Space

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The Dawn of a New Era in Human Spaceflight



"The dawn of a new era in human spaceflight." — Astronaut Anne McClain

McClain had an unparalleled view from orbit of SpaceX's Crew Dragon spacecraft as it approached the International Space Station on Sunday, March 3, 2019. The Crew Dragon docked autonomously to the orbiting laboratory, a historic first for a commercially built and operated American crew spacecraft. This uncrewed test flight is providing valuable information to help verify that Crew Dragon will provide astronauts a safe, comfortable and enjoyable ride to space.

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A February without Sunspots



Where have all the sunspots gone? Last month the total number of spots that crossed our Sun was ... zero. Well below of the long term monthly average, the Sun's surface has become as unusually passive this solar minimum just like it did 11 years ago during the last solar minimum. Such passivity is not just a visual spectacle, it correlates with the Sun being slightly dimmer, with holes in the Sun's corona being more stable, and with a reduced intensity in the outflowing solar wind.

The reduced wind, in turn, cools and collapses Earth's outer atmosphere (the thermosphere), causing reduced drag on many Earth-orbiting satellites. Pictured in inverted black & white on the left, the Sun's busy surface is shown near solar maximum in 2012, in contrast to the image on the right, which shows the Sun's surface last August, already without spots (for a few days), as solar minimum was setting in. Effects of this unusually static solar minimum are being studied.

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Ann R. McNair and Mary Jo Smith with Model of Pegasus Satellite, July 14, 1964



A native of Moundville, Alabama, Ann McNair earned a bachelor’s degree in physics and mathematics from the University of Alabama in Tuscaloosa in 1958. She arrived at Redstone Arsenal that same year taking a position as Mathematician with the Army Ballistic Missile Agency. McNair’s involvement in the Saturn program included her role as deputy manager of the Orbital Analysis Branch developing flight trajectory studies and determining how long satellites might remain in orbit.

Early on, McNair authored several papers on the lifetime of satellites and on comparing onboard and ground tracking for lunar missions. In 1965, McNair published the article “Orbital Tracking and Decay Analysis of the Saturn I Flights” in the Journal of Spacecraft and Rockets. From 1965 to 1967, McNair served as a group chief within the Information Systems Office, supporting the planning and execution of all Apollo flights.

Mary Jo Smith was a physicist with a bachelor’s degree from Texas Christian University, assigned to the Marshall’s Research Projects Division to work on plans for the Pegasus meteoroid detection satellites that the Center launched aboard a Saturn I rocket in the early 1960s.

During the Skylab program, Smith served as manager of the Ultra-Violet Panorama Experiment (S183), an instrument developed for the Apollo Telescope Mount by the Laboratories d’Astronomie Spatiale in Marseille, France under the direction of that laboratory’s director, Dr. Georges Courtes.

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Stardust and Starlight in M78



Interstellar dust clouds and bright nebulae abound in the fertile constellation of Orion. One of the brightest, M78, is near the center in this colorful telescopic view, covering an area north of Orion's belt. At a distance of about 1,500 light-years, the bluish nebula itself is about 5 light-years across. Its blue tint is due to dust preferentially reflecting the blue light of hot, young stars in the region.

Dark dust lanes and other nebulae can easily be traced through the gorgeous skyscape that includes many Herbig- Haro objects, energetic jets from stars in the process of formation. But missing from this image is McNeil's nebula. A major discovery only recognized in 2004, the enigmatic, variable nebula was found along the dark lane of dust above and right of larger M78.

McNeil's nebula is associated with a protostar and seen to be sometimes present and sometimes absent in photos of the well-imaged region. McNeil's nebula faded from view late last year and is still absent in this deep image recorded in February 2019.

cdlee4

I love thinking about space. If it was possible to just keep going i wonder what you would find. Would it be like The Truman Show and you just run into a wall somewhere, how long would you keep traveling? I can pick up a box in my hands and it has finite boundaries but space....does it have any finite boundaries? Or, how can something possibly continue on forever without reaching a stopping point. If there is a stopping point, wth would be past that? wow, my mind just gets blown.

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cdlee4

JustReadTheInstructions wrote: »

cdlee4 wrote: »

I love thinking about space. If it was possible to just keep going i wonder what you would find. Would it be like The Truman Show and you just run into a wall somewhere, how long would you keep traveling? I can pick up a box in my hands and it has finite boundaries but space....does it have any finite boundaries? Or, how can something possibly continue on forever without reaching a stopping point. If there is a stopping point, wth would be past that? wow, my mind just gets blown.

This is an interesting thought. There's the "observable" universe and then there's... the rest of it. Basically anything, if there is anything, outside the observable universe hasn't had enough time for its light to reach us. I'm guessing it's just more of the same. Stars, galaxies, etc.

But is it expanding? If so what is the space that it's expanding into? If it just goes on and on forever then what do you think of the theory that there are infinite Earth copies and parallel worlds...

I think that's the fun part to think about, we just don't know! There could be copies and parallel worlds, we just don't know

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The Central Magnetic Field of the Cigar Galaxy



Are galaxies giant magnets? Yes, but the magnetic fields in galaxies are typically much weaker than on Earth's surface, as well as more complex and harder to measure. Recently, though, the HAWC+ instrument onboard the airborne (747) SOFIA observatory has been successful in detailing distant magnetic fields by observing infrared light polarized by reflection from dust grains.

Featured here, HAWC+ observations of the M82, the Cigar galaxy, show that the central magnetic field is perpendicular to the disk and parallel to the strong supergalactic wind. This observation bolsters the hypothesis that M82's central magnetic field helps its wind transport the mass of millions of stars out from the central star-burst region. The featured image shows magnetic field lines superposed on top of an optical light (gray) and hydrogen gas (red) image from Kitt Peak National Observatory, further combined with infrared images (yellow) from SOFIA and the Spitzer Space Telescope.

The Cigar Galaxy is about 12 million light years distant and visible with binoculars towards the constellation of the Great Bear.

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Touchdown on Asteroid Ryugu

Hayabusa2 Touch down
https://www.youtube.com/watch?v=-3hO58HFa1M

Last month, humanity bounced a robot off an asteroid. The main reason was to collect a surface sample. Despite concern over finding a safely reboundable touchdown spot, Japan's robotic Hayabusa2 spacecraft successfully touched down -- and bounced right back from -- asteroid Ryugu. Before impact, Hayabusa2 fired a small bullet into 162173 Ryugu to scattered surface material and increase the chance that Hayabusa2 would be able to capture some.

Next month, Hayabusa2 will fire a much larger bullet into Ryugu in an effort to capture sub-surface material. Near the end of this year, Hayabusa2 is scheduled to depart Ryugu and begin a looping trip back to Earth, hopefully returning small pieces of this near-Earth asteroid in late 2020. Studying Ryugu could tell humanity not only about the minor planet's surface and interior, but about what materials were available in the early Solar System for the development of life.

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Crescent Enceladus



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 collected during Cassini's flybys and years of images have revealed the presence of remarkable south polar geysers and a possible global ocean of liquid water beneath an icy crust.

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Highlights of the North Spring Sky



What can you see in the night sky this season? The featured graphic gives a few highlights for Earth's northern hemisphere. Viewed as a clock face centered at the bottom, early (northern) spring sky events fan out toward the left, while late spring events are projected toward the right.

Objects relatively close to Earth are illustrated, in general, as nearer to the cartoon figure with the telescope at the bottom center -- although almost everything pictured can be seen without a telescope. As happens during any season, constellations appear the same year to year, and, as usual, the Lyrids meteor shower will peak in mid-April. Also as usual, the International Space Station (ISS) can be seen, at times, as a bright spot drifting across the sky after sunset.

After the Vernal Equinox next week, the length of daytime will be greater than the length of nighttime in Earth's northern hemisphere, an inequality that will escalate as the spring season develops. Also as spring ages, Jupiter becomes visible increasingly earlier in the night. As spring draws to a close, the month of May will feature two full moons, the second of which is called a Blue Moon.

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Pleiades Deep Field



Have you ever seen the Pleiades star cluster? Even if you have, you probably have never seen it like this: all dusty. Perhaps the most famous star cluster on the sky, the bright stars of the Pleiades can be seen without binoculars from even the depths of a light-polluted city. With a long exposure from a dark location, though, the dust cloud surrounding the Pleiades star cluster becomes very evident.

The above exposure took about 30 hours and covers a sky area several times the size of the full moon. Also known as the Seven Sisters and M45, the Pleiades lies about 400 light years away toward the constellation of the Bull (Taurus). A common legend with a modern twist is that one of the brighter stars faded since the cluster was named, leaving only six stars visible to the unaided eye. The actual number of Pleiades stars visible, however, may be more or less than seven, depending on the darkness of the surrounding sky and the clarity of the observer's eyesight.

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Perseverance Valley Panorama



Mars exploration rover Opportunity's parting panorama from Perseverance Valley spans 360 degrees in this false color mosaic. The scene is composed of 354 individual images recorded through 3 different color filters by the rover's panoramic camera from May 13 through June 10, 2018. A few frames remain in black and white at the lower left though.

Those were obtained through only one filter just before a dust storm engulfed Mars in June 2018, ultimately ending the solar-powered rover's trailblazing 15 year mission. Just right of center, the annotation identifies Opportunity's entry point to Perseverance Valley along the Endeavor crater's western rim. The rover's tracks begin there, extending from over the horizon toward the far right and its final resting spot on the Red Planet.

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Flame Nebula Close-Up



Of course, the Flame Nebula is not on fire. Also known as NGC 2024, the nebula's suggestive reddish color is due to the glow of hydrogen atoms at the edge of the giant Orion molecular cloud complex some 1,500 light-years away. The hydrogen atoms have been ionized, or stripped of their electrons, and glow as the atoms and electrons recombine. But what ionizes the hydrogen atoms?

In this close-up view, the central dark lane of absorbing interstellar dust stands out in silhouette against the hydrogen glow and actually hides the true source of the Flame Nebula's energy from optical telescopes. Behind the dark lane lies a cluster of hot, young stars, seen at infrared wavelengths through the obscuring dust. A young, massive star in that cluster is the likely source of energetic ultraviolet radiation that ionizes the hydrogen gas in the Flame Nebula.

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A View Toward M101



Big, beautiful spiral galaxy M101 is one of the last entries in Charles Messier's famous catalog, but definitely not one of the least. About 170,000 light-years across, this galaxy is enormous, almost twice the size of our own Milky Way galaxy. M101 was also one of the original spiral nebulae observed by Lord Rosse's large 19th century telescope, the Leviathan of Parsontown. M101 shares this modern telescopic field of view with more distant background galaxies, foreground stars within the Milky Way, and a companion dwarf galaxy NGC 5474 (lower right).

The colors of the Milky Way stars can also be found in the starlight from the large island universe. Its core is dominated by light from cool yellowish stars. Along its grand design spiral arms are the blue colors of hotter, young stars mixed with obscuring dust lanes and pinkish star forming regions. Also known as the Pinwheel Galaxy, M101 lies within the boundaries of the northern constellation Ursa Major, about 23 million light-years away.

Its companion NGC 5474 has likely been distorted by its past gravitational interactions with the dominant M101.

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Abell 370: Galaxy Cluster Gravitational Lens



What are those strange arcs? While imaging the cluster of galaxies Abell 370, astronomers noticed an unusual arc. The arc wasn't understood right away -- not until better images showed that the arc was a previously unseen type of astrophysical artifact of a gravitational lens, where the lens was the center of an entire cluster of galaxies. Today, we know that this arc, the brightest arc in the cluster, actually consists of two distorted images of a fairly normal galaxy that happens to lie far in the distance.

Abell 370's gravity caused the background galaxies' light -- and others -- to spread out and come to the observer along multiple paths, not unlike a distant light appears through the stem of a wine glass. Almost all of the yellow images featured here are galaxies in the Abell 370 cluster. An astute eye can pick up many strange arcs and distorted arclets, however, that are actually gravitationally lensed images of distant normal galaxies. Studying Abell 370 and its images gives astronomers a unique window into the distribution of normal and dark matter in galaxy clusters and the universe.

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Dark Clouds of the Carina Nebula



What dark forms lurk in the mists of the Carina Nebula? These ominous figures are actually molecular clouds, knots of molecular gas and dust so thick they have become opaque. In comparison, however, these clouds are typically much less dense than Earth's atmosphere. Pictured above is part of the most detailed image of the Carina Nebula ever taken, a part where dark molecular clouds are particularly prominent. The image has recently been retaken and then re-colored based on light emitted by oxygen.

The entire Carina Nebula spans over 300 light years and lies about 7,500 light-years away in the constellation of Carina. NGC 3372, known as the Great Nebula in Carina, is home to massive stars and changing nebula. Eta Carinae, the most energetic star in the nebula, was one of the brightest stars in the sky in the 1830s, but then faded dramatically. Wide-field annotated and zoomable versions of the larger image composite are also available.

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Close Comet and Large Magellanic Cloud



Sporting a surprisingly bright, lovely green coma Comet 252P/Linear poses next to the Large Magellanic Cloud in this southern skyscape. The stack of telephoto exposures was captured on March 16 from Penwortham, South Australia. Recognized as a Jupiter family periodic comet, 252P/Linear will come close to our fair planet on March 21, passing a mere 5.3 million kilometers away.

That's about 14 times the Earth-Moon distance. In fact, it is one of two comets that will make remarkably close approaches in the next few days as a much fainter Comet Pan-STARRS (P/2016 BA14) comes within 3.5 million kilometers (9 times the Earth-Moon distance) on March 22. The two have extremely similar orbits, suggesting they may have originally been part of the same comet. Sweeping quickly across the sky because of their proximity to Earth, both comets will soon move into northern skies.

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Hubble Captures the Brilliant Heart of a Massive Galaxy



This fuzzy orb of light is a giant elliptical galaxy filled with an incredible 200 billion stars. Unlike spiral galaxies, which have a well-defined structure and boast picturesque spiral arms, elliptical galaxies appear fairly smooth and featureless. This is likely why this galaxy, named Messier 49 (M49), was discovered by French astronomer Charles Messier in 1771. At a distance of 56 million light-years and measuring 157,000 light-years across, M49 was the first member of the Virgo Cluster of galaxies to be discovered, and it is more luminous than any other galaxy at its distance or nearer.

Elliptical galaxies tend to contain a larger portion of older stars than spiral galaxies and also lack young, blue stars. Messier 49 itself is very yellow, which indicates that the stars within it are mostly older and redder than the Sun. In fact, the last major episode of star formation within the galaxy was about six billion years ago — before the Sun was even born!

Messier 49 is also rich in globular star clusters; it hosts about 6,000 — a number that dwarfs the 150 found in and around the Milky Way. On average, these clusters are 10 billion years old. Messier 49 is also known to host a supermassive black hole at its center with the mass of more than 500 million Suns, identifiable by the X-rays pouring out from the heart of the galaxy. (As this Hubble image comprises optical and infrared observations, these X-rays are not visible here.)

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AE Aurigae and the Flaming Star Nebula



Is star AE Aurigae on fire? No. Even though AE Aurigae is named the flaming star, the surrounding nebula IC 405 is named the Flaming Star Nebula, and the region shape gives the appearance of fire, there is no fire. Fire, typically defined as the rapid molecular acquisition of oxygen, happens only when sufficient oxygen is present and is not important in such high-energy, low-oxygen environments such as stars.

The material that appears as smoke is mostly interstellar hydrogen, but does contain smoke-like dark filaments of carbon-rich dust grains. The bright star AE Aurigae, visible just to the lower right of the image center, is so hot it glows blue, emitting light so energetic it knocks electrons away from surrounding gas. When a proton recaptures an electron, light is emitted, as seen in the surrounding emission nebula.

Featured here, the Flaming Star nebula lies about 1,500 light years distant, spans about 5 light years, and is visible with a small telescope toward the constellation of the Charioteer (Auriga).

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NGC 1333: Stellar Nursery in Perseus



NGC 1333 is seen in visible light as a reflection nebula, dominated by bluish hues characteristic of starlight reflected by interstellar dust. A mere 1,000 light-years distant toward the heroic constellation Perseus, it lies at the edge of a large, star-forming molecular cloud. This striking close-up spans about two full moons on the sky or just over 15 light-years at the estimated distance of NGC 1333.

It shows details of the dusty region along with telltale hints of contrasty red emission from Herbig-Haro objects, jets and shocked glowing gas emanating from recently formed stars. In fact, NGC 1333 contains hundreds of stars less than a million years old, most still hidden from optical telescopes by the pervasive stardust. The chaotic environment may be similar to one in which our own Sun formed over 4.5 billion years ago.

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The Gaia Stars of M15



Messier 15 is a 13 billion year old relic of the early formative years of our galaxy, one of about 170 globular star clusters that still roam the halo of the Milky Way. About 200 light-years in diameter, it lies about 35,000 light years away toward the constellation Pegasus.

But this realistic looking view of the ancient globular star cluster is not a photograph. Instead it's an animated gif image constructed from remarkably precise individual measurements of star positions, brightness, and color. The astronomically rich data set used was made by the sky-scanning Gaia satellite which also determined parallax distances for 1.3 billion Milky Way stars.

In the animated gif, twinkling stars are M15's identified RR Lyrae stars. Plentiful in M15, RR Lyrae stars are evolved pulsating variable stars whose brightness and pulsation period, typically less than a day, are related.

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Sharpless 308: Star Bubble



Blown by fast winds from a hot, massive star, this cosmic bubble is huge. Cataloged as Sharpless 2-308 it lies some 5,200 light-years away toward the constellation of the Big Dog (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 in the expansive image is dominated by the glow of ionized oxygen atoms mapped to a blue hue.

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Hubble Watches Spun-Up Asteroid Coming Apart



A small asteroid was caught in the process of spinning so fast it’s throwing off material, according to new data from NASA’s Hubble Space Telescope and other observatories.

Images from Hubble show two narrow, comet-like tails of dusty debris streaming from the asteroid (6478) Gault. Each tail represents an episode in which the asteroid gently shed its material — key evidence that Gault is beginning to come apart.

Discovered in 1988, the 2.5-mile-wide (4-kilometer-wide) asteroid has been observed repeatedly, but the debris tails are the first evidence of disintegration. Gault is located 214 million miles (344 million kilometers) from the Sun. Of the roughly 800,000 known asteroids between Mars and Jupiter, astronomers estimate that this type of event in the asteroid belt is rare, occurring roughly once a year.

Watching an asteroid become unglued gives astronomers the opportunity to study the makeup of these space rocks without sending a spacecraft to sample them.

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Hubble Spots Flock of Cosmic Ducks



This star-studded image shows us a portion of Messier 11, an open star cluster in the southern constellation of Scutum (the Shield). Messier 11 is also known as the Wild Duck Cluster, as its brightest stars form a “V” shape that somewhat resembles a flock of ducks in flight.

Messier 11 is one of the richest and most compact open clusters currently known. By investigating the brightest, hottest main sequence stars in the cluster, astronomers estimate that it formed roughly 220 million years ago. Open clusters tend to contain fewer and younger stars than their more compact globular cousins, and Messier 11 is no exception: at its center lie many blue stars, the hottest and youngest of the cluster’s few thousand stellar residents.

The lifespans of open clusters are also relatively short compared to those of globular ones; stars in open clusters are spread farther apart and are thus not as strongly bound to each other by gravity, causing them to be more easily and quickly drawn away by stronger gravitational forces. As a result, Messier 11 is likely to disperse in a few million years as its members are ejected one by one, pulled away by other celestial objects in the vicinity.

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