Nebula N90 and SXP 1062

A composite image of a portion of the Wing of the Small Magellanic Cloud (SMC), a peripheral region of this satellite galaxy of the Milky Way. The Wing is part of the tidal feature that connects the SMC to its neighbor, the Large Magellanic Cloud.

The Wing is located at the outskirts of the SMC and is characterized by a low density of stars, gas and dust, and by low metallicity. It displays signs of recent star formation episodes that took place over the past few million years.

On the left side of the image is the iconic N90 nebula, home to NGC 602, a bright, young open cluster of stars. On the right is the newly-discovered X-ray pulsar SXP 1062, visible as a bright point-like X-ray source (shown in blue). SXP 1062 accretes mass from its stellar companion, a massive, hot, blue 'Be' star, the two objects forming a Be/X-ray binary. The X-ray emission from this object has been detected using data from ESA's XMM-Newton as well as NASA's Chandra space-based observatories.

The diffuse glow surrounding the X-ray pulsar, also visible in blue, derives from the hot gas that fills the remnant of the supernova that created the pulsar. The supernova remnant itself is also visible as a bubble-shaped feature (shown in red) enclosing the pulsar. Other point-like X-ray sources are visible in blue and are background, extragalactic objects.

This image combines a three-color composite based on optical data from NOAO's Cerro Tololo Inter-American Observatory (CTIO), obtained using two special filters that reveal the glow of oxygen and hydrogen, with X-ray data from Chandra and XMM-Newton, which are overlaid in blue.

Photo credit: X-ray: NASA/CXC/Univ.Potsdam/L. Oskinova et al & ESA/XMM-Newton; Optical: AURA/NOAO/CTIO/Univ.Potsdam/L. Oskinova et al

Note: For more information, see Strangely Slow Pulsar Discovered Nestled in Young Supernova Remnant. A similar article on the above image can be found at one of the Chandra websites; see SXP 1062: Celestial Bauble Intrigues Astronomers.

Abell 2052

The galaxy cluster Abell 2052 is found some 480 million light years from Earth. At the center of Abell 2052 is a giant elliptical galaxy, and within that is a supermassive black hole. X-ray data from Chandra show the hot gas that fills the space within the cluster. Pulling away, we see a huge spiral structure around this central elliptical galaxy. This spiral, which is over one million light years across, was created when a smaller spiral smashed into Abell 2052. This caused the hot gas in the cluster to slosh back and forth, similar to how wine moves when a glass is tugged from side to side. This sloshing turns out to be very important. First, it helps redistribute the hot gas, which, in turn, affects the number of new stars being formed in the central galaxy. The sloshing also spreads elements like oxygen and iron throughout the cluster, enriching future generations of stars and planets with the building blocks necessary for life as we know it.

Video credit: NASA/CXC/A. Hobart

Note: For more information, see Abell 2052: A Galaxy Cluster Gets Sloshed

X-Ray Pulsar SXP 1062 Embedded in a Supernova Remnant

This image is a composite view of the newly discovered X-ray pulsar SXP 1062 still embedded in the remnant of the supernova that created it. SXP 1062 accretes mass from its stellar companion, a massive, hot, blue 'Be' star, the two objects forming a Be/X-ray binary.

The X-ray emission from this object has been detected using data from ESA's XMM-Newton as well as NASA's Chandra space-based observatories. A later study of optical images of the source and its surroundings revealed the bubble-shaped signature of the supernova remnant around the binary system. Since supernova remnants shine only for a few tens of thousands of years before dispersing into the interstellar medium, not many pulsars have been detected while still enclosed in their expanding shell. This is the first clear example of such a pair in the SMC.

This false-color image combines the X-ray view, based on data from XMM-Newton (corresponding to the blue channel), with optical data from NOAO's Cerro Tololo Inter-American Observatory (CTIO), obtained using two special filters that reveal the glow of oxygen (corresponding to the green channel) and hydrogen (corresponding to the red channel).

The bubble-shaped feature is the supernova remnant that encloses the pulsar. The diffuse glow at the center represents X-ray emission from both the pulsar and the hot gas that fills the remnant of the supernova. Other point-like X-ray sources are background, extragalactic objects.

Characterized by a surprisingly slow rotation period of 1062 seconds, this pulsar is located in the Wing of the Small Magellanic Cloud (SMC), a peripheral region of this satellite galaxy of the Milky Way. The Wing is part of the tidal feature that connects the SMC to its neighbor, the Large Magellanic Cloud.

Photo credit: ESA/XMM-Newton/L. Oskinova, University of Potsdam, Germany/M. Guerrero, Instituto de Astrofisica de Andalucia, Spain (X-ray); Cerro Tololo Inter-American Observatory/R. Gruendl & Y. H. Chu, University of Illinois at Urbana-Champaign, USA (optical)

Note: For more information, see Strangely Slow Pulsar Discovered Nestled in Young Supernova Remnant.

Barnard 3 - The Wreath Nebula

NASA's Wide-field Infrared Survey Explorer (WISE) mission presents the "Wreath nebula." Though this isn't the nebula's official name (it's actually called Barnard 3, or IRAS Ring G159.6-18.5), one might picture a wreath in these bright green and red dust clouds -- a ring of evergreens donned with a festive red bow, a jaunty sprig of holly, and silver bells throughout. Interstellar clouds like these are stellar nurseries, places where baby stars are being born.

The green ring (evergreen) is made of tiny particles of warm dust whose composition is very similar to smog found here on Earth. The red cloud (bow) in the middle is probably made of dust that is more metallic and cooler than the surrounding regions. The bright star in the middle of the red cloud, called HD 278942, is so luminous that it is likely what is causing most of the surrounding ring to glow. In fact its powerful stellar winds are what cleared out the surrounding warm dust and created the ring-shaped feature in the first place. The bright greenish-yellow region left of center (holly) is similar to the ring, though more dense. The bluish-white stars (silver bells) scattered throughout are stars located both in front of, and behind, the nebula.

Regions similar to this nebula are found near the band of the Milky Way galaxy in the night sky. The "wreath" is slightly off this band, near the boundary between the constellations of Perseus and Taurus, but at a relatively close distance of only about 1,000 light-years, the cloud is a still part of our Milky Way.

The colors used in this image represent specific wavelengths of infrared light. Blue and cyan (blue-green) represent light emitted at wavelengths of 3.4 and 4.6 microns, which is predominantly from stars. Green and red represent light from 12 and 22 microns, respectively, which is mostly emitted by dust.

Photo credit: NASA/JPL-Caltech/UCLA

Soyuz TMA-03M Approaching the ISS

Filmed from the ISS, the Soyuz TMA-03M spacecraft on its final approach to dock. Andre Kuipers, Oleg Kononenko and Don Pettit launched from Baikonur in Kazakhstan on Wednesday 21 December 2011, and completed 35 orbits of the Earth before eventual docking at the ISS on 23 December 2011. Completing the crew compliment aboard ISS, they will be in orbit for five months.

Photo credit: ESA

Comet Lovejoy Over Paranal Observatory

ESO optician Guillaume Blanchard captured this marvelous wide-angle photo of Comet Lovejoy just two days ago on 22 December 2011. Comet Lovejoy has been the talk of the astronomy community over the past few weeks. It was first discovered on 27 November by the Australian amateur astronomer Terry Lovejoy and was classified as a Kreutz sungrazer, with its orbit taking it very close to the Sun, passing a mere 140,000 kilometers from the Sun’s surface.

Photo credit: G. Blanchard(eso.org/~gblancha)/ESO

Note: For more information, see Christmas Comet Lovejoy Captured at Paranal.

Hard X-Ray All-Sky Map by INTEGRAL/SPI

This image shows the entire sky at hard X-ray energies, between 50 and 100 keV, as observed with the spectrometer on board INTEGRAL (SPI). The image is based on six years worth of data collected with this instrument.

The two main contributions to the emission at these energies are clearly visible: point sources, galactic and extragalactic alike, and diffuse emission. Point sources are scattered across the sky, albeit mainly concentrated along the Galactic Plane; the diffuse emission also traces the Galactic Plane and is fainter, at these energies, than the emission arising from point sources.

In order to study the diffuse emission in great detail and to break it down into the individual physical processes that contribute to it, astronomers need to carefully scrutinize the data and remove the contamination due to point sources.

Photo credit: ESA/INTEGRAL/SPI

Note: For more information, see INTEGRAL Deciphers Diffuse Signature of Cosmic-Ray Electrons.

Galaxy GN-108036

This image shows one of the most distant galaxies known, called GN-108036, dating back to 750 million years after the Big Bang that created our universe. The galaxy's light took 12.9 billion years to reach us.

The galaxy was discovered and confirmed using the Subaru telescope and the W.M. Keck Observatory, respectively, both located atop Mauna Kea in Hawaii. After the galaxy was discovered, astronomers looked at infrared observations of it taken by NASA's Spitzer and Hubble space telescopes, and were surprised by how bright the galaxy appeared. This brightness resulted from an extreme burst of star formation -- a rare event for such an early cosmic era. In fact, GN-108036 is the most luminous galaxy found to date at these great distances.

Astronomers refer to a galaxy's distance by its "redshift," a number that refers to how much the light has been stretched to longer, redder wavelengths by the expansion of the universe. Galaxies with higher redshifts are more distant, and are seen farther back in time. GN-108036 has a redshift of 7.2, making it one of only a handful of galaxies detected this far away and this early in cosmic history.

The callout image above shows a field of galaxies, known as the Great Observatories Origins Deep Survey, or GOODS. A close-up of the Hubble image, and a Spitzer image, are called out at right. In the Spitzer image, infrared light captured by its Infrared Array Camera at wavelengths of 3.6 and 4.5 microns is colored green and red, respectively. In the Hubble image, visible light taken by its Advanced Camera for Surveys instrument at 0.6 and 0.9 microns is blue and green, respectively, while infrared light captured by Hubble's new Wide Field Camera 3 at 1.6 microns is red. GN-108036 is only detected in the infrared, and is completely invisible in the optical Hubble images, explaining its very red color in this picture.

Photo credit: NASA/JPL-Caltech/STScI/University of Tokyo

Closer and Closer to the Vesta Surface

NASA's Dawn spacecraft has spiraled closer and closer to the surface of the giant asteroid Vesta. These images were obtained by Dawn's framing camera in the three phases of its campaign since arriving at Vesta in mid-2011.

The two images on the left represent an identical area, first observed during Dawn's survey orbit (far left image). That orbit aimed to obtain a global characterization of the asteroid. The picture in the center is from Dawn's high-altitude mapping orbit (HAMO) when the surface was systematically imaged during September and October 2011 from an altitude of about 430 miles (700 kilometers) with about 230 feet (70 meters-per-pixel) resolution for global high-resolution stereo image data that were used to develop a global shape model and topographic maps.

Since December 12, 2011, the orbiter has been circling Vesta in a slightly elliptical orbit known as low-altitude mapping orbit (LAMO) at an average 130 miles (210 kilometers) above the asteroid's surface. The image on the right was obtained on December 13 from an altitude of 124 miles (199 kilometers) to the surface and has a resolution of 75 feet (23 meters) per pixel. It covers an area about 12 miles by 12 miles (19 kilometers by 19 kilometers).

The low altitude image has a resolution more than three times better than the resolution from the HAMO phase. There is a lot more detail in the image, like small impact craters or slumping at the steep-flanked mountain in the image center that can be identified in the two images to the left. The center of the LAMO image is at about 45.5 degrees south latitude and 325.1 degrees east longitude.

Photo credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Comparison Between Kepler-20e, Kepler-20f, Venus and the Earth

This chart compares the first Earth-size planets found around a Sun-like star to planets in our own solar system, Earth and Venus. NASA's Kepler mission discovered the newfound planets, called Kepler-20e and Kepler-20f. Kepler-20e is slightly smaller than Venus with a radius .87 times that of Earth. Kepler-20f is a bit larger than Earth at 1.03 times the radius of Earth. Venus is very similar in size to Earth, with a radius of .95 times that our planet.

Prior to this discovery, the smallest known planet orbiting a Sun-like star was Kepler-10b with a radius of 1.42 that of Earth, which translates to 2.9 times the volume.

Both Kepler-20e and Kepler-20f circle in close to their star, called Kepler-20, with orbital periods of 6.1 and 19.6 days, respectively. Astronomers say the two little planets are rocky like Earth but with scorching temperatures.

There are three other larger, likely gaseous planets also know to circle the same star, known as Kepler-20b, Kepler-20c and Kepler-20d.

Illustration credit: NASA/Ames/JPL-Caltech

Note: For more illustrations in this series, see PIA14887: An Unusual Planetary System (Artist's Concept), PIA14888: Kepler-20e -- The Smallest Exoplanet (Artist's Concept), and PIA14889: Kepler-20f -- An Earth-size World (Artist's Concept).

Expedition 30 Soyuz Rolls to the Pad

The Soyuz TMA-03M spacecraft is rolled out by train on its way to the launch pad at the Baikonur Cosmodrome, Kazakhstan, Monday, December 19, 2011. The launch of the Soyuz spacecraft with Expedition 30 Soyuz Commander Oleg Kononenko of Russia, NASA Flight Engineer Don Pettit and European Space Agency astronaut and Flight Engineer Andre Kuipers is scheduled for 8:16 a.m. EST on Wednesday, December 21.

Photo credit: NASA/Carla Cioffi

Update: The Expedition 30 spacecraft launched successfully; a video of the launch can be found here.

Jupiter's Great Red Spot

This Voyager 2 image shows the region of Jupiter extending from the equator to the southern polar latitudes in the neighborhood of the Great Red Spot. A white oval, different from the one observed in a similar position at the time of the Voyager 1 encounter, is situated south of the Great Red Spot. The region of white clouds now extends from east of the red spot and around its northern boundary, preventing small cloud vortices from circling the feature. The disturbed region west of the red spot has also changed since the equivalent Voyager 1 image. It shows more small scale structure and cloud vortices being formed out of the wave structures. The picture was taken on July 3, 1979 from 6 million kilometers (3.72 million miles).

Photo credit: NASA/JPL

Gas Cloud Approaching the Black Hole at the Center of the Milky Way

This simulated view shows a gas cloud (just above center, with its orbit shown in red) that has been observed approaching the supermassive black hole at the center of the Milky Way. This is the first time ever that the approach of such a doomed cloud to a supermassive black hole has been observed and it is expected to break up completely during 2013. The stars orbiting the black hole are also shown along with blue lines marking their orbits. The stars and the cloud are shown in their actual positions in 2011.

Video credit: ESO

Note: For more information, see A Black Hole's Dinner is Fast Approaching.

Comet Lovejoy Grazes the Sun (and Survives)

Comet Lovejoy skimmed across the Sun's edge about 140,000 km above the surface late December 15 and early December 16, 2011, furiously brightening and vaporizing as it approached the Sun. It is the brightest sungrazing comet that SOHO has ever seen, with a nucleus about twice as wide as a football field. It unexpectedly survived the pass and cruised out from behind the Sun some hours later. Comets are ancient balls of dust and ice.

Video credit: NASA; text credit: NASA

Note: For more information, see Comet Lovejoy Plunges into the Sun and Survives.

Sh2-106

This image from the NASA/ESA Hubble Space Telescope shows Sh 2-106, or S106 for short. This is a compact star forming region in the constellation Cygnus (The Swan). A newly-formed star called S106 IR is shrouded in dust at the center of the image, and is responsible for the surrounding gas cloud's hourglass-like shape and the turbulence visible within. Light from glowing hydrogen is colored blue in this image.

Photo credit: NASA/ESA

Note: Another, wide-angle view of Sh2-106 can be found here; for more information, see Young Star Rebels Against its Parent Cloud [heic1118].

NGC 253

The VLT Survey Telescope (VST) has captured in sharp detail the beauty of the nearby spiral galaxy NGC 253. This new portrait is probably the best wide-field view of this object and its surroundings ever taken. It demonstrates that the VST, the newest telescope at ESO's Paranal Observatory, provides broad views of the sky while also offering impressive image quality. Luminous regions of ongoing star formation are spread throughout NGC 253, which is pumping out new stars at a furious pace. The data were processed using the VST-Tube system developed by A. Grado and collaborators at the INAF-Capodimonte Observatory.

Photo credit: ESO/INAF-VST; Acknowledgement: A. Grado/L. Limatola/INAF-Capodimonte Observatory

Note: For more information, see A Galaxy Blooming with New Stars

NGC 2467

Area surrounding the stellar cluster NGC 2467, located in the southern constellation of Puppis ("The Stern"). With an age of a few million years at most, it is a very active stellar nursery, where new stars are born continuously from large clouds of dust and gas. The image, looking like a colorful cosmic ghost or a gigantic celestial Mandrill, contains the open clusters Haffner 18 (center) and Haffner 19 (middle right: it is located inside the smaller pink region — the lower eye of the Mandrill), as well as vast areas of ionized gas. The bright star at the center of the largest pink region on the bottom of the image is HD 64315, a massive young star that is helping shaping the structure of the whole nebular region.

Photo credit: ESO

Messier 83 - The Southern Pinwheel

This spectacular spiral galaxy is known to astronomers as Messier 83. Colloquially, it is also called the Southern Pinwheel due to its similarity to the more northerly Pinwheel galaxy Messier 101. NASA's Spitzer Space Telescope shows us, in spectacular detail, the infrared structure of what many think of as our own Milky Way galaxy's smaller cousin.

Living in the middle of the Milky Way's disk, we see our galaxy only from an obstructed vantage point that is both inside-out and edge-on. We see Messier 83 nearly face-on, giving us a chance to really map out its disk in great detail. This information helps astronomers figure out what our own galaxy would look like if we could warp out to a better vantage point.

Like the Milky Way, Messier 83 is classified as a barred spiral galaxy due to the bar-like pattern of stars that run through its center. This bar region is more interesting in the infrared since we can also see the open "s" shaped curve of dust (red) cutting through the more linear stellar bar (blue-cyan).

This arc of inner dust connects up with the more tightly wound spiral arms in the outer disk, seen here as bright green-red ridges. Between the main spiral arms we also see a complex webbing of dust that permeates the entire disk.

While Messier 83 is about 15 million light years away, it is actually one of the closest barred spiral galaxies in the sky. This gives astronomers an excellent chance to study a galaxy that, although half as big, seems very similar in structure to our own Milky Way galaxy.

Infrared light with wavelengths of 3.6 and 4.5 microns are displayed in blue and green showing primarily the glow from starlight. 8 micron light is rendered in red; the contribution from starlight at 8 microns was subtracted out from the data to better show the dust structures near the galaxy's center.

Photo credit: NASA/JPL-Caltech

Note: A similar version of this photo can be found here.

Rotation of Jupiter

Jupiter observed with the 1 meter telescope at the Pic du Midi observatory and a Basler Scout Camera; images taken between October 10 and October 15, 2011.

Video credit: S2P/IMCCE/OPM/JL Dauvergne/Elie Rousset/Eric Meza/Philippe Tosi/François Colas/Jean Pajus/Xavi Nogués/Emil Kraaikamp

Vampire Star 17 Leporis

This zoom sequence starts with a broad view of the spectacular Milky Way. We close in on the small constellation of Lepus (The Hare), next to the familiar figure of Orion (The Hunter) and focus on the star, SS Leporis, which is faintly visible to the unaided eye. The final stage takes an extraordinarily close look at this unusual double star using the VLT Interferometer at ESO’s Paranal Observatory. These remarkably sharp images — 50 times sharper than those from the NASA/ESA Hubble Space Telescope — not only allow astronomers to watch the two stars in orbit around each other, but also show the larger of the two as a clear disc.

Video credit: ESO/Digitized Sky Survey 2/Nick Risinger (skysurvey.org)/PIONIER/IPAG. Music: John Dyson (from the album Moonwind)

Note: For more information, see Vampire Star Reveals its Secrets.

Supernova Remnant Puppis A

About 3,700 years ago people on Earth would have seen a brand-new bright star in the sky. As it slowly dimmed out of sight, it was eventually forgotten, until modern astronomers found its remains -- called Puppis A. Seen as a red dusty cloud in this image from NASA's Wide-field Infrared Survey Explorer, or WISE, Puppis A is the remnant of a supernova explosion.

Puppis A (pronounced PUP-pis) was formed when a massive star ended its life in an extremely bright and powerful explosion. The expanding shock waves from that explosion are heating up the dust and gas clouds surrounding the supernova, causing them to glow and creating the beautiful red cloud we see here. Much of the material from that original star was violently thrown out into space. However, some of the material remained in an incredibly dense object called a neutron star. This particular neutron star (too faint to be seen in this image) is moving inexplicably fast: over 3 million miles per hour! Astronomers are perplexed over its absurd speed, and have nicknamed the object the "Cosmic Cannonball."

Some of the green-colored gas and dust in the image is from yet another ancient supernova -- the Vela supernova remnant. That explosion happened around 12,000 years ago and was four times closer to us than Puppis A. If you had X-ray vision like the comic book hero Superman, both of these remnants would be among the largest and brightest objects you would see in the sky.

This image was made from observations by all four infrared detectors aboard WISE. Blue and cyan (blue-green) represent infrared light at wavelengths of 3.4 and 4.6 microns, which is primarily from stars, the hottest objects pictured. Green and red represent light at 12 and 22 microns, which is primarily from warm dust.

Photo credit: NASA/JPL-Caltech/UCLA

Is Vesta the "Smallest Terrestrial Planet?"

NASA's Dawn spacecraft spent the last four years voyaging to asteroid Vesta – and may have found a planet.

Vesta was discovered over two hundred years ago but, until Dawn, has been seen only as an indistinct blur and considered little more than a large, rocky body. Now the spacecraft's instruments are revealing the true complexity of this ancient world.

"We're seeing enormous mountains, valleys, hills, cliffs, troughs, ridges, craters of all sizes, and plains," says Chris Russell, Dawn principal investigator from UCLA. "Vesta is not a simple ball of rock. This is a world with a rich geochemical history. It has quite a story to tell!"

In fact, the asteroid is so complex that Russell and members of his team are calling it the "smallest terrestrial planet."

Vesta has an iron core, notes Russell, and its surface features indicate that the asteroid is "differentiated" like the terrestrial planets Earth, Mercury, Mars, and Venus.

Differentiation is what happens when the interior of an active planet gets hot enough to melt, separating its materials into layers. The light material floats to the top while the heavy elements, such as iron and nickel, sink to the center of the planet.

Researchers believe this process also happened to Vesta.

The story begins about 4.57 billion years ago, when the planets of the Solar System started forming from the primordial solar nebula. As Jupiter gathered itself together, its powerful gravity stirred up the material in the asteroid belt so objects there could no longer coalesce. Vesta was in the process of growing into a full-fledged planet when Jupiter interrupted the process.

Although Vesta’s growth was stunted, it is still differentiated like a true planet.

"We believe that the Solar System received an extra slug of radioactive aluminum and iron from a nearby supernova explosion at the time Vesta was forming," explains Russell. "These materials decay and give off heat. As the asteroid was gathering material up into a big ball of rock, it was also trapping the heat inside itself."

As Vesta’s core melted, lighter materials rose to the surface, forming volcanoes and mountains and lava flows.

"We think Vesta had volcanoes and flowing lava at one time, although we've not yet found any ancient volcanoes there," says Russell. "We're still looking. Vesta's plains seem similar to Hawaii's surface, which is basaltic lava solidified after flowing onto the surface.

Vesta has so much in common with the terrestrial planets, should it be formally reclassified from "asteroid" to "dwarf planet"?

"That's up to the International Astronomical Union, but at least on the inside, Vesta is doing all the things a planet does."

If anyone asks Russell, he knows how he would vote.

Text credit: NASA; video credit: NASA

VFTS 102

This is an artist's concept of the fastest rotating star found to date. The massive, bright young star, called VFTS 102 rotates at about two million kilometers per hour. Centrifugal force from this dizzying spin rate has flattened the star into an oblate shape, and spun off a disk of hot plasma, seen edge on in this view from a hypothetical planet. The star may have "spun up" by accreting material from a binary companion star. The rapidly evolving companion later exploded as a supernova. The whirling star lies 160,000 light-years away in the Large Magellanic Cloud, a satellite galaxy of the Milky Way.

Illustration credit: NASA/ESA and G. Bacon (STScI)

Note: For more information and photographs, see VLT Finds Fastest Rotating Star.

Special Note: This is the 500th post here at Ministry of Space Exploration.

Voyager 1 Reaches the Stagnation Region

NASA's Voyager 1 spacecraft has entered a new region between our solar system and interstellar space, which scientists are calling the stagnation region. In the stagnation region, the wind of charged particles streaming out from our Sun has slowed and turned inward for the first time, our solar system's magnetic field has piled up and higher-energy particles from inside our solar system appear to be leaking out into interstellar space. This image shows that the inner edge of the stagnation region is located about 113 astronomical units (10.5 billion miles or 16.9 billion kilometers) from the Sun. Voyager 1 is currently about 119 astronomical units (11 billion miles or 17.8 billion kilometers) from the Sun. The distance to the outer edge is unknown.

Illustration credit: NASA/JPL-Caltech

Kepler-22b

This artist's conception illustrates Kepler-22b, a planet known to comfortably circle in the habitable zone of a Sun-like star. It is the first planet that NASA's Kepler mission has confirmed to orbit in a star's habitable zone -- the region around a star where liquid water, a requirement for life on Earth, could persist. The planet is 2.4 times the size of Earth, making it the smallest yet found to orbit in the middle of the habitable zone of a star like our Sun.

Scientists do not yet know if the planet has a predominantly rocky, gaseous or liquid composition. It's possible that the world would have clouds in its atmosphere, as depicted here in the artist's interpretation.

Illustration credit: NASA/JPL-Caltech/Ames

Note: For more information, see Kepler Confirms First Planet in Habitable Zone of Sun-like Star ; also, PIA14882: Kepler-22b -- Comfortably Circling within the Habitable Zone.

Young Stellar Grouping in Cygnus X

Cygnus X hosts many young stellar groupings. The combined outflows and ultraviolet radiation from the region's numerous massive stars have heated and pushed gas away from the clusters, producing cavities of hot, lower-density gas.

In this 8-micron infrared image, ridges of denser gas mark the boundaries of the cavities. Bright spots within these ridges show where stars are forming today.

Photo credit: NASA/IPAC/MSX

Note: This image was taken by the Midcourse Space Experiment (MSX) and the data processed by Infrared Processing and Analysis Center (IPAC).

Apollo 17 Splashdown

The Apollo 17 spacecraft, containing astronauts Eugene A. Cernan, Ronald E. Evans, and Harrison H. Schmitt, glided to a safe splashdown at 2:25 p.m. EST on December 19, 1972, 648 kilometers (350 nautical miles) southeast of American Samoa.

The astronauts were flown by recovery helicopter to the U.S.S. Ticonderoga slightly less than an hour after the completion of NASA's sixth and last manned lunar landing in the Apollo program.

Photo credit: NASA

Phlegra Montes

Phlegra Montes is a range of gently curving mountains and ridges on Mars. They extend from the northeastern portion of the Elysium volcanic province to the northern lowlands. The High-Resolution Stereo Camera on ESA’s Mars Express collected the data for these images on 1 June 2011 during orbit 9465. This perspective view has been calculated from the Digital Terrain Model derived from the stereo channels.

Photo credit: ESA/DLR/FU Berlin (G. Neukum)

Note: For more information, see Mountains and Buried Ice on Mars.

Southern Enceladus in Radar View

NASA's Cassini spacecraft obtained these views of the south polar area of Saturn's moon Enceladus in visible and near-visible (ultraviolet and infrared) light and synthetic-aperture radar (SAR). The region is south of 45 degrees South latitude. The SAR image, acquired November 6, 2011, is shown as an arc running from upper left to lower right, accented in light blue. Bright and dark edges of this arc are artifacts of the radar imaging process. The background image was taken with visible-light (PIA08342), with color added for emphasis (see below). Visible-light images, like we normally see in photographs, are mostly bright or dark depending on their target's chemical composition, while brightness in SAR images usually depends on how rough or smooth the surface is. The SAR swath is about 15 miles (25 kilometers) wide and is centered at 655 South latitude, 295 West longitude.

The color in the background image is used to separate different materials using ultraviolet, visible and infrared images taken from 2004 to 2009 (see PIA13423). Blue colors represent icy material that originated in the plumes and fell back to the surface. Since these images were taken using illumination by sunlight, they sense ice particles and other roughness in the wavelength range of 50 to 100 microns. The SAR swath uses microwaves 2 centimeters long in wavelength to "light" the surface, so it senses roughness in that range. In addition, the SAR may be seeing that roughness slightly under the surface.

From east-to-west (bottom right to top left), the SAR image crosses near-south-polar terrain close to many of the active sulci, which are long fissures. Throughout the scene, the surface is covered with a network of linear and near-linear grooves and fractures, interpreted to be due to extension, or pulling apart, of Enceladus' crust. These are dominated by a set of larger grooves, about a mile (kilometer) wide, running many tens of miles (kilometers) in length, and smaller grooves about 700 feet (200 meters) wide. A v-shaped region near the lower (eastern) end of the SAR swath, bounded by large faults, appears brighter to radar than most other areas, most likely the result of a rougher surface in the 2-centimeter-wavelength scale. Within, the terrain appears to be slightly more broken up, possibly the result of more dynamic tectonic forces disrupting the surface. The few-miles-wide (few-kilometers-wide) fault bounding the westernmost edge (top) edge of this area looks similar to the four active sulci that run parallel to it, suggesting that it is formed by the same processes; this feature is discussed in PIA15171. A similar fault about 1 to 2 miles (2 to 3 kilometers) wide runs along the center of much of the SAR swath for at least 47 miles (75 kilometers). Farther west still, the swath crosses another v-shaped, SAR-bright region bounded by large faults, including part of the Mosul Sulci system (see PIA15170). Once again, the network of fractures within the bright region appear to be rougher and more broken up. It also coincides with unusually colored terrain surrounding the active sulci (seen in the background images), and so possibly indicates a relatively young or active surface.

Photo credit: NASA/JPL-Caltech/Space Science Institute

Note: For other images in this series, see PIA15170: Enceladus Sparkle and PIA15171: Groovy Enceladus.

Astronaut Testing the SAFER Backpack

Astronaut Mark Lee tests the new backpack called Simplified Aid for EVA Rescue (SAFER), a system designed for use in the event a crew member becomes untethered while conducting an EVA. The Lidar-In-Space Technology Experiment (LITE) is shown in the foreground. The LITE payload employs lidar, which stands for light detection and ranging, a type of optical radar using laser pulses instead of radio waves to study Earth's atmosphere. Unprecedented views were obtained of cloud structures, storm systems, dust clouds, pollutants, forest burning, and surface reflectance. The STS-64 mission marked the first untethered U.S. EVA in 10 years, and was launched on September 9, 1994, aboard the Space Shuttle Orbiter Discovery.

Photo credit: NASA

NGC 104

A color-corrected image of the the second largest and second brightest globular cluster, or tight grouping of stars, seen in Earth's night sky. Called NGC 104 or 47 Tucanae, the light for this image was gathered in 1986 by ESO's 1-m Schmidt Telescope at the La Silla observatory in Chile. The telescope is now decommissioned.

Photo credit: ESO