APOD Wrote:Explanation: Where did the gold in your jewelry originate? No one is completely sure. The relative average abundance in our Solar System appears higher than can be made in the early universe, in stars, and even in typical supernova explosions. Some astronomers have suggested, and many believe, that neutron-rich heavy elements such as gold might be most easily made in rare neutron-rich explosions such as the collision of neutron stars. Pictured here is an artist's illustration depicting two neutron stars spiraling in toward each other, just before they collide. Since neutron star collisions are also suggested as the origin of short duration gamma-ray bursts, it is possible that you already own a souvenir from one of the most powerful explosions in the universe.

Quote:This illustration shows the hot, dense, expanding cloud of debris stripped from two neutron stars just before they collided. Within this neutron-rich debris, large quantities of some of the universe's heaviest elements were forged, including hundreds of Earth masses of gold and platinum.

This represents the first time scientists detected light tied to a gravitational-wave event, thanks to two merging neutron stars in the galaxy NGC 4993, located about 130 million light-years from Earth in the constellation Hydra. Learn more about this phenomenon.

Quote:This NASA/ESA Hubble Space Telescope image is chock-full of galaxies. Each glowing speck is a different galaxy, except the bright flash in the middle of the image which is actually a star lying within our own galaxy that just happened to be in the way. At the center of the image lies something especially interesting, the center of the massive galaxy cluster called WHL J24.3324-8.477, including the brightest galaxy of the cluster.

The Universe contains structures on various scales — planets collect around stars, stars collect into galaxies, galaxies collect into groups, and galaxy groups collect into clusters. Galaxy clusters contain hundreds to thousands of galaxies bound together by gravity. Dark matter and dark energy play key roles in the formation and evolution of these clusters, so studying massive galaxy clusters can help scientists to unravel the mysteries of these elusive phenomena

Quote:NASA's Solar Dynamics Observatory came across an oddity that the spacecraft has rarely observed before: a dark filament encircling an active region (Oct. 29-31, 2017). Solar filaments are clouds of charged particles that float above the sun, tethered to it by magnetic forces. They are usually elongated and uneven strands. Only a handful of times before have we seen one shaped like a circle. The black area to the left of the brighter active region is a coronal hole, a magnetically open region of the sun. While it may have no major scientific value, it is noteworthy because of its rarity.

Quote:A broad hole in the corona was the Sun's dominant feature November 7-9, 2017, as shown in this image from NASA's Solar Dynamics Observatory. The hole is easily recognizable as the dark expanse across the top of the Sun and extending down in each side. Coronal holes are magnetically open areas on the Sun that allow high-speed solar wind to gush out into space. They always appear darker in extreme ultraviolet. This one was likely the source of bright aurora that shimmered for numerous observers, with some reaching down even to Nebraska.

Quote:This picturesque view from the NASA/ESA Hubble Space Telescope peers into the distant universe to reveal a galaxy cluster called Abell 2537.

Galaxy clusters such as this one contain thousands of galaxies of all ages, shapes and sizes, together totaling a mass thousands of times greater than that of the Milky Way. These groupings of galaxies are colossal — they are the largest structures in the Universe to be held together by their own gravity.

Clusters are useful in probing mysterious cosmic phenomena like dark energy and dark matter, which can contort space itself. There is so much matter stuffed into a cluster like Abell 2537 that its gravity has visible effects on its surroundings. Abell 2537’s gravity warps the very structure of its environment (spacetime), causing light to travel along distorted paths through space. This phenomenon can produce a magnifying effect, allowing us to see faint objects that lie far behind the cluster and are thus otherwise unobservable from Earth. Abell 2537 is a particularly efficient lens, as demonstrated by the stretched stripes and streaking arcs visible in the frame. These smeared shapes are in fact galaxies, their light heavily distorted by the gravitational field of Abell 2537.

APOD Wrote:Explanation: Have you ever watched the Moon rise? The slow rise of a nearly full moon over a clear horizon can be an impressive sight. One impressive moonrise was imaged in early 2013 over Mount Victoria Lookout in Wellington, New Zealand. With detailed planning, an industrious astrophotographer placed a camera about two kilometers away and pointed it across the lookout to where the Moon would surely soon be making its nightly debut. The featured single shot sequence is unedited and shown in real time -- it is not a time lapse. People on Mount Victoria Lookout can be seen in silhouette themselves admiring the dawn of Earth's largest satellite. Seeing a moonrise yourself is not difficult: it happens every day, although only half the time at night. Each day the Moon rises about fifty minutes later than the previous day, with a full moon always rising at sunset. A good time to see a full moonrise will occur tonight at sunset as the Moon's relative closeness to Earth during a full phase -- called a supermoon -- will cause it to appear slightly larger and brighter than usual.

APOD Wrote:Explanation: To some, it may look like a beehive harboring an evil bee. In reality, the featured Hubble image captures a cosmic pillar of dust, two-light years long, inside of which is Herbig-Haro 666 -- a young star emitting powerful jets. The structure lies within one of our galaxy's largest star forming regions, the Carina Nebula, shining in southern skies at a distance of about 7,500 light-years. The pillar's layered outline are shaped by the winds and radiation of Carina's young, hot, massive stars, some of which are still forming inside the nebula. A dust-penetrating view in infrared light better shows the two, narrow, energetic jets blasting outward from a still hidden infant star.

Quote:Images such as this also show the hints of conflict. In Syria, darkness now reigns along a 300-kilometer stretch where lights use to line the Euphrates River in the east of the country. This has left most of eastern Syria in the dark.

NASA Wrote:Where do most of the elements essential for life on Earth come from? The answer: inside the furnaces of stars and the explosions that mark the end of some stars’ lives.

Astronomers have long studied exploded stars and their remains – known as “supernova remnants” – to better understand exactly how stars produce and then disseminate many of the elements observed on Earth, and in the cosmos at large.

Due to its unique evolutionary status, Cassiopeia A (Cas A) is one of the most intensely studied of these supernova remnants. A new image from NASA’s Chandra X-ray Observatory shows the location of different elements in the remains of the explosion: silicon (red), sulfur (yellow), calcium (green) and iron (purple). Each of these elements produces X-rays within narrow energy ranges, allowing maps of their location to be created. The blast wave from the explosion is seen as the blue outer ring.

NASA Wrote:OSIRIS-REx took a look back at home while making its way toward the asteroid Bennu.

APOD Wrote:Explanation: What are those red clouds surrounding the Andromeda galaxy? This galaxy, M31, is often imaged by planet Earth-based astronomers. As the nearest large spiral galaxy, it is a familiar sight with dark dust lanes, bright yellowish core, and spiral arms traced by clouds of bright blue stars. A mosaic of well-exposed broad and narrow-band image data, this colorful portrait of our neighboring island universe offers strikingly unfamiliar features though, faint reddish clouds of glowing ionized hydrogen gas in the same wide field of view. These ionized hydrogen clouds surely lie in the foreground of the scene, well within our Milky Way Galaxy. They are likely associated with the pervasive, dusty interstellar cirrus clouds scattered hundreds of light-years above our own galactic plane.

APOD Wrote:Explanation: This exciting and unfamiliar view of the Orion Nebula is a visualization based on astronomical data and movie rendering techniques. Up close and personal with a famous stellar nursery normally seen from 1,500 light-years away, the digitally modeled frame transitions from a visible light representation based on Hubble data on the left to infrared data from the Spitzer Space Telescope on the right. The perspective at the center looks along a valley over a light-year wide, in the wall of the region's giant molecular cloud. Orion's valley ends in a cavity carved by the energetic winds and radiation of the massive central stars of the Trapezium star cluster. The single frame is part of a multiwavelength, three-dimensional video that lets the viewer experience an immersive, three minute flight through the Great Nebula of Orion.

APOD Wrote:Explanation: Also known as the Moon's "ashen glow" or the "Old Moon in the New Moon's arms", earthshine is earthlight reflected from the Moon's night side. This stunning image of earthshine from a young crescent moon was taken from Las Campanas Observatory, Atacama Desert, Chile, planet Earth near moonset on January 18. Dramatic atmospheric inversion layers appear above the Pacific Ocean, colored by the sunset at the planet's western horizon. But the view from the Moon would have been stunning, too. When the Moon appears in Earth's sky as a slender crescent, a dazzlingly bright, nearly full Earth would be seen from the lunar surface. A description of earthshine, in terms of sunlight reflected by Earth's oceans in turn illuminating the Moon's dark surface, was written 500 years ago by Leonardo da Vinci.

(07-23-2013, 08:35 PM)Jeremy Wrote: It'd be even more beautiful if that's what it really looked like but sadly those are all false color images

APOD Wrote:Explanation: What if you could look out from the center of our Galaxy -- what might you see? Two scientifically-determined possibilities are shown in the featured video, an immersive 360-degree view which allows you to look around in every direction. The pictured computer simulation is based on infrared data from ESO's Very Large Telescope in Chile and X-ray data from NASA's orbiting Chandra X-ray Observatory. As the video starts, you quickly approach Sgr A*, the supermassive black hole in the Galactic center. Then looking out, this 500-year time-lapse simulation shows glowing gas and many points of light orbiting all around you. Many of these points are young Wolf-Rayet stars that have visible hot winds blowing out into surrounding nebulas. Clouds approaching close become elongated, while objects approaching too close fall in. Toward the video's end the simulation repeats, but this time with the dynamic region surrounding Sgr A* expelling hot gas that pushes back against approaching material.