background of faint stars toward the constellation Lynx. from NASA https://ift.tt/U5EbQeM

Protostellar Outflows in Serpens

Jets of material blasting from newborn stars, are captured in this James Webb Space Telescope close-up of the Serpens Nebula. The powerful protostellar outflows are bipolar, twin jets spewing in opposite directions. Their directions are perpendicular to accretion disks formed around the spinning, collapsing stellar infants . In the NIRcam image, the reddish color represents emission from molecular hydrogen and carbon monoxide produced as the jets collide with the surrounding gas and dust. The sharp image shows for the first time that individual outflows detected in the Serpens Nebula are generally aligned along the same direction. That result was expected, but has only now come into clear view with Webb's detailed exploration of the active young star-forming region. Brighter foreground stars exhibit Webb's characteristic diffraction spikes . At the Serpens Nebula's estimated distance of 1,300 light-years, this cosmic close-up frame is about 1 light-year across. from...
What's happening in the sky this unusual night? Most striking in the featured 4.5-hour 360-degree panoramic video, perhaps, is the pink and purple aurora . That's because this night, encompassing May 11, was famous for its auroral skies around the world . As the night progresses, auroral bands shimmer , the central band of our Milky Way Galaxy rises, and stars shift as the Earth rotates beneath them. Captured here simultaneously is a rare red band running above the aurora: a SAR arc , seen to change only slightly. The flashing below the horizon is caused by passing cars, while the moving spots in the sky are satellites and airplanes. The featured video was captured from Xinjiang , China with four separate cameras. from NASA https://ift.tt/G18FZUR
What is that strange brown ribbon on the sky? When observing the star cluster NGC 4372 , observers frequently take note of an unusual dark streak nearby running about three degrees in length. The streak, actually a long molecular cloud , has become known as the Dark Doodad Nebula. (Doodad is slang for a thingy or a whatchamacallit. ) Pictured here, the Dark Doodad Nebula sweeps across the center of a rich and colorful starfield. Its dark color comes from a high concentration of interstellar dust that preferentially scatters visible light. The globular star cluster NGC 4372 is visible as the fuzzy white spot on the far left, while the bright blue star gamma Muscae is seen to the cluster's upper right. The Dark Doodad Nebula can be found with strong binoculars toward the southern constellation of the Fly ( Musca ). from NASA https://ift.tt/8Bg0Cbr
What if we could see back to the beginning of the universe? We could see galaxies forming. But what did galaxies look like back then? These questions took a step forward recently with the release of the analysis of a James Webb Space Telescope (JWST) image that included the most distant object yet discovered. Most galaxies formed at about 3 billion years after the Big Bang , but some formed earlier. Pictured in the inset box is JADES - GS-z14-0 , a faint smudge of a galaxy that formed only 300 million years after the universe started . In technical terms, this galaxy lies at the record redshift of z=14.32, and so existed when the universe was only one fiftieth of the its present age. Practically all of the objects in the featured photograph are galaxies. from NASA https://ift.tt/HlNR6gJ
What creates Saturn's colors? The featured picture of Saturn only slightly exaggerates what a human would see if hovering close to the giant ringed world. The image was taken in 2005 by the robot Cassini spacecraft that orbited Saturn from 2004 to 2017. Here Saturn's majestic rings appear directly only as a curved line, appearing brown, in part from its infrared glow. The rings best show their complex structure in the dark shadows they create across the upper part of the planet. The northern hemisphere of Saturn can appear partly blue for the same reason that Earth's skies can appear blue -- molecules in the cloudless portions of both planet's atmospheres are better at scattering blue light than red. When looking deep into Saturn's clouds , however, the natural gold hue of Saturn's clouds becomes dominant. It is not known why southern Saturn does not show the same blue hue -- one hypothesis holds that clouds are higher there. It is also not known wh...

Lynds Dark Nebula 1251

Stars are forming in Lynds Dark Nebula ( LDN ) 1251. About 1,000 light-years away and drifting above the plane of our Milky Way galaxy, LDN 1251 is also less appetizingly known as "The Rotten Fish Nebula." The dusty molecular cloud is part of a complex of dark nebulae mapped toward the Cepheus flare region. Across the spectrum , astronomical explorations of the obscuring interstellar clouds reveal energetic shocks and outflows associated with newborn stars, including the telltale reddish glow from scattered Herbig-Haro objects hiding in the image. Distant background galaxies also lurk in the scene, almost buried behind the dusty expanse. This alluring view spans over four full moons on the sky, or 35 light-years at the estimated distance of LDN 1251. from NASA https://ift.tt/n724tWS

Hubble s NGC 1546

Returning to science operations on June 14, the Hubble Space Telescope used its new pointing mode to capture this sharp image of spiral galaxy NGC 1546 . A member of the Dorado galaxy group , the island universe lies a mere 50 million light-years away. The galactic disk of NGC 1546 is tilted to our line-of-sight, with the yellowish light of the old stars and bluish regions of newly formed stars shining through the galaxy's dust lanes. More distant background galaxies are scattered throughout this Hubble view. Launched in 1990, Hubble has been exploring the cosmos for more than three decades, recently celebrating its 34th anniversary. from NASA https://ift.tt/2iO0EYN

Sandy and the Moon Halo

Last April's Full Moon shines through high clouds near the horizon, casting shadows in this garden-at-night skyscape. Along with canine sentinel Sandy watching the garden gate, the wide-angle snapshot also captured the bright Moon's 22 degree ice halo. But June's bright Full Moon will cast shadows too. This month, the Moon's exact full phase occurs at 01:08 UTC June 22. That's a mere 28 hours or so after today's June solstice (at 20:51 UTC June 20), the moment when the Sun reaches its maximum northern declination. Known to some as a Strawberry Moon, June's Full Moon is at its southernmost declination, and of course will create its own 22 degree halos in hazy night skies. from NASA https://ift.tt/XqbeAz8
Do dragons fight on the altar of the sky? Although it might appear that way, these dragons are illusions made of thin gas and dust. The emission nebula NGC 6188, home to the glowing clouds, is found about 4,000 light years away near the edge of a large molecular cloud, unseen at visible wavelengths, in the southern constellation Ara (the Altar). Massive, young stars of the embedded Ara OB1 association were formed in that region only a few million years ago, sculpting the dark shapes and powering the nebular glow with stellar winds and intense ultraviolet radiation . The recent star formation itself was likely triggered by winds and supernova explosions from previous generations of massive stars , that swept up and compressed the molecular gas. This impressively detailed image spans over 2 degrees (four full Moons), corresponding to over 150 light years at the estimated distance of NGC 6188 . from NASA https://ift.tt/zZYuERf
Yes, but can your thunderstorm do this? Pictured here are gigantic jets shooting up from a thunderstorm last week toward the Himalayan Mountains in China and Bhutan . The composite image captured four long jets that occurred only minutes apart. Gigantic jets , documented only in this century, are a type of lightning discharge that occurs between some thunderstorms and the Earth's ionosphere high above them. They are an unusual type of lightning that is much different from regular cloud-to-cloud and cloud-to-ground lightning . The bottoms of gigantic jets appear similar to a cloud-to-above strike called blue jets , while the tops appear similar to upper-atmosphere red sprites . Although the mechanism and trigger that cause gigantic jets remains a topic of research , it is clear that the jets reduce charge imbalance between different parts of Earth's atmosphere . A good way to look for gigantic jets is to watch a powerful but distant thunderstorm from a clear locatio...
Squids on Earth aren't this big. This mysterious squid-like cosmic cloud spans nearly three full moon s on planet Earth's sky. Discovered in 2011 by French astro-imager Nicolas Outters , the Squid Nebula's bipolar shape is distinguished here by the telltale blue emission from doubly ionized oxygen atoms. Though apparently surrounded by the reddish hydrogen emission region Sh2-129, the true distance and nature of the Squid Nebula have been difficult to determine . Still, one investigation suggests Ou4 really does lie within Sh2-129 some 2,300 light-years away. Consistent with that scenario, the cosmic squid would represent a spectacular outflow of material driven by a triple system of hot, massive stars, cataloged as HR8119 , seen near the center of the nebula. If so, this truly giant squid nebula would physically be over 50 light-year s across. from NASA https://ift.tt/Z6dGj72
What happens if a star gets too close to a black hole? The black hole can rip it apart -- but how? It's not the high gravitational attraction itself that's the problem -- it's the difference in gravitational pull across the star that creates the destruction. In the featured animated video illustrating this disintegration, you first see a star approaching the black hole. Increasing in orbital speed, the star's outer atmosphere is ripped away during closest approach. Much of the star's atmosphere disperses into deep space, but some continues to orbit the black hole and forms an accretion disk . The animation then takes you into the accretion disk while looking toward the black hole. Including the strange visual effects of gravitational lensing , you can even see the far side of the disk . Finally, you look along one of the jet s being expelled along the spin axis. Theoretical models indicate that these jets not only expel energetic gas, but also create energe...

Prominences and Filaments on the Active Sun

This colorized and sharpened image of the Sun is composed of frames recording emission from hydrogen atoms in the solar chromosphere on May 15. Approaching the maximum of solar cycle 25 , a multitude of active regions and twisting, snake-like solar filaments are seen to sprawl across the surface of the active Sun. Suspend in the active regions' strong magnetic fields, the filaments of plasma lofted above the Sun's edge appear as bright solar prominences. The large prominences seen near 4 o'clock, and just before 9 o'clock around the solar limb are post flare loops from two powerful X-class solar flares that both occurred on that day . In fact, the 4 o'clock prominence is associated with the monster active region AR 3664 just rotating off the Sun's edge. from NASA https://ift.tt/5a3FGH6

RCW 85

From the 1960 astronomical catalog of Rodgers, Campbell and Whiteoak , emission region RCW 85 shines in southern night skies between bright stars Alpha and Beta Centauri. About 5,000 light years distant, the hazy interstellar cloud of glowing hydrogen gas and dust is faint. But detailed structures along well-defined rims within RCW 85 are traced in this cosmic skyscape composed of 28 hours of narrow and broadband exposures. Suggestive of dramatic shapes in other stellar nurseries where natal clouds of gas and dust are sculpted by energetic winds and radiation from newborn stars, the tantalizing nebula has been called the Devil's Tower. This telescopic frame would span around 100 light-years at the estimated distance of RCW 85 . from NASA https://ift.tt/MvhUDqT

Messier 66 Close Up

Big, beautiful spiral galaxy Messier 66 lies a mere 35 million light-years away. The gorgeous island universe is about 100 thousand light-years across, similar in size to the Milky Way. This Hubble Space Telescope close-up view spans a region about 30,000 light-years wide around the galactic core. It shows the galaxy's disk dramatically inclined to our line-of-sight. Surrounding its bright core, the likely home of a supermassive black hole, obscuring dust lanes and young, blue star clusters sweep along spiral arms dotted with the tell-tale glow of pinkish star forming regions. Messier 66, also known as NGC 3627, is the brightest of the three galaxies in the gravitationally interacting Leo Triplet . from NASA https://ift.tt/Sp7RNj6
It was the first time ever. At least, the first time this photographer had ever seen aurora from his home mountains. And what a spectacular aurora it was. The Karkonosze Mountains in Poland are usually too far south to see any auroras. But on the amazing night of May 10 - 11, purple and green colors lit up much of the night sky, a surprising spectacle that also appeared over many mid- latitude locations around the Earth . The featured image is a composite of six vertical exposures taken during the auroral peak. The futuristic buildings on the right are part of a meteorological observatory located on the highest peak of the Karkonosze Mountains . The purple color is primarily due to Sun-triggered , high-energy electrons impacting nitrogen molecules in Earth's atmosphere . Our Sun is reaching its maximum surface activity over the next two years, and although many more auroras are predicted, most will occur over regions closer to the Earth's poles . from NASA http...
Why is the sky near Antares and Rho Ophiuchi so colorful, yet dusty? The colors result from a mixture of objects and processes. Fine dust -- illuminated by starlight -- produces blue reflection nebulae . Gaseous clouds whose atoms are excited by ultraviolet starlight produce reddish emission nebulae . Backlit dust clouds block starlight and so appear dark . Antares , a red supergiant and one of the brighter stars in the night sky , lights up the yellow-red clouds on the upper right of the featured image. The Rho Ophiuchi star system lies at the center of the blue reflection nebula on the left, while a different reflection nebula, IC 4605 , lies just below and right of the image center. These star clouds are even more colorful than humans can see, emitting light across the electromagnetic spectrum . from NASA https://ift.tt/fdIYn7J
Is the Lion Nebula the real ruler of the constellation Cepheus ? This powerful feline appearing nebula is powered by two massive stars , each with a mass over 20 times greater than our Sun . Formed from shells of ionized gas that have expanded, the nebula's energetic matter not only glows , but is dense enough to contract gravitationally and form stars . The angular size of the Lion Nebula, officially named Sh 2-132, is slightly greater than that of the full moon . The gaseous iconic region resides about 10,000 light year s away in a constellation named after the King of Aethopia in Greek mythology . from NASA https://ift.tt/AnNz1QM
What is that light in the sky? The answer to one of humanity's more common questions may emerge from a few quick observations. For example -- is it moving or blinking? If so, and if you live near a city , the answer is typically an airplane, since planes are so numerous and so few stars and satellites are bright enough to be seen over the glare of artificial city lights . If not, and if you live far from a city, that bright light is likely a planet such as Venus or Mars -- the former of which is constrained to appear near the horizon just before dawn or after dusk. Sometimes the low apparent motion of a distant airplane near the horizon makes it hard to tell from a bright planet , but even this can usually be discerned by the plane's motion over a few minutes. Still unsure? The featured chart gives a sometimes-humorous but mostly-accurate assessment. Dedicated sky enthusiasts will likely note -- and are encouraged to provide -- polite corrections. from NASA https://if...

Pandora's Cluster of Galaxies

This deep field mosaicked image presents a stunning view of galaxy cluster Abell 2744 recorded by the James Webb Space Telescope's NIRCam. Also dubbed Pandora's Cluster, Abell 2744 itself appears to be a ponderous merger of three different massive galaxy clusters. It lies some 3.5 billion light-years away, toward the constellation Sculptor. Dominated by dark matter , the mega-cluster warps and distorts the fabric of spacetime, gravitationally lensing even more distant objects. Redder than the Pandora cluster galaxies many of the lensed sources are very distant galaxies in the early Universe, their lensed images stretched and distorted into arcs. Of course distinctive diffraction spikes mark foreground Milky Way stars. At the Pandora Cluster's estimated distance this cosmic box spans about 6 million light-years. But don't panic. You can explore the tantalizing region in a 2 minute video tour . from NASA https://ift.tt/tzHI7Dw

Sharpless 308: The Dolphin Head Nebula

Blown by fast winds from a hot, massive star, this cosmic bubble is huge. Cataloged as Sharpless 2-308 it lies some 5,000 light-years away toward the well-trained constellation Canis Major and covers slightly more of the sky than a Full Moon. That corresponds to a diameter of 60 light-years at its estimated distance. The massive star that created the bubble, a Wolf-Rayet star , is the bright one near the center of the nebula. Wolf-Rayet stars have over 20 times the mass of the Sun and are thought to be in a brief, pre-supernova phase of massive star evolution. Fast winds from this Wolf-Rayet star create the bubble-shaped nebula as they sweep up slower moving material from an earlier phase of evolution. The windblown nebula has an age of about 70,000 years. Relatively faint emission captured by narrowband filters in the deep image is dominated by the glow of ionized oxygen atoms mapped to a blue hue. Presenting a mostly harmless outline, SH2-308 is also known as The Dolphin-...

NGC 4565: Galaxy on Edge

Magnificent spiral galaxy NGC 4565 is viewed edge-on from planet Earth. Also known as the Needle Galaxy for its narrow profile, bright NGC 4565 is a stop on many telescopic tours of the northern sky, in the faint but well-groomed constellation Coma Berenices . This sharp, colorful image reveals the galaxy's boxy, bulging central core cut by obscuring dust lanes that lace NGC 4565's thin galactic plane. NGC 4565 itself lies about 40 million light-years distant and spans some 100,000 light-years. Easily spotted with small telescopes, sky enthusiasts consider NGC 4565 to be a prominent celestial masterpiece Messier missed . from NASA https://ift.tt/UW3xdNP
What if you saw your shadow on Mars and it wasn't human? Then you might be the Perseverance rover exploring Mars . Perseverance has been examining the Red Planet since 2021, finding evidence of its complex history of volcanism and ancient flowing water , and sending breathtaking images across the inner Solar System . Pictured here in February of 2024, Perseverance looks opposite the Sun and across Neretva Vallis in Jezero Crater , with a local hill visible at the top of the frame. The distinctively non-human shadow of the car-sized rover is visible below center, superposed on scattered rocks . Perseverance, now working without its flying companion Ingenuity , continues to search Mars for signs of ancient life . from NASA https://ift.tt/bG2r7Zk
Why does Comet Pons-Brooks now have tails pointing in opposite directions? The most spectacular tail is the blue-glowing ion tail that is visible flowing down the image. The ion tail is pushed directly out from the Sun by the solar wind . On the upper right is the glowing central coma of Comet 12P/Pons–Brooks . Fanning out from the coma , mostly to the left, is the comet's dust tail . Pushed out and slowed down by the pressure of sunlight , the dust tail tends to trail the comet along its orbit and, from some viewing angles , can appear opposite to the ion tail. The distant, bright star Alpha Leporis is seen at the bottom of the featured image captured last week from Namibia . Two days ago, the comet passed its closest to the Earth and is now best visible from southern skies as it dims and glides back to the outer Solar System . from NASA https://ift.tt/Q4ajXZm

NGC 2403 in Camelopardalis

Magnificent island universe NGC 2403 stands within the boundaries of the long-necked constellation Camelopardalis . Some 10 million light-years distant and about 50,000 light-years across, the spiral galaxy also seems to have more than its fair share of giant star forming HII regions , marked by the telltale reddish glow of atomic hydrogen gas. The giant HII regions are energized by clusters of hot, massive stars that explode as bright supernovae at the end of their short and furious lives. A member of the M81 group of galaxies, NGC 2403 closely resembles a galaxy in our own local galaxy group with an abundance of star forming regions, M33, the Triangulum Galaxy . Spiky in appearance, bright stars in this portrait of NGC 2403 are in the foreground, within our own Milky Way. Also in the foreground of the deep, wide-field, telescopic image are the Milky Way's dim and dusty interstellar clouds also known as galactic cirrus or integrated flux nebulae. But faint features that seem...
No one, presently, sees the Moon rotate like this. That's because the Earth's moon is tidally locked to the Earth, showing us only one side . Given modern digital technology , however, combined with many detailed images returned by the Lunar Reconnaissance Orbiter (LRO), a high resolution virtual Moon rotation movie has been composed. The featured time-lapse video starts with the standard Earth view of the Moon . Quickly, though, Mare Orientale , a large crater with a dark center that is difficult to see from the Earth, rotates into view just below the equator. From an entire lunar month condensed into 24 seconds, the video clearly shows that the Earth side of the Moon contains an abundance of dark lunar maria , while the lunar far side is dominated by bright lunar highlands . Currently, over 32 new missions to the Moon are under active development from multiple countries and companies, including NASA's Artemis program which aims to land people on the Moon again wi...