Tuesday, March 28, 2017

Hubble's Glittering Frisbee Galaxy

This image from Hubble's Wide Field Camera 3 (WFC3) shows a section of NGC 1448, a spiral galaxy located about 50 million light-years from Earth in the little-known constellation of Horologium (The Pendulum Clock). We tend to think of spiral galaxies as massive and roughly circular celestial bodies, so this glittering oval does not immediately appear to fit the visual bill. What's going on?

Imagine a spiral galaxy as a circular frisbee spinning gently in space. When we see it face on, our observations reveal a spectacular amount of detail and structure '” a great example from Hubble is the telescope's view of Messier 51, otherwise known as the Whirlpool Galaxy. However, the NGC 1448 frisbee is very nearly edge-on with respect to Earth, giving it an appearance that is more oval than circular. The spiral arms, which curve out from NGC 1448's dense core, can just about be seen.

Although spiral galaxies might appear static with their picturesque shapes frozen in space, this is very far from the truth. The stars in these dramatic spiral configurations are constantly moving as they orbit around the galaxy's core, with those on the inside making the orbit faster than those sitting further out.

This makes the formation and continued existence of a spiral galaxy's arms something of a cosmic puzzle, because the arms wrapped around the spinning core should become wound tighter and tighter as time goes on '” but this is not what we see. This is known as the winding problem.

For Hubble's image of the Whirlpool Galaxy, visit: andnbsp;andnbsp;

http://hubblesite.org/image/1677/news_release/2005-12

Image credit: ESA/Hubble andamp; NASA

Text credit: European Space Agency

Hubble Space Telescope

Thursday, March 16, 2017

Farewell to Mimas

In its season of "lasts," NASA's Cassini spacecraft made its final close approach to Saturn's moon Mimas on January 30, 2017. At closest approach, Cassini passed 25,620 miles (41,230 kilometers) from Mimas. All future observations of Mimas will be from more than twice this distance.

This mosaic is one of the highest resolution views ever captured of the icy moon.

Close approaches to Mimas have been somewhat rare during Cassini's mission, with only seven flybys at distances of less than 31,000 miles (50,000 kilometers).

Mimas' surface is pockmarked with countless craters, the largest of which gives the icy moon its distinctive appearance. (See PIA12568 for more info on Mimas' distinctive crater, Herschel.)

Two versions of the mosaic are provided. In one, the left side, which is lit by reflected light from Saturn, has been enhanced in brightness in order to show the full surface. The second version features more natural illumination levels.

Imaging scientists combined ten narrow-angle camera images to create this mosaic view. The scene is an orthographic projection centered on terrain at 17.5 degrees south latitude, 325.4 degrees west longitude on Mimas. An orthographic view is most like the view seen by a distant observer looking through a telescope.

This mosaic was acquired at a distance of approximately 28,000 miles (45,000 kilometers) from Mimas. Image scale is approximately 820 feet (250 meters) per pixel. The images were taken in visible light with the Cassini spacecraft narrow-angle camera on Jan. 30, 2017.

The Cassini mission is a cooperative project of NASA, ESA (the European Space Agency) and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colorado.

Image Credit: NASA/JPL-Caltech/Space Science Institute

Cassini

The Cone Nebula From Hubble

Stars are forming in the gigantic dust pillar called the Cone Nebula. Cones, pillars, and majestic flowing shapes abound in stellar nurseries where natal clouds of gas and dust are buffeted by energetic winds from newborn stars. The Cone Nebula, a well-known example, lies within the bright galactic star-forming region NGC 2264. The Cone was captured in unprecedented detail in this close-up composite of several observations from the Earth-orbiting Hubble Space Telescope. While the Cone Nebula, about 2,500 light-years away in Monoceros, is around 7 light-years long, the region pictured here surrounding the cone's blunted head is a mere 2.5 light-years across. In our neck of the galaxy that distance is just over half way from our Sun to its nearest stellar neighbors in the Alpha Centauri star system. The massive star NGC 2264 IRS, seen by Hubble's infrared camera in 1997, is the likely source of the wind sculpting the Cone Nebula and lies off the top of the image. The Cone Nebula's reddish veil is produced by glowing hydrogen gas.
Image Credit: Hubble Legacy ArchiveNASAESA - Processing & LicenceJudy Schmidt

Hubble Space Telescope

Wednesday, March 15, 2017

Mimas the Big One

Mimas' gigantic crater Herschel lies near the moon's limb in this Cassini view.

A big enough impact could potentially break up a moon. Luckily for Mimas, whatever created Herschel was not quite big enough to cause that level of disruption.

When large impacts happen, they deliver tremendous amounts of energy -- sometimes enough to cause global destruction.  Even impacts that are not catastrophic can leave enormous, near-permanent scars on bodies like Mimas (246 miles or 396 kilometers across).

This view looks toward the anti-Saturn hemisphere of Mimas. North on Mimas is up and rotated 32 degrees to the left. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Nov. 19, 2016.

The view was acquired at a distance of approximately 53,000 miles (85,000 kilometers) from Mimas. Image scale is 1,677 feet (511 meters) per pixel.

The Cassini mission is a cooperative project of NASA, ESA (the European Space Agency) and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colorado.

The Cassini mission is a cooperative project of NASA, ESA (the European Space Agency) and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colorado.

Credit: NASA/JPL-Caltech/Space Science Institute

Cassini

A Dark Winter Sky Over Monfrague National Park in Spain

You, too, can see a night sky like this. That is because Monfrague National Park inSpain, where this composite image was created, has recently had its night sky officially protected from potential future light pollution. Icons of the night sky that should continue to stand out during northern winter -- and are visible on the featured image -- include very bright stars like SiriusBetelgeuse, and Procyon, bright star clusters like the Pleiades, and, photographically, faint nebulas like theCalifornia and Rosette Nebulas. Even 100 years ago, many people were more familiar with a darker night sky than people today, primarily because of the modern light pollution. Other parks that have been similarly protected as dark-sky preserves include Death Valley National Park (USA) and Grasslands National Park(Canada). Areas such as the city of Flagstaff, Arizona and much of the Big Island of Hawaii also have their night skies protected.
Image Credit & Copyright: José Luis Quiñones (Entre Encinas y Estrellas)

Sunday, March 12, 2017

At the Heart Of Orion

Near the center of this sharp cosmic portrait, at the heart of the Orion Nebula, are four hot, massive stars known as the Trapezium. Tightly gathered within a regionabout 1.5 light-years in radius, they dominate the core of the dense Orion Nebula Star Cluster. Ultraviolet ionizing radiation from the Trapezium stars, mostly from the brightest star Theta-1 Orionis C powers the complex star forming region's entire visible glow. About three million years old, the Orion Nebula Cluster was even more compact in its younger years and a dynamical study indicates thatrunaway stellar collisions at an earlier age may have formed a black hole with more than 100 times the mass of the Sun. The presence of a black hole within the cluster could explain the observed high velocities of the Trapezium stars. The Orion Nebula's distance of some 1,500 light-years would make it the closest known black hole to planet Earth.
Image Credit & CopyrightChristoph KaltseisCEDIC 2017

Saturday, March 11, 2017

Reflections on vdB31

Riding high in the constellation of Auriga, beautiful, blue vdB 31 is the 31st objectin Sidney van den Bergh's 1966 catalog of reflection nebulae. It shares this well-composed celestial still life with dark, obscuring clouds recorded in Edward E. Barnard's 1919 catalog of dark markings in the sky. All are interstellar dust clouds, blocking the light from background stars in the case of Barnard's dark nebulae. For vdB 31, the dust preferentially reflects the bluish starlight from embedded, hot, variable star AB Aurigae. Exploring the environs of AB Aurigae with the Hubble Space Telescope has revealed the several million year young star is itself surrounded by flattened dusty disk with evidence for the ongoing formation of a planetary system. AB Aurigae is about 470 light-years away. At that distance this cosmic canvas would span about four light-years.
Image Credit & CopyrightAdam BlockMt. Lemmon SkyCenterU. Arizona

Hubble Hones in On a Hypergiant's a Homes

This beautiful Hubble image reveals a young super star cluster known as Westerlund 1, only 15,000 light-years away in our Milky Way neighborhood, yet home to one of the largest stars ever discovered.

Stars are classified according to their spectral type, surface temperature, and luminosity. While studying and classifying the cluster’s constituent stars, astronomers discovered that Westerlund 1 is home to an enormous star.  Originally named Westerlund 1-26, this monster star is a red supergiant (although sometimes classified as a hypergiant) with a radius over 1,500 times that of our sun. If Westerlund 1-26 were placed where our sun is in our solar system, it would extend out beyond the orbit of Jupiter.

Most of Westerlund 1’s stars are thought to have formed in the same burst of activity, meaning that they have similar ages and compositions. The cluster is relatively young in astronomical terms —at around three million years old it is a baby compared to our own sun, which is some 4.6 billion years old.

Image credit: ESA/Hubble & NASA
Text credit: European Space Agency

Hubble Space Telescope

Wednesday, March 8, 2017

Dust, Gas, and Stars in the Orion Nebula



Explanation: The Great Nebula in Orion, an immense, nearby starbirth region, is probably the most famous of all astronomical nebulas. Here, filaments of dark dust and glowing gas surround hot young stars at the edge of an immense interstellar molecular cloud only 1500 light-years away. In the featured deep image shown in assigned colors, part of the nebula's center is shown as taken by the Hubble Space Telescope. The Great Nebula in Orion can be found with the unaided eye near the easily identifiable belt of three stars in the popular constellation Orion. In addition to housing a bright open cluster of stars known as the Trapezium, the Orion Nebula contains many stellar nurseries. These nurseries contain much hydrogen gas, hot young stars, proplyds, and stellar jets spewing material at high speeds. Also known as M42 and M43, the Orion Nebula spans about 40 light years and is located in the same spiral arm of our Galaxy as the Sun.

 Image Credit: NASAESAHubbleHLAReprocessing & Copyright: Jesús M.Vargas & Maritxu Poyal


Monday, March 6, 2017

The Mysterious Rings of Supernova

What's causing those odd rings in supernova 1987A? Thirty years ago, in 1987, the brightest supernova in recent history was seen in the Large Magellanic Cloud. At the center of the featured picture is an object central to the remains of the violent stellar explosion. Surrounding the center are curious outer rings appearing as aflattened figure 8. Although large telescopes including the Hubble Space Telescope monitor the curious rings every few years, their origin remains a mystery. Pictured here is a Hubble image of the SN1987A remnant taken in 2011.Speculation into the cause of the rings includes beamed jets emanating from an otherwise hidden neutron star left over from the supernova, and the interaction of the wind from the progenitor star with gas released before the explosion.
Image Credit: ESA/HubbleNASA

Saturday, March 4, 2017

Still life with reflection dust

In this beautiful celestial still life composed with a cosmic brush, dusty nebulaNGC 2170 shines at the upper left. Reflecting the light of nearby hot stars, NGC 2170 is joined by other bluish reflection nebulae, a compact red emission region, and streamers of obscuring dust against a backdrop of stars. Like the common household items still life painters often choose for their subjects, the clouds of gas, dust, and hot stars pictured here are also commonly found in this setting - a massive, star-forming molecular cloud in the constellation of the Unicorn (Monoceros). The giant molecular cloud, Mon R2, is impressively close, estimatedto be only 2,400 light-years or so away. At that distance, this canvas would be about 15 light-years across.
Image Credit & CopyrightAdam BlockMt. Lemmon SkyCenterU. Arizona

Friday, March 3, 2017

Hubble Showcases a Remarkable Galactic Hybrid

This NASA/ESA Hubble Space Telescope image showcases the remarkable galaxy UGC 12591. UGC 12591 sits somewhere between a lenticular and a spiral. It lies just under 400 million light-years away from us in the westernmost region of the Pisces–Perseus Supercluster, a long chain of galaxy clusters that stretches out for hundreds of light-years — one of the largest known structures in the cosmos.

The galaxy itself is also extraordinary: it is incredibly massive. The galaxy and its halo together contain several hundred billion times the mass of the sun; four times the mass of the Milky Way. It also whirls round extremely quickly, rotating at speeds of up to 1.8 million kilometers (1.1 million miles) per hour.

Observations with Hubble are helping astronomers to understand the mass of UGC 1259, and to determine whether the galaxy simply formed and grew slowly over time, or whether it might have grown unusually massive by colliding and merging with another large galaxy at some point in its past.

Image credit: ESA/Hubble & NASA

Text credit: European Space Agency

Hubble Space Telescope

At the Centre of Saturn

The north pole of Saturn sits at the center of its own domain. Around it swirl the clouds, driven by the fast winds of Saturn. Beyond that orbits Saturn's retinue of moons and the countless small particles that form the ring.

Although the poles of Saturn are at the center of all of this motion, not everything travels around them in circles. Some of the jet-stream patterns, such as the hexagon-shaped pattern seen here, have wavy, uneven shapes. The moons as well have orbits that are elliptical, some quite far from circular.

This view looks toward the sunlit side of the rings from about 26 degrees above the ring plane. The image was taken with the Cassini spacecraft wide-angle camera on Dec. 2, 2016 using a spectral filter which preferentially admits wavelengths of near-infrared light centered at 890 nanometers.

The view was acquired at a distance of approximately 619,000 miles (996,000 kilometers) from Saturn. Image scale is 37 miles (60 kilometers) per pixel.

The Cassini mission is a cooperative project of NASA, ESA (the European Space Agency) and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colorado.

Credit: NASA/JPL-Caltech/Space Science Institute

Cassini

Thursday, March 2, 2017

Juno Captures Jupiters Cloudscape in High Resolution

This close-up view of Jupiter captures the turbulent region just west of the Great Red Spot in the South Equatorial Belt, with resolution better than any previous pictures from Earth or other spacecraft.

NASA's Juno spacecraft captured this image with its JunoCam citizen science instrument when the spacecraft was a mere 5,400 miles (8,700 kilometers) above Jupiter's cloudtops on Dec. 11, 2016 at 9:14 a.m. PT (12:14 p.m. ET). Citizen scientist Sergey Dushkin produced the sublime color processing and cropped the image to draw viewers' eyes to the dynamic clouds.

JunoCam's raw images are available at www.missionjuno.swri.edu/junocam for the public to peruse and process into image products.

Credits: NASA/JPL-Caltech/SwRI/MSSS/Sergey Dushkin

Juno

This is a Recent Solar Eclipse


 Image Credit & Copyright: Stephen Bedingfield

What kind of eclipse is this? On Sunday, visible in parts of Earth's southern hemisphere, the Moon blocked part of the Sun during a partial solar eclipse. In some locations, though, the effect was a rare type of partial eclipse called an annular eclipse. There, since the Moon is too far from the Earth to block the entire Sun, sunlight streamed around the edges of the Moon creating a "ring of fire". At some times, though, the effect was a rare type of annular eclipse. Then, an edge of the Moon nearly aligned with an edge of the Sun, allowing sunlight to stream through only low areas on the Moon. Called a "Baily's bead" or a "diamond ring", this doubly rare effect was captured Sunday in the feature photograph from Chubut, Argentina, in South America. This summer a total solar eclipse will swoop acrossNorth America.

Annular Eclipse After Sunrise


Image Credit & Copyright
Vincent Bouchama

From northern Patagonia, morning skies were clear and blue on Sunday, February 26. This sweeping composite scene, overlooking Hermoso Valle, Facundo, Chubut, Argentina, follows the Sun after sunrise, capturing an annular solar eclipse. Created from a series of exposures at three minute intervals, it shows the year's first solar eclipse beginning well above the distant eastern horizon. An exposure close to mid-eclipse recorded the expected ring of fire, the silhouette of the New Moon only slightly too small to cover the bright Sun. At that location on planet Earth, the annular phase of the eclipse lasted a brief 45 seconds.