Friday, June 15, 2018

Criminals Who Hate by Unknown Author


By Unknown Author

To the Editor: Re Clyde Haberman’s ”Finding Flaws in the Logic of Bias Laws” (NYC column, March 12): Unlike hate crimes, the four recent slashings in the New York City subways are random, senseless and purposeless acts of violence. No one is …

Published: March 14, 1999 at 07:00PM

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Thursday, February 22, 2018

When Roses Aren t Red


Not all roses are red of course, but they can still be very pretty. Likewise, the beautiful Rosette Nebula and other star forming regions are often shown in astronomical images with a predominately red hue, in part because the dominant emission in the nebula is from hydrogen atoms. Hydrogen's strongest optical emission line, known as H-alpha, is in the red region of the spectrum, but the beauty of an emission nebula need not be appreciated in red light alone. Other atoms in the nebula are also excited by energetic starlight and produce narrow emission lines as well. In this gorgeous view of the Rosette Nebula, narrowband images are combined to show emission from sulfur atoms in red, hydrogen in blue, and oxygen in green. In fact, the scheme of mapping these narrow atomic emission lines into broader colors is adopted in many Hubble images of stellar nurseries. The image spans about 100 light-years in the constellation Monoceros, at the 3,000 light-year estimated distance of the Rosette Nebula. To make the Rosette red, just follow this link or slide your cursor over the image. via NASA http://ift.tt/2EV0eoC

Wednesday, February 21, 2018

Jupiter in Infrared from Hubble


Jupiter looks a bit different in infrared light. To better understand Jupiter's cloud motions and to help NASA's robotic Juno spacecraft understand the Hubble Space Telescope is being directed to regularly image the entire Jovian giant. The colors of Jupiter being monitored go beyond the normal human visual range to include both ultraviolet and infrared light. Featured here in 2016, three bands of near-infrared light have been digitally reassigned into a mapped color image. Jupiter appears different in infrared partly because the amount of sunlight reflected back is distinct, giving differing cloud heights and latitudes discrepant brightnesess. Nevertheless, many familiar features on Jupiter remain, including the light zones and dark belts that circle the planet near the equator, the Great Red Spot on the lower left, and the string-of-pearls storm systems south of the Great Red Spot. The poles glow because high altitute haze there is energized by charged particles from Jupiter's magnetosphere. Juno has now completed 10 of 12 planned science orbits of Jupiter and continues to record data that are helping humanity to understand not only Jupiter's weather but what lies beneath Jupiter's thick clouds. via NASA http://ift.tt/2oku2kg

Tuesday, February 20, 2018

A Partial Solar Eclipse over Buenos Aires


What's happened to top of the Sun? Last week, parts of Earth's southern hemisphere were treated to a partial solar eclipse, where the Moon blocks out part of the Sun. The featured image was taken toward the end of the eclipse from the coast of Uruguay overlooking Argentina's Buenos Aires. Light-house adorned Farallón Island is seen in the foreground, and a plane is visible just to the left of the Sun. The image is actually a digital combination of two consecutive exposures taken with the same camera using the same settings -- one taken of the landscape and another of the background Sun. The next solar eclipse visible on Earth will be another partial eclipse occurring in mid-July and visible from parts of southern Australia including Tasmania. via NASA http://ift.tt/2C73dJH

Sunday, February 18, 2018

Galaxy Formation in a Magnetic Universe


How did we get here? We know that we live on a planet orbiting a star orbiting a galaxy, but how did all of this form? To understand details better, astrophysicists upgraded the famous Illustris Simulation into IllustrisTNG -- now the most sophisticated computer model of how galaxies evolved in our universe. Specifically, this featured video tracks magnetic fields from the early universe (redshift 5) until today (redshift 0). Here blue represents relatively weak magnetic fields, while white depicts strong. These B fields are closely matched with galaxies and galaxy clusters. As the simulation begins, a virtual camera circles the virtual IllustrisTNG universe showing a young region -- 30-million light years across -- to be quite filamentary. Gravity causes galaxies to form and merge as the universe expands and evolves. At the end, the simulated IllustrisTNG universe is a good statistical match to our present real universe, although some interesting differences arise -- for example a discrepancy involving the power in radio waves emitted by rapidly moving charged particles. via NASA http://ift.tt/2CuxNZz

Saturday, February 17, 2018

LL Ori and the Orion Nebula


Stars can make waves in the Orion Nebula's sea of gas and dust. This esthetic close-up of cosmic clouds and stellar winds features LL Orionis, interacting with the Orion Nebula flow. Adrift in Orion's stellar nursery and still in its formative years, variable star LL Orionis produces a wind more energetic than the wind from our own middle-aged Sun. As the fast stellar wind runs into slow moving gas a shock front is formed, analogous to the bow wave of a boat moving through water or a plane traveling at supersonic speed. The small, arcing, graceful structure just above and left of center is LL Ori's cosmic bow shock, measuring about half a light-year across. The slower gas is flowing away from the Orion Nebula's hot central star cluster, the Trapezium, located off the upper left corner of the picture. In three dimensions, LL Ori's wrap-around shock front is shaped like a bowl that appears brightest when viewed along the "bottom" edge. This beautiful painting-like photograph is part of a large mosaic view of the complex stellar nursery in Orion, filled with a myriad of fluid shapes associated with star formation. via NASA http://ift.tt/2F9mp8d

Sunday, February 11, 2018

A Partial Eclipse Over Manila Bay


What's happened to the setting Sun? An eclipse! In early 2009, the Moon eclipsed part of the Sun as visible from parts of Africa, Australia, and Asia. In particular the featured image, taken from the Mall of Asia seawall, caught a partially eclipsed Sun setting over Manila Bay in the Philippines. Piers are visible in silhouette in the foreground. Eclipse chasers and well placed sky enthusiasts captured many other interesting and artistic images of the year's only annular solar eclipse, including movies, eclipse shadow arrays, and rings of fire. On Thursday parts of the Sun again will become briefly blocked by the Moon, again visible to some as a partial eclipse of the Sun. Thursday's eclipse, however, will only be visible from parts of southern South America and Antarctica. via NASA http://ift.tt/2Ei6EKV

Saturday, February 10, 2018

Roadster, Starman, Planet Earth


Don't panic. It's just a spacesuited mannequin named Starman. As the sunlit crescent of planet Earth recedes in the background, Starman is comfortably seated at the wheel of a Tesla Roadster in this final image of the payload launched by a Falcon Heavy rocket on February 6. Internationally designated 2018-017A, roadster and Starman are headed for space beyond the orbit of Mars. The successful Falcon Heavy rocket has now become the most powerful rocket in operation and the roadster one of four electric cars launched from planet Earth. The other three were launched to the Moon by historically more powerful (but not reusable) Saturn V rockets. Still, Starman's roadster is probably the only one that would be considered street legal. via NASA http://ift.tt/2C9n06N

Friday, February 9, 2018

Total Solar Lunar Eclipse


This digitally processed and composited picture creatively compares two famous eclipses in one; the total lunar eclipse (left) of January 31, and the total solar eclipse of August 21, 2017. The Moon appears near mid-totality in both the back-to-back total eclipses. In the lunar eclipse, its surface remains faintly illuminated in Earth's dark reddened shadow. But in the solar eclipse the Moon is in silhouette against the Sun's bright disk, where the otherwise dark lunar surface is just visible due to earthshine. Also seen in the lunar-aligned image pair are faint stars in the night sky surrounding the eclipsed Moon. Stunning details of prominences and coronal streamers surround the eclipsed Sun. The total phase of the Great American Eclipse of August 21 lasted about 2 minutes or less for locations along the Moon's shadow path. From planet Earth's night side, totality for the Super Blue Blood Moon of January 31 lasted well over an hour. via NASA http://ift.tt/2H0ceDv

Wednesday, February 7, 2018

NGC 7331 Close Up


Big, beautiful spiral galaxy NGC 7331 is often touted as an analog to our own Milky Way. About 50 million light-years distant in the northern constellation Pegasus, NGC 7331 was recognized early on as a spiral nebula and is actually one of the brighter galaxies not included in Charles Messier's famous 18th century catalog. Since the galaxy's disk is inclined to our line-of-sight, long telescopic exposures often result in an image that evokes a strong sense of depth. In this Hubble Space Telescope close-up, the galaxy's magnificent spiral arms feature dark obscuring dust lanes, bright bluish clusters of massive young stars, and the telltale reddish glow of active star forming regions. The bright yellowish central regions harbor populations of older, cooler stars. Like the Milky Way, a supermassive black hole lies at the core of of spiral galaxy NGC 7331. via NASA http://ift.tt/2nSqeqm

Tuesday, February 6, 2018

Galaxy NGC 474: Shells and Star Streams


What's happening to galaxy NGC 474? The multiple layers of emission appear strangely complex and unexpected given the relatively featureless appearance of the elliptical galaxy in less deep images. The cause of the shells is currently unknown, but possibly tidal tails related to debris left over from absorbing numerous small galaxies in the past billion years. Alternatively the shells may be like ripples in a pond, where the ongoing collision with the spiral galaxy just above NGC 474 is causing density waves to ripple through the galactic giant. Regardless of the actual cause, the featured image dramatically highlights the increasing consensus that at least some elliptical galaxies have formed in the recent past, and that the outer halos of most large galaxies are not really smooth but have complexities induced by frequent interactions with -- and accretions of -- smaller nearby galaxies. The halo of our own Milky Way Galaxy is one example of such unexpected complexity. NGC 474 spans about 250,000 light years and lies about 100 million light years distant toward the constellation of the Fish (Pisces). via NASA http://ift.tt/2E2NEQx

Sunday, February 4, 2018

Venus and the Triply Ultraviolet Sun


An unusual type of solar eclipse occurred in 2012. Usually it is the Earth's Moon that eclipses the Sun. That year, most unusually, the planet Venus took a turn. Like a solar eclipse by the Moon, the phase of Venus became a continually thinner crescent as Venus became increasingly better aligned with the Sun. Eventually the alignment became perfect and the phase of Venus dropped to zero. The dark spot of Venus crossed our parent star. The situation could technically be labeled a Venusian annular eclipse with an extraordinarily large ring of fire. Pictured here during the occultation, the Sun was imaged in three colors of ultraviolet light by the Earth-orbiting Solar Dynamics Observatory, with the dark region toward the right corresponding to a coronal hole. Hours later, as Venus continued in its orbit, a slight crescent phase appeared again. The next Venusian transit across the Sun will occur in 2117. via NASA http://ift.tt/2s6x54v

Saturday, February 3, 2018

Earthshadow and the Beehive


The Earth's dark umbral shadow is shaped like a cone extending into space. Of course its circular cross section at the distance of the Moon is more easily seen during a lunar eclipse. In fact, in this composite telephoto image from Earth's night side on January 31, the Earth's shadow has taken on a reddish tinge. The extent of the shadow along the lunar orbit is illustrated by aligning three frames taken just before the start, near the middle of, and just after the end of the total eclipse phase that lasted about 76 minutes. At the upper right and more easily seen during the eclipse's darker total phase is M44, one of the closest large star clusters. A mere 600 light-years away, M44 is also known as the Praesepe or the Beehive Cluster. via NASA http://ift.tt/2BRYrLl

Friday, February 2, 2018

Moonrise Eclipse


This atmospheric picture of a distant horizon looks toward the tall Trisul peaks of India's snowy Himalayan mountains. Taken from a remote location on January 31, brightest star Sirius shines at the upper right. The red Moon rising is gliding through Earth's shadow during the evening's much anticipated total lunar eclipse. Enjoyed across the planet's night side, the eclipse was the first of two total lunar eclipses in 2018, kicking off a good year for moonwatchers. But this was a rare treat. The eclipsed Moon also loomed large near perigee, the closest point in its orbit, during the second Full Moon of the month, also known as a Blue Moon. For the July 27, 2018 total lunar eclipse, the Full Moon will be very near apogee. via NASA http://ift.tt/2EaQqqp

Wednesday, January 31, 2018

The First Explorer


Sixty years ago, on January 31, 1958, the First Explorer was successfully launched by the Army Ballistic Missile Agency on a Jupiter-C rocket. Inaugurating the era of space exploration for the United States, Explorer I was a thirty pound satellite that carried instruments to measure temperatures, and micrometeorite impacts, along with an experiment designed by James A. Van Allen to measure the density of electrons and ions in space. The measurements made by Van Allen's experiment led to an unexpected and then startling discovery of two earth-encircling belts of high energy electrons and ions trapped in the magnetosphere. Now known as the Van Allen Radiation belts, the regions are located in the inner magnetosphere, beyond low Earth orbit. Explorer I ceased transmitting on February 28, 1958, but remained in orbit until March of 1970. via NASA http://ift.tt/2Gxjab3

Tuesday, January 30, 2018

Venus at Night in Infrared from Akatsuki


Why is Venus so different from Earth? To help find out, Japan launched the robotic Akatsuki spacecraft which entered orbit around Venus late in 2015 after an unplanned five-year adventure around the inner Solar System. Even though Akatsuki was past its original planned lifetime, the spacecraft and instruments were operating so well that much of its original mission was reinstated. Also known as the Venus Climate Orbiter, Akatsuki's instruments investigated unknowns about Earth's sister planet, including whether volcanoes are still active, whether lightning occurs in the dense atmosphere, and why wind speeds greatly exceed the planet's rotation speed. In the featured image taken by Akatsuki's IR2 camera, Venus's night side shows a jagged-edged equatorial band of high dark clouds absorbing infrared light from hotter layers deeper in Venus' atmosphere. The bright orange and black stripe on the upper right is a false digital artifact that covers part of the much brighter day side of Venus. Analyses of Akatsuki images and data has shown that Venus has equatorial jet similar to Earth's jet stream. via NASA http://ift.tt/2DKlFVr

Sunday, January 28, 2018

The Spider and The Fly


Will the spider ever catch the fly? Not if both are large emission nebulas toward the constellation of the Charioteer (Auriga). The spider-shaped gas cloud on the left is actually an emission nebula labelled IC 417, while the smaller fly-shaped cloud on the right is dubbed NGC 1931 and is both an emission nebula and a reflection nebula. About 10,000 light-years distant, both nebulas harbor young, open star clusters. For scale, the more compact NGC 1931 (Fly) is about 10 light-years across. via NASA http://ift.tt/2DHUQS2

Friday, January 26, 2018

Selfie at Vera Rubin Ridge


On sol 1943 of its journey of exploration across the surface of Mars, the Curiosity Rover recorded this selfie at the south rim of Vera Rubin Ridge. Of course a sol is a Martian solar day, about 40 minutes longer than an Earth day. Curiosity's sol 1943 corresponds to Earth date January 23, 2018. Also composed as an interactive 360 degree VR, the mosaicked panorama combines 61 exposures taken by the car-sized rover's Mars Hand Lens Imager (MAHLI). Frames containing the imager's arm have been edited out while the extended background used was taken by the rover's Mastcam on sol 1903. At the top of the rover's mast, sitting above the Mastcam, the laser-firing ChemCam housing blocks out the distant peak of Mount Sharp. via NASA http://ift.tt/2EbPy23

Thursday, January 25, 2018

Cartwheel of Fortune


By chance, a collision of two galaxies has created a surprisingly recognizable shape on a cosmic scale, The Cartwheel Galaxy. The Cartwheel is part of a group of galaxies about 500 million light years away in the constellation Sculptor. Two smaller galaxies in the group are visible on the right. The Cartwheel Galaxy's rim is an immense ring-like structure 150,000 light years in diameter composed of newly formed, extremely bright, massive stars. When galaxies collide they pass through each other, their individual stars rarely coming into contact. Still, the galaxies' gravitational fields are seriously distorted by the collision. In fact, the ring-like shape is the result of the gravitational disruption caused by a small intruder galaxy passing through a large one, compressing the interstellar gas and dust and causing a a star formation wave to move out from the impact point like a ripple across the surface of a pond. In this case the large galaxy may have originally been a spiral, not unlike our own Milky Way, transformed into the wheel shape by the collision. But ... what happened to the small intruder galaxy? via NASA http://ift.tt/2DB4lGF

Tuesday, January 23, 2018

Ribbons and Pearls of Spiral Galaxy NGC 1398


Why do some spiral galaxies have a ring around the center? Spiral galaxy NGC 1398 not only has a ring of pearly stars, gas and dust around its center, but a bar of stars and gas across its center, and spiral arms that appear like ribbons farther out. The featured image was taken with ESO's Very Large Telescope at the Paranal Observatory in Chile and resolves this grand spiral in impressive detail. NGC 1398 lies about 65 million light years distant, meaning the light we see today left this galaxy when dinosaurs were disappearing from the Earth. The photogenic galaxy is visible with a small telescope toward the constellation of the Furnace (Fornax). The ring near the center is likely an expanding density wave of star formation, caused either by a gravitational encounter with another galaxy, or by the galaxy's own gravitational asymmetries. via NASA http://ift.tt/2G3GXiy

Sunday, January 21, 2018

An Immersive Visualization of the Galactic Center


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. via NASA http://ift.tt/2BhIheh

Saturday, January 20, 2018

The Upper Michigan Blizzard of 1938


Yes, but can your blizzard do this? In Upper Michigan's Storm of the Century in 1938, some snow drifts reached the level of utility poles. Nearly a meter of new and unexpected snow fell over two days in a storm that started 80 years ago this week. As snow fell and gale-force winds piled snow to surreal heights; many roads became not only impassable but unplowable; people became stranded; cars, school buses and a train became mired; and even a dangerous fire raged. Fortunately only two people were killed, although some students were forced to spend several consecutive days at school. The featured image was taken by a local resident soon after the storm. Although all of this snow eventually melted, repeated snow storms like this help build lasting glaciers in snowy regions of our planet Earth. via NASA http://ift.tt/2rqTSYA

Old Moon in the New Moon s Arms


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. via NASA http://ift.tt/2FXjHml

Friday, January 19, 2018

Clouds in the LMC


An alluring sight in southern skies, the Large Magellanic Cloud (LMC) is seen in this deep and detailed telescopic mosaic. Recorded with broadband and narrowband filters, the scene spans some 5 degrees or 10 full moons. The narrowband filters are designed to transmit only light emitted by hydrogen, and oxygen atoms. Ionized by energetic starlight, the atoms emit their characteristic light as electrons are recaptured and the atoms transition to a lower energy state. As a result, in this image the LMC seems covered with its own clouds of ionized gas surrounding its massive, young stars. Sculpted by the strong stellar winds and ultraviolet radiation, the glowing clouds, dominated by emission from hydrogen, are known as H II (ionized hydrogen) regions. Itself composed of many overlapping H II regions, the Tarantula Nebula is the large star forming region at the left. The largest satellite of our Milky Way Galaxy, the LMC is about 15,000 light-years across and lies a mere 160,000 light-years away toward the constellation Dorado. via NASA http://ift.tt/2Dm6ENt

Wednesday, January 17, 2018

In the Valley of Orion


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. via NASA http://ift.tt/2B5EHUd

Tuesday, January 16, 2018

An Elephant s Trunk in Cepheus


With image data from telescopes large and small, this close-up features the dusty Elephant's Trunk Nebula. It winds through the emission nebula and young star cluster complex IC 1396, in the high and far off constellation of Cepheus. Also known as vdB 142, the cosmic elephant's trunk is over 20 light-years long. The colorful view highlights bright, swept-back ridges that outline the region's pockets of cool interstellar dust and gas. Such embedded, dark, tendril-shaped clouds contain the raw material for star formation and hide protostars within. Nearly 3,000 light-years distant, the relatively faint IC 1396 complex covers a large region on the sky, spanning over 5 degrees. This dramatic scene spans a 1 degree wide field, about the size of 2 Full Moons. via NASA http://ift.tt/2Db580z

Sunday, January 14, 2018

Rigel and the Witch Head Nebula


By starlight this eerie visage shines in the dark, a crooked profile evoking its popular name, the Witch Head Nebula. In fact, this entrancing telescopic portrait gives the impression that the witch has fixed her gaze on Orion's bright supergiant star Rigel. More formally known as IC 2118, the Witch Head Nebula spans about 50 light-years and is composed of interstellar dust grains reflecting Rigel's starlight. The blue color of the Witch Head Nebula and of the dust surrounding Rigel is caused not only by Rigel's intense blue starlight but because the dust grains scatter blue light more efficiently than red. The same physical process causes Earth's daytime sky to appear blue, although the scatterers in Earth's atmosphere are molecules of nitrogen and oxygen. Rigel, the Witch Head Nebula, and gas and dust that surrounds them lie about 800 light-years away. via NASA http://ift.tt/2DdfY5t

Friday, January 12, 2018

Blue Comet PanSTARRS


Discovered with the PanSTARRS telescope on September 7, 2016, this Comet PanSTARRS, C/2016 R2, is presently about 24 light minutes (3 AU) from the Sun, sweeping through planet Earth's skies across the background of stars in the constellation Taurus. An inbound visitor from our Solar System's distant Oort Cloud, its beautiful and complex ion tail is a remarkable shade of blue. Still relatively far from the Sun, the comet's already well-developed ion tail is very impressive. Emission from unusually abundant ionized carbon monoxide (CO+) atoms fluorescing in the increasing sunlight is largely responsible for the pretty blue tint. This color image of the blue comet is a combination of data taken from two different telescopes during the night of January 7. Located at the apex of the V-shaped Hyades star cluster in Taurus, bright star Gamma Tauri is responsible for the glow at the bottom left corner of the frame. via NASA http://ift.tt/2qQZf39

Thursday, January 11, 2018

RCW 114: A Dragon s Heart in Ara


Large and dramatically shaped, this cosmic cloud spans nearly 7 degrees or 14 full moons across planet Earth's sky toward the southern constellation Ara. Difficult to image, the filamentary apparition is cataloged as RCW 114 and traced in this telescopic mosaic by the telltale reddish emission of ionized hydrogen atoms. In fact, RCW 114 has been recognized as a supernova remnant. Its extensive filaments of emission are produced as the still expanding shockwave from the death explosion of a massive star sweeps up the surrounding interstellar medium. Consistent estimates place its distance at over 600 light-years, indicating a diameter of about 100 light-years or so. Light from the supernova explosion that created RCW 114 would have reached Earth around 20,000 years ago. A neutron star or pulsar has recently been identified as the collapsed remains of the stellar core. via NASA http://ift.tt/2mm1tTg

Wednesday, January 10, 2018

NGC 2623: Merging Galaxies from Hubble


Where do stars form when galaxies collide? To help find out, astronomers imaged the nearby galaxy merger NGC 2623 in high resolution with the Hubble Space Telescope. Analysis of this and other Hubble images as well as images of NGC 2623 in infrared light by the Spitzer Space Telescope, in X-ray light by XMM-Newton, and in ultraviolet light by GALEX, indicate that two originally spiral galaxies appear now to be greatly convolved and that their cores have unified into one active galactic nucleus (AGN). Star formation continues around this core near the featured image center, along the stretched out tidal tails visible on either side, and perhaps surprisingly, in an off-nuclear region on the upper left where clusters of bright blue stars appear. Galaxy collisions can take hundreds of millions of years and take several gravitationally destructive passes. NGC 2623, also known as Arp 243, spans about 50,000 light years and lies about 250 million light years away toward the constellation of the Crab (Cancer). Reconstructing the original galaxies and how galaxy mergers happen is often challenging, sometimes impossible, but generally important to understanding how our universe evolved. via NASA http://ift.tt/2CVMj1y

Sunday, January 7, 2018

Clouds of Andromeda


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. via NASA http://ift.tt/2F6f74J

Saturday, January 6, 2018

A Tether in Space


One of the greatest unrequited legends of outer space is the tether. Tethers, long strands of material, hold the promise of stabilizing satellites, generating electricity, and allowing easy transportation. Possibly the most ambitious vision of the space tether is the space elevator popularized by Arthur C. Clarke, where a tether is constructed that connects the ground to geosynchronous orbit. One problem is strength - it is difficult to make a long useful tether that does not snap. Pictured here is the deployment of the Tethered Satellite System 1 (TSS-1) by the space shuttle Altantis in 1992. Like other tested tethers, TSS-1 failed to live up to its promise, although many valuable lessons were learned. via NASA http://ift.tt/2AyU3jX

Thursday, January 4, 2018

Carina over Lake Ballard


A jewel of the southern sky, the Great Carina Nebula, also known as NGC 3372, is one of our galaxy's largest star forming regions. Easily visible to the unaided eye it stands high above the signature hill of Lake Ballard, ephemeral salt lake of Western Australia, in this serene night skyscape from December 25, 2017. The Milky Way itself stretches beyond the southern horizon. Along the Milky Way, bright stars Alpha and Beta Centauri lie just above the hill's right flank, with the Southern Cross and dark Coalsack Nebula above the hill top. Based on a 22 panel mosaic, the scene was cropped to reveal more closely the beauty of this region of the southern Milky Way. On that short summer night, a star tracking camera mount was used to record the mosaic images of the sky, but turned off to image the foreground in moonlight. via NASA http://ift.tt/2AllL3u

M1: The Incredible Expanding Crab


The Crab Nebula is cataloged as M1, the first on Charles Messier's famous list of things which are not comets. In fact, the Crab is now known to be a supernova remnant, an expanding cloud of debris from the explosion of a massive star. The violent birth of the Crab was witnessed by astronomers in the year 1054. Roughly 10 light-years across today, the nebula is still expanding at a rate of over 1,000 kilometers per second. Over the past decade, its expansion has been documented in this stunning time-lapse movie. In each year from 2008 to 2017, an image was produced with the same telescope and camera from a remote observatory in Austria. Combined in the time-lapse movie, the 10 images represent 32 hours of total integration time. The sharp, processed frames even reveal the dynamic energetic emission within the incredible expanding Crab. The Crab Nebula lies about 6,500 light-years away in the constellation Taurus. via NASA http://ift.tt/2lPMoZZ