Artist's Conception of a Protoplanetary Collision

Planets, including those like our own Earth, form from epic collisions between asteroids and even bigger bodies, called proto-planets. Sometimes the colliding bodies are ground to dust, and sometimes they stick together to ultimately form larger, mature planets.

This artist's conception shows one such smash-up, the evidence for which was collected by NASA's Spitzer Space Telescope. Spitzer's infrared vision detected a huge eruption around the star NGC 2547-ID8 between August 2012 and 2013. Scientists think the dust was kicked up by a massive collision between two large asteroids. They say the smashup took place in the star's "terrestrial zone," the region around stars where rocky planets like Earth take shape.

NGC 2547-ID8 is a sun-like star located about 1,200 light-years from Earth in the constellation Vela. It is about 35 million years old, the same age our young sun was when its rocky planets were finally assembled via massive collisions -- including the giant impact on proto-Earth that led to the formation of the moon. The recent impact witnessed by Spitzer may be a sign of similar terrestrial planet building. Near-real-time studies like these help astronomers understand how the chaotic process works.

Illustration credit: NASA/JPL-Caltech

Note: For more information, see PIA18470: Witnessing a Planetary Wreckage and NASA's Spitzer Telescope Witnesses Asteroid Smashup.

Artist's Conception of a Galactic Core Forming

This illustration reveals the celestial fireworks deep inside the crowded core of a developing galaxy, as seen from a hypothetical planetary system consisting of a bright, white star and single planet. The sky is ablaze with the glow from nebulae, fledgling star clusters, and stars exploding as supernovae. The rapidly forming core may eventually become the heart of a mammoth galaxy similar to one of the giant elliptical galaxies seen today.

Image credit: NASA/Space Telescope Science Institute

Note: For more information, see NASA Telescopes Uncover Early Construction of Giant Galaxy and Witnessing the Early Growth of a Giant - First Ever Sighting of Galaxy Core Formation.

Galactic Merger H-ATLAS J142935.3-002836

The Atacama Large Millimeter/submillimeter Array (ALMA) and many other telescopes on the ground and in space have been used to obtain the best view yet of a collision that took place between two galaxies when the Universe was only half its current age. The astronomers enlisted the help of a galaxy-sized magnifying glass to reveal otherwise invisible detail. These new studies of the galaxy H-ATLAS J142935.3-002836 have shown that this complex and distant object looks surprisingly like the well-known local galaxy collision, the Antennae Galaxies.

In this picture you can see the foreground galaxy that is doing the lensing, which resembles how our home galaxy, the Milky Way, would appear if seen edge-on. But around this galaxy there is an almost complete ring — the smeared out image of a star-forming galaxy merger far beyond.

This picture combines the views from the NASA/ESA Hubble Space Telescope and the Keck-II telescope on Hawaii (using adaptive optics).

Image credit: ESO/NASA/ESA/W. M. Keck Observatory

Note: For more information, see Best View Yet of Merging Galaxies in Distant Universe and Best View Yet of Merging Galaxies in Distant Universe.

Comet 67P/Churyumov-Gerasimenko (23 August 2014)

Rosetta navigation camera image taken on 23 August 2014 at about 61 km from 4 km-wide comet 67P/Churyumov-Gerasimenko. From 23 August, Rosetta started taking NAVCAM image sequences as small 2 x 2 rasters, such that roughly one quarter of the comet is seen in the corner of each of the four images, rather than all in just one shot. This is one example of the 512 x 512 pixel ‘corner’ image.

Image credit: ESA/Rosetta/NAVCAM

Flying Through an Aurora

This timelapse was created from photographs taken from on board the International Space Station by the Expedition 40 crew. ESA astronaut Alexander Gerst commented: "We flew right through a massive aurora after last week's solar mass ejection."

Video credit: ESA/NASA

Neptune

During August 16 and 17, 1989, the Voyager 2 narrow-angle camera was used to photograph Neptune almost continuously, recording approximately two and one-half rotations of the planet. These images represent the most complete set of full disk Neptune images that the spacecraft will acquire. This picture from the sequence shows two of the four cloud features which have been tracked by the Voyager cameras during the past two months. The large dark oval near the western limb (the left edge) is at a latitude of 22 degrees south and circuits Neptune every 18.3 hours. The bright clouds immediately to the south and east of this oval are seen to substantially change their appearances in periods as short as four hours. The second dark spot, at 54 degrees south latitude near the terminator (lower right edge), circuits Neptune every 16.1 hours. This image has been processed to enhance the visibility of small features, at some sacrifice of color fidelity.

Image credit: NASA/JPL

Note: For more information, see NASA Pluto-Bound Spacecraft Crosses Neptune's Orbit, 25 Years After Neptune: Reflections on Voyager, and New Horizons Crosses the Orbit of Neptune.

Comet 67P/Churyumov-Gerasimenko: Potential Landing Sites A and C

This annotated image depicts two of the five potential landing sites for the Rosetta mission's Philae lander. The sites (A and C) are located on the larger of the two lobes that make up comet 67P/Churyumov-Gerasimenko.

Five candidate landing sites were identified on Comet 67P/Churyumov-Gerasimenko during the Landing Site Selection Group meeting held August 23 - 24, 2014. The approximate locations of the five regions are marked on these OSIRIS narrow-angle camera images taken on August 16 from a distance of about 62 miles (100 kilometers). The comet nucleus is approximately 2.5 miles (4 kilometers) across. Each elliptical landing site covers six-tenths of a square mile (one square kilometer).

The sites were assigned a letter from an original pre-selection of 10 possible sites identified A through J. The lettering scheme does not signify any ranking. Along with the two sites located on the large lobe, three sites (unseen in this image) are located on the smaller of the comet's two lobes.

Choosing the right landing site is a complex process. That site must balance the technical needs of the orbiter and lander during all phases of the separation, descent, and landing, and during operations on the surface with the scientific requirements of the 10 instruments on board Philae.

Image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Note: For more information, see Rosetta: Landing Site Search Narrows, Philae Candidate Landing Sites, Rosetta: Landing Site Search Narrows, and Candidate Comet Landing Sites Identified.

Comet 67P/Churyumov-Gerasimenko: Potential Landing Sites A, B, I and J

This annotated image depicts four of the five potential landing sites for the Rosetta mission's Philae lander.

Five candidate sites were identified on Comet 67P/Churyumov-Gerasimenko during the Landing Site Selection Group meeting held August 23 - 24, 2014. The approximate locations of the five regions are marked on these OSIRIS narrow-angle camera images taken on August 16 from a distance of about 62 miles (100 kilometers). The comet nucleus is approximately 2.5 miles (4 kilometers) across. Each elliptical landing site covers six-tenths of a square mile (one square kilometer).

The sites were assigned a letter from an original pre-selection of 10 possible sites identified A through J. The lettering scheme does not signify any ranking. Three sites (B, I and J) are located on the smaller of the two lobes of the comet, and two sites (A and C) are located on the larger lobe.

Choosing the right landing site is a complex process. That site must balance the technical needs of the orbiter and lander during all phases of the separation, descent, and landing, and during operations on the surface with the scientific requirements of the 10 instruments on Philae.

Image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Note: For more information, see Rosetta: Landing Site Search Narrows, Philae Candidate Landing Sites, Rosetta: Landing Site Search Narrows, and Candidate Comet Landing Sites Identified.

Comet 67P/Churyumov-Gerasimenko: Potential Landing Sites B and I

This annotated image depicts two of the five potential landing sites for the Rosetta mission's Philae lander. The sites (B and I) are located on the smaller of the two lobes that make up comet 67P/Churyumov-Gerasimenko.

Five candidate landing sites were identified on Comet 67P/Churyumov-Gerasimenko during the Landing Site Selection Group meeting held August 23 - 24, 2014. The approximate locations of the five regions are marked on these OSIRIS narrow-angle camera images taken on August 16 from a distance of about 62 miles (100 kilometers). The comet nucleus is approximately 2.5 miles (4 kilometers) across. Each elliptical landing site covers six-tenths of a square mile (one square kilometer).

The sites were assigned a letter from an original pre-selection of 10 possible sites identified A through J. The lettering scheme does not signify any ranking. Along with the sites B, I and J (unseen in this image) located on the smaller of the two lobes of the comet, two sites (A and C) are located on the larger lobe.

Choosing the right landing site is a complex process. That site must balance the technical needs of the orbiter and lander during all phases of the separation, descent, and landing, and during operations on the surface with the scientific requirements of the 10 instruments on Philae.

Image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Note: For more information, see Rosetta: Landing Site Search Narrows, Philae Candidate Landing Sites, Rosetta: Landing Site Search Narrows, and Candidate Comet Landing Sites Identified.

NGC 4244 - The Silver Needle Galaxy

This stunning new image from the NASA/ESA Hubble Space Telescope shows part of the sky in the constellation of Canes Venatici (The Hunting Dogs).

Although this region of the sky is not home to any stellar heavyweights, being mostly filled with stars of average brightness, it does contain five Messier objects and numerous intriguing galaxies — including NGC 5195, a small barred spiral galaxy considered to be one of the most beautiful galaxies visible, and its nearby interacting partner the Whirlpool Galaxy (heic0506a). The quirky Sunflower Galaxy is another notable galaxy in this constellation, and is one of the largest and brightest edge-on galaxies in our skies.

Joining this host of characters is spiral galaxy NGC 4244, nicknamed the Silver Needle Galaxy, shown here in a new image from Hubble. This galaxy spans some 65,000 light-years and lies around 13.5 million light-years away. It appears as a wafer-thin streak across the sky, with its loosely wound spiral arms hidden from view as we observe the galaxy side on. It is part of a group of galaxies known as the M94 Group [1].

Numerous bright clumps of gas can be seen scattered across its length, along with dark dust lanes surrounding the galaxy’s core. NGC 4244 also has a bright star cluster at its center. Although we can make out the galaxy’s bright central region and star-spattered arms, we cannot see any more intricate structure due to the galaxy’s position; from Earth, we see it stretched out as a flattened streak across the sky.

A number of different observations were pieced together to form this mosaic, and gaps in Hubble’s coverage have been filled in using ground-based data. The Hubble observations were taken as part of the GHOSTS survey, which is scanning nearby galaxies to explore how they and their stars formed to get a more complete view of the history of the Universe.

Image credit: NASA & ESA (Acknowledgement: Roelof de Jong)

Voyager 2 Flyby of Triton

NASA's Voyager 2 spacecraft gave humanity its first glimpse of Neptune and its moon Triton in the summer of 1989. Like an old film, Voyager's historic footage of Triton has been "restored" and used to construct the best-ever global color map of that strange moon (See PIA18668). The map, produced by Dr. Paul Schenk, a scientist at the Lunar and Planetary Institute in Houston, has also been used to make this movie recreating that historic Voyager encounter, which took place 25 years ago, on August 25, 1989.

Video credit: NASA/JPL-Caltech/Lunar & Planetary Institute

Note: For more information, see PIA18668: Map of Triton and Voyager Map Details Neptune's Strange Moon Triton.

Comet 67P/Churyumov-Gerasimenko (21 August 2014)

Full-frame NAVCAM image taken on 21 August 2014 from a distance of about 69 km from comet 67P/Churyumov-Gerasimenko.

Image credit: ESA/Rosetta/NAVCAM

Supernova Remnant Puppis A

The destructive results of a mighty supernova explosion reveal themselves in a delicate blend of infrared and X-ray light, as seen in this image from NASA's Spitzer Space Telescope and Chandra X-Ray Observatory, and the European Space Agency's XMM-Newton.

The bubbly cloud is an irregular shock wave, generated by a supernova that would have been witnessed on Earth 3,700 years ago. The remnant itself, called Puppis A, is around 7,000 light-years away, and the shock wave is about 10 light-years across.

The pastel hues in this image reveal that the infrared and X-ray structures trace each other closely. Warm dust particles are responsible for most of the infrared light wavelengths, assigned red and green colors in this view. Material heated by the supernova's shock wave emits X-rays, which are colored blue. Regions where the infrared and X-ray emissions blend together take on brighter, more pastel tones.

The shock wave appears to light up as it slams into surrounding clouds of dust and gas that fill the interstellar space in this region.

From the infrared glow, astronomers have found a total quantity of dust in the region equal to about a quarter of the mass of our sun. Data collected from Spitzer's infrared spectrograph reveal how the shock wave is breaking apart the fragile dust grains that fill the surrounding space.

Supernova explosions forge the heavy elements that can provide the raw material from which future generations of stars and planets will form. Studying how supernova remnants expand into the galaxy and interact with other material provides critical clues into our own origins.

Infrared data from Spitzer's multiband imaging photometer (MIPS) at wavelengths of 24 and 70 microns are rendered in green and red. X-ray data from XMM-Newton spanning an energy range of 0.3 to 8 kiloelectron volts are shown in blue.

Image credit: NASA/ESA/JPL-Caltech/GSFC/IAFE

Comet 67P/Churyumov-Gerasimenko (20 August 2014)

Rosetta navigation camera image taken on 20 August 2014 at about 83 km from comet 67P/Churyumov-Gerasimenko. The comet nucleus is about 4 km across.

Image credit: ESA/Rosetta/NAVCAM

Releasing Cygnus

Timelapse showing the Orbital Science's Cygnus Orb-2 spacecraft departing from the International Space Station on 15 August 2014.

ESA astronaut Alexander Gerst set up a camera to shoot a series of photographs whilst he and his Expedition 40 colleague NASA's Reid Wiseman operated the Station's robotic arm to maneuver the visiting cargo spacecraft into position for release.

A couple of days later, Cygnus Orb-2 burnt up in Earth's atmosphere during a destructive reentry.

Video credit: ESA/NASA

Comet 67P/Churyumov-Gerasimenko (19 August 2014)

Rosetta navigation camera image taken on 19 August 2014 at about 79 km from comet 67P/Churyumov-Gerasimenko. The comet nucleus is about 4 km across.

Image credit: ESA/Rosetta/NAVCAM

Star Cluster NGC 3603 and Nebula NGC 3576

This mosaic of images from the Wide Field Imager on the MPG/ESO 2.2-meter telescope at ESO’s La Silla Observatory in Chile shows two dramatic star formation regions in the southern Milky Way. The first of these, on the left, is dominated by the star cluster NGC 3603, located about 20,000 light-years away, in the Carina–Sagittarius spiral arm of the Milky Way galaxy. The second object, on the right, is a collection of glowing gas clouds known as NGC 3576 that lies only about half as far from Earth.

Image credit: ESO/G. Beccari

Note: For more information, see A Spectacular Landscape of Star Formation.

Comet 67P/Churyumov-Gerasimenko (18 August 2014)

Rosetta navigation camera image taken on 18 August 2014 at about 84 km from comet 67P/Churyumov-Gerasimenko. The comet nucleus is about 4 km across.

Image credit: ESA/Rosetta/NAVCAM

Mercury Framed by a Coronal Mass Ejection

A Coronal Mass Ejection (CME) from the Sun frames Mercury, as observed by the SOlar Heliospheric Observatory (SOHO) on 13 August 2014.

The shaded blue disc surrounding the Sun at the center is a mask in SOHO’s LASCO instrument that blots out direct sunlight to allow study of the details in the Sun’s corona.

Image credit: SOHO/LASCO C3 (ESA/NASA)

Comet 67P/Churyumov-Gerasimenko (17 August 2014)

Rosetta navigation camera image taken on 17 August 2014 at about 102 km from comet 67P/Churyumov-Gerasimenko. The comet nucleus is about 4 km across.

Image credit: ESA/Rosetta/NAVCAM

Colliding Atmospheres: Mars vs Comet Siding Spring

On October 19, 2014, Comet Siding Spring will pass by Mars only 132,000 km away--which would be like a comet passing about 1/3 of the distance between Earth and the Moon.

The nucleus of the comet won't hit Mars, but there could be a different kind of collision.

"We hope to witness two atmospheres colliding," explains David Brain of the University of Colorado's Laboratory for Atmospheric and Space Physics (LASP). "This is a once in a lifetime event!"

Everyone knows that planets have atmospheres. Lesser known is that comets do, too. The atmosphere of a comet, called its "coma," is made of gas and dust that spew out of the sun-warmed nucleus. The atmosphere of a typical comet is wider than Jupiter.

"It is possible," says Brain, "that the atmosphere of the comet will interact with the atmosphere of Mars. This could lead to some remarkable effects — including Martian auroras."

The timing could scarcely be better. Just last year, NASA launched a spacecraft named MAVEN to study the upper atmosphere of Mars, and it will be arriving in September 2014 barely a month before the comet.

MAVEN is on a mission to solve a longstanding mystery: What happened to the atmosphere of Mars? Billions of years ago, Mars had a substantial atmosphere that blanketed the planet, keeping Mars warm and sustaining liquid water on its surface. Today, only a wispy shroud of CO2 remains, and the planet below is colder and dryer than any desert on Earth. Theories for this planetary catastrophe center on erosion of the atmosphere by solar wind.

"The goal of the MAVEN mission is to understand how external stimuli affect the atmosphere of Mars," says Bruce Jakosky of LASP, MAVEN's principal investigator. "Of course, when we planned the mission, we were thinking about the sun and the solar wind. But Comet Siding Spring represents an opportunity to observe a natural experiment, in which a perturbation is applied and we can see the response."

Brain, who is a member of the MAVEN science team, thinks the comet could spark Martian auroras. Unlike Earth, which has a global magnetic field that shields our entire planet, Mars has a patchwork of "magnetic umbrellas" that sprout out of the surface in hundreds of places all around the planet. If Martian auroras occur, they would appear in the canopies of these magnetic umbrellas.

"That is one thing that we will be looking for with both MAVEN and Hubble Space Telescope," says Brain. "Any auroras we see will not only be neat, but also very useful as a diagnostic tool for how the comet and the Martian atmosphere have interacted."

The atmosphere of the comet includes not only streamers of gas, but also dust and other debris blowing off the nucleus at 56 kilometers per second relative to Mars. At that velocity, even particles as small as half a millimeter across could damage spacecraft. NASA's fleet of Mars orbiters including MAVEN, Mars Odyssey and Mars Reconnaissance Orbiter will maneuver to put the body of Mars between themselves and the comet’s debris during the dustiest part of the encounter.

"It's not yet clear whether any significant dust or gas will hit the Mars atmosphere," cautions Jakosky. "But if it does, it would have the greatest effects on the upper atmosphere."

Meteoroids disintegrating would deposit heat and temporarily alter the chemistry of upper air layers. The mixing of cometary and Martian gases could have further unpredictable effects. Although MAVEN, having just arrived at Mars, will still be in a commissioning phase, it will use its full suite of instruments to monitor the Martian atmosphere for changes.

"By observing both before and after, we hope to determine what effects the comet dust and gas have on Mars, if any," says Jakosky.

Whatever happens, MAVEN will have a ringside seat.

Video credit: NASA

Comet 67P/Churyumov-Gerasimenko (16 August 2014)

Rosetta navigation camera image taken on 16 August 2014 at about 93.5 km from comet 67P/Churyumov-Gerasimenko. The comet nucleus is about 4 km across.

Image credit: ESA/Rosetta/NAVCAM

Stardust Discovers Potential Interstellar Space Particles

The largest interstellar dust track found in the Stardust aerogel collectors was this 35 micron-long hole produced by a 3 picogram speck of dust that was probably traveling so fast that it vaporized upon impact. The other two likely interstellar dust grains were traveling more slowly and remained intact after a soft landing in the aerogel.

Seven rare, microscopic interstellar dust particles that date to the beginnings of the solar system are among the samples collected by scientists who have been studying the payload from NASA's Stardust spacecraft since its return to Earth in 2006. If confirmed, these particles would be the first samples of contemporary interstellar dust.

A team of scientists has been combing through the spacecraft's aerogel and aluminum foil dust collectors since Stardust returned in 2006.The seven particles probably came from outside our solar system, perhaps created in a supernova explosion millions of years ago and altered by exposure to the extreme space environment. The particles would be the first confirmed samples of contemporary interstellar dust.

The research report appears in the August 15 issue of the journal Science. Twelve other papers about the particles will appear next week in the journal Meteoritics & Planetary Science.

"These are the most challenging objects we will ever have in the lab for study, and it is a triumph that we have made as much progress in their analysis as we have," said Michael Zolensky, curator of the Stardust laboratory at NASA's Johnson Space Center in Houston and coauthor of the Science paper.

Stardust was launched in 1999 and returned to Earth on January 15, 2006, at the Utah Test and Training Range, 80 miles west of Salt Lake City. The Stardust Sample Return Canister was transported to a curatorial facility at Johnson where the Stardust collectors remain preserved and protected for scientific study.

Inside the canister, a tennis racket-like sample collector tray captured the particles in silica aerogel as the spacecraft flew within 149 miles (about 240 kilometers) of a comet in January 2004. An opposite side of the tray holds interstellar dust particles captured by the spacecraft during its seven-year, three-billion-mile journey.

Scientists caution that additional tests must be done before they can say definitively that these are pieces of debris from interstellar space. But if they are, the particles could help explain the origin and evolution of interstellar dust.

The particles are much more diverse in terms of chemical composition and structure than scientists expected. The smaller particles differ greatly from the larger ones and appear to have varying histories. Many of the larger particles have been described as having a fluffy structure, similar to a snowflake.

Two particles, each only about two microns (thousandths of a millimeter) in diameter, were isolated after their tracks were discovered by a group of citizen scientists. These volunteers, who call themselves "Dusters," scanned more than a million images as part of a University of California, Berkeley, citizen-science project, which proved critical to finding these needles in a haystack.

A third track, following the direction of the wind during flight, was left by a particle that apparently was moving so fast -- more than 10 miles per second (15 kilometers per second) -- that it vaporized. Volunteers identified tracks left by another 29 particles that were determined to have been kicked out of the spacecraft into the collectors.

Four of the particles reported in Science were found in aluminum foils between tiles on the collector tray. Although the foils were not originally planned as dust collection surfaces, an international team led by physicist Rhonda Stroud of the Naval Research Laboratory searched the foils and identified four pits lined with material composed of elements that fit the profile of interstellar dust particles.

Three of these four particles, just a few tenths of a micron across, contained sulfur compounds, which some astronomers have argued do not occur in interstellar dust. A preliminary examination team plans to continue analysis of the remaining 95 percent of the foils to possibly find enough particles to understand the variety and origins of interstellar dust.

Supernovas, red giants and other evolved stars produce interstellar dust and generate heavy elements like carbon, nitrogen and oxygen necessary for life. Two particles, dubbed Orion and Hylabrook, will undergo further tests to determine their oxygen isotope quantities, which could provide even stronger evidence for their extrasolar origin.

Scientists at Johnson have scanned half the panels at various depths and turned these scans into movies, which were then posted online, where the Dusters could access the footage to search for particle tracks.

Once several Dusters tag a likely track, Andrew Westphal, lead author of the Science article, and his team verify the identifications. In the one million frames scanned so far, each a half-millimeter square, Dusters have found 69 tracks, while Westphal has found two. Thirty-one of these were extracted along with surrounding aerogel by scientists at Johnson and shipped to UC Berkeley to be analyzed.

Image credit: UC Berkeley/Andrew Westphal

Comet 67P/Churyumov-Gerasimenko (15 August 2014)

Rosetta navigation camera image taken on 15 August 2014 at about 91 km from comet 67P/Churyumov-Gerasimenko. The comet nucleus is about 4 km across.

Image credit: ESA/Rosetta/NAVCAM

Surface Variations on Comet 67P/Churyumov-Gerasimenko

This image of comet 67P/Churyumov-Gerasimenko shows the diversity of surface structures on the comet's nucleus. It was taken by the Rosetta spacecraft's navigation camera on August 7, 2014. At the time, the spacecraft was 65 miles (104 kilometers) away from the 2.5 mile (4 kilometer) wide nucleus.

In the image, the comet's head (in the top half of the image) exhibits parallel linear features that resemble 'cliffs', and its neck displays scattered boulders on a relatively smooth, slumping, surface. In comparison, the comet's body (lower half of the image) seems to exhibit a multi-variable terrain, with peaks and valleys, and both smooth and rough topographic features.

Launched in March 2004, Rosetta was reactivated in January 2014 after a record 957 days in hibernation. Composed of an orbiter and lander, Rosetta's objectives upon arrival at comet 67P/Churyumov-Gerasimenko in August are to study the celestial object up close in unprecedented detail, prepare for landing a probe on the comet's nucleus in November, and track its changes as it sweeps past the sun.

Comets are time capsules containing primitive material left over from the epoch when the sun and its planets formed. Rosetta's lander will obtain the first images taken from a comet's surface and will provide the first analysis of a comet's composition by drilling into the surface. Rosetta also will be the first spacecraft to witness at close proximity how a comet changes as it is subjected to the increasing intensity of the sun's radiation. Observations will help scientists learn more about the origin and evolution of our solar system and the role comets may have played in seeding Earth with water, and perhaps even life.

Image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Note: For more information, see As Seen by Rosetta: Comet Surface Variations, Comet on 7 August (b), and Rosetta's Comet in 3D.

SN 2014J in Messier 82

M82 SN2014J: A supernova in the galaxy M82 about 11.4 million light years from Earth.

New Chandra data gives insight into the explosion that produced SN 2014J, one of the closest supernovas discovered in decades. SN 2014J is a so-called Type Ia supernova, an important class that astronomers use to measure the expansion of the Universe. This image shows M82 in the low, medium, and high-energy X-rays that Chandra can detect in red, green, and blue respectively. The boxes in the bottom of the image show close-up views of the region around the supernova in data taken prior to the explosion (left), as well as data gathered about three weeks after the supernova went off (right). The lack of X-rays detected by Chandra rules out one mechanism that scientists theorized could cause the star to explode.

Scale: Image is 12.75 arcmin across (42,000 light years across)

Image credit: NASA/CXC/SAO/R.Margutti et al

Note: For more information, see M82 SN2014J: NASA's Chandra Observatory Searches for Trigger of Nearby Supernova.

Comet 67P/Churyumov-Gerasimenko (14 August 2014)

Rosetta navigation camera image taken on 14 August 2014 at about 100 km from comet 67P/Churyumov-Gerasimenko. The comet nucleus is about 4 km across.

Image credit: ESA/Rosetta/NAVCAM

Comet 67P/Churyumov-Gerasimenko (13 August 2014)

Rosetta navigation camera image taken on 13 August 2014 at about 115 km from comet 67P/Churyumov-Gerasimenko. The comet nucleus is about 4 km across.

Image credit: ESA/Rosetta/NAVCAM

Docking of ATV Georges Lemaître to the International Space Station

Highlights from the docking of ATV Georges Lemaître to the International Space Station. The fifth and final Automated Transfer Vehicle docked with the ISS at 13:30 UTC/15:30 CEST on 12 August 2014. The vehicle is carrying 6602 kg of freight, including 2680 kg of dry cargo and 3921 kg of water, propellants and gases.

Video credit: ESA/NASA

Comet 67P/Churyumov-Gerasimenko (12 August 2014)

Rosetta navigation camera image taken on 12 August 2014 at about 103 km from comet 67P/Churyumov-Gerasimenko. The comet nucleus is about 4 km across.

Image credit: ESA/Rosetta/NAVCAM

Comet 67P/Churyumov-Gerasimenko (11 August 2014)

Rosetta navigation camera image taken on 11 August 2014 at about 102 km from comet 67P/Churyumov-Gerasimenko. The comet nucleus is about 4 km across.

Image credit: ESA/Rosetta/NAVCAM

Supermassive Black Hole

This artist's concept illustrates a supermassive black hole with millions to billions times the mass of our sun. Supermassive black holes are enormously dense objects buried at the hearts of galaxies. (Smaller black holes also exist throughout galaxies.) In this illustration, the supermassive black hole at the center is surrounded by matter flowing onto the black hole in what is termed an accretion disk. This disk forms as the dust and gas in the galaxy falls onto the hole, attracted by its gravity.

Also shown is an outflowing jet of energetic particles, believed to be powered by the black hole's spin. The regions near black holes contain compact sources of high energy X-ray radiation thought, in some scenarios, to originate from the base of these jets. This high energy X-radiation lights up the disk, which reflects it, making the disk a source of X-rays. The reflected light enables astronomers to see how fast matter is swirling in the inner region of the disk, and ultimately to measure the black hole's spin rate.

Illustration credit: NASA/JPL-Caltech

Note: For more information, see NASA's NuSTAR Sees Rare Blurring of Black Hole Light and PIA18467: Big, Spinning Black Hole Blurs Light.

Comet 67P/Churyumov-Gerasimenko from 110 Kilometers

Full-frame NAVCAM image taken on 10 August 2014 from a distance of about 110 km from comet 67P/Churyumov-Gerasimenko. The comet nucleus is about 4 km across.

Image credit: ESA/Rosetta/NAVCAM

Comet 67P/Churyumov-Gerasimenko from 81 Kilometers

Full-frame NAVCAM image taken on 8 August 2014 from a distance of about 81 km from comet 67P/Churyumov-Gerasimenko.

Image credit: ESA/Rosetta/NAVCAM

Comet 67P/Churyumov-Gerasimenko from 83 Kilometers

Full-frame NAVCAM image taken on 7 August 2014 from a distance of about 83 km from comet 67P/Churyumov-Gerasimenko.

Image credit: ESA/Rosetta/NAVCAM

Comet C/2013 A1 Siding Spring and NGC 1316

NASA's NEOWISE mission detected comet C/2013 A1 Siding Spring on July 28, 2014, less than three months before this comet's close flyby of Mars on Oct. 19.

NEOWISE took multiple images of the comet, combined here so that the comet is seen in four different positions relative to the background stars. The image also includes, near the upper right corner, a view of radio galaxy Fornax A (NGC 1316).

NEOWISE previously observed comet Siding Spring on January 16, 2014 (see http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA17833). NEOWISE is part of a team of observation resources to characterize the comet for the encounter with our neighboring planet. At the time of the July 28 observations, the comet was 144 million miles (1.55 astronomical units) from NEOWISE and 175 million miles (1.88 astronomical units) from the Sun. The observations help constrain estimates of dust and gas production as this comet from the outer solar system approaches Mars.

NGC 1316 is a famous radio galaxy, the fourth-brightest radio source in the sky at 1400 megahertz. It is in the Fornax galaxy cluster, which also includes two other galaxies visible in the image. NGC 1316 has an active nucleus, as evidenced by a radio jet and a compact nuclear gas disk. It is thought to be the remnant of a merger between a large elliptical galaxy and a smaller spiral galaxy about 100 million years ago.

Image credit: NASA/JPL-Caltech

Note: For more information, see NASA Mars Spacecraft Prepare for Close Comet Flyby and Orbiter Completes Maneuver to Prepare for Comet Flyby.

Comet 67P/Churyumov-Gerasimenko from 96 Kilometers

Full-frame NAVCAM image taken on 6 August 2014 from a distance of about 96 km from comet 67P/Churyumov-Gerasimenko.

Image credit: ESA/Rosetta/NAVCAM

Comet 67P/Churyumov-Gerasimenko from 145 Kilometers

Full-frame NAVCAM image taken on 5 August 2014 from a distance of about 145 km from comet 67P/Churyumov-Gerasimenko.

Image credit: ESA/Rosetta/NAVCAM

Messier 33 - The Triangulum Galaxy

The VLT Survey Telescope (VST) at ESO’s Paranal Observatory in Chile has captured this beautifully detailed image of the galaxy Messier 33, often called the Triangulum Galaxy. This nearby spiral, the second closest large galaxy to our own galaxy, the Milky Way, is packed with bright star clusters, and clouds of gas and dust. This picture is amongst the most detailed wide-field views of this object ever taken and shows the many glowing red gas clouds in the spiral arms with particular clarity.

Image credit: ESO

Note: For more information, see Triangulum Galaxy Snapped by VST.

Comet 67P/Churyumov-Gerasimenko Detail

Close-up detail of comet 67P/Churyumov-Gerasimenko. The image was taken by Rosetta’s OSIRIS narrow-angle camera and downloaded today, 6 August. The image shows the comet’s ‘head’ at the left of the frame, which is casting shadow onto the ‘neck’ and ‘body’ to the right.

The image was taken from a distance of 120 km and the image resolution is 2.2 meters per pixel.

Image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Comet 67P/Churyumov-Gerasimenko - Detail from the Body's "Base"

Stunning close up detail focusing on a smooth region on the ‘base’ of the ‘body’ section of comet 67P/Churyumov-Gerasimenko. The image was taken by Rosetta’s OSIRIS narrow-angle camera and downloaded today, 6 August. The image clearly shows a range of features, including boulders, craters and steep cliffs.

The image was taken from a distance of 130 km and the image resolution is 2.4 meters per pixel.

Image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Note: For more information, see PIA18642: Rosetta's Target Up Close, Comet on 3 August 2014, and Comet Activity on 2 August 2014.

Comet 67P/Churyumov-Gerasimenko From 285 KM

Comet 67P/Churyumov-Gerasimenko by Rosetta’s OSIRIS narrow-angle camera on 3 August from a distance of 285 km. The image resolution is 5.3 meters/pixel.

Image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Note: Due to the large number of high-quality images and news stories about Comet 67P/Churyumov-Gerasimenko, postings will be done once every six hours instead of the normal one per day for the time being. For more information, see:
* PIA18641: Rosetta's Comet from 177 Miles
* Rosetta Arrives at Target Comet
* Rosetta Arrives at Target Comet
* First Signal Received After Rosetta Arrives at Comet 67P
* Rosetta Arrives at Comet Destination
* Rosetta Arrives at Comet 67P/C-G
* Rosetta Arrival Highlights
* Rosetta at Comet: First Images & Science Results
* Rosetta at Comet: Arrival & Orbit Entry

Comet 67P/Churyumov-Gerasimenko from 234 Kilometers

Full-frame NAVCAM image taken on 4 August 2014 from a distance of about 234 km from comet 67P/Churyumov-Gerasimenko. The image has been processed using an interpolation technique – the factor for scaling up and interpolation is 2. The resolution has therefore been increased from 1024 x 1024 to 2048 x 2048 pixels.

The comet is not centered in the full-frame image as a result of the rendezvous burn conducted the previous day, which adjusted Rosetta's trajectory towards the comet. This effect is corrected for in the commands sent to the spacecraft after the new orbit has been determined.

Image credit: ESA/Rosetta/NAVCAM

Note: For more information, see Comet on 29 July 2014, Comet from 1000 km, Comet on 2 August 2014 - NavCam, and #RosettaAreWeThereYet -- Once upon a time...

Comet 67P/Churyumov-Gerasimenko from 300 Kilometers

Full-frame NAVCAM image taken on 3 August 2014 from a distance of about 300 km from comet 67P/Churyumov-Gerasimenko. The image has been processed using an interpolation technique – the factor for scaling up and interpolation is 2. The resolution has therefore been increased from 1024 x 1024 to 2048 x 2048 pixels. The Sun is towards the bottom of the image in this orientation.

Image credit: ESA/Rosetta/NAVCAM

Note: For more information, see Rosetta Arrives at Comet 67P/C-G - Follow the Event Live.

Three Massive Eruptions on Io

Jupiter's moon Io saw three massive volcanic eruptions within a two-week period last August. This August 29, 2013, outburst on Io was among the largest ever observed on the most volcanically active body in the solar system. The infrared was image taken by Gemini North telescope, courtesy of Katherine de Kleer, UC Berkeley.

Image credit: NSF/NASA/JPL-Caltech//UC Berkeley/Gemini Observatory

Note: For more information, see PIA18656: Eruptions on Io and A Hellacious Two Weeks on Jupiter's Moon Io.

Voyager 1 Entering Interstellar Space

This artist's concept depicts NASA's Voyager 1 spacecraft entering interstellar space, or the space between stars. Interstellar space is dominated by the plasma, or ionized gas, that was ejected by the death of nearby giant stars millions of years ago. The environment inside our solar bubble is dominated by the plasma exhausted by our sun, known as the solar wind.

The interstellar plasma is shown with an orange glow similar to the color seen in visible-light images from NASA's Hubble Space Telescope that show stars in the Orion nebula traveling through interstellar space.

Illustration credit: NASA/JPL-Caltech

Note: For more information, see NASA Voyager Statement About Solar Wind Models and Sun Sends More 'Tsunami Waves' to Voyager 1.

Sunrise at the Comet

Using recent OSIRIS shape models and images, scientists at the Laboratoire d'Astrophysique de Marseille, France, have created this 'trailer' for Rosetta's arrival at comet 67P/Churyumov-Gerasimenko on 6 August.

Video credit: ESA/Rosetta/MPS for OSIRIS Team MSP/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA - Animation: Laboratoire d'Astrophysique de Marseille

Note: For more information, see Amazing New Photo of Rosetta Comet, Rosetta Measures Comet’s Temperature, and Rosetta Takes Comet's Temperature.

Galactic Merger 2MASX J06094582-2140234

From objects as small as Newton's apple to those as large as a galaxy, no physical body is free from the stern bonds of gravity, as evidenced in this stunning picture captured by the Wide Field Camera 3 and Advanced Camera for Surveys onboard the NASA/ESA Hubble Space Telescope.

Here we see two spiral galaxies engaged in a cosmic tug-of-war — but in this contest, there will be no winner. The structures of both objects are slowly distorted to resemble new forms, and in some cases, merge together to form new, super galaxies. This particular fate is similar to that of the Milky Way Galaxy, when it will ultimately merge with our closest galactic partner, the Andromeda Galaxy. There is no need to panic however, as this process takes several hundreds of millions of years.

Not all interacting galaxies result in mergers though. The merger is dependent on the mass of each galaxy, as well as the relative velocities of each body. It is quite possible that the event pictured here, romantically named 2MASX J06094582-2140234, will avoid a merger event altogether, and will merely distort the arms of each spiral without colliding — the cosmic equivalent of a hair ruffling!

These galactic interactions also trigger new regions of star formation in the galaxies involved, causing them to be extremely luminous in the infrared part of the spectrum. For this reason, these types of galaxies are referred to as LIRGs, or Luminous Infrared Galaxies. This image was taken as part of as part of a Hubble survey of the central regions of LIRGs in the local Universe, which also used the NICMOS instrument.

Image credit: ESA/Hubble & NASA

Comet 67P/Churyumov-Gerasimernko from 1210 Miles

This view from the OSIRIS instrument on the European Space Agency's Rosetta spacecraft shows the nucleus of comet 67P/Churyumov-Gerasimernko from a distance of 1,210 miles (1,950 kilometers).

The image was taken on July 29, 2014. One pixel in this image corresponds to approximately 120 feet (37 meters).

The bright neck region between the comet's head and body is becoming increasingly distinct as Rosetta approaches and its view improves.

Image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Note: For more information, see PIA18422: Rosetta's Comet: Imaging the Coma, Catching Up With the Comet's Coma, Comet on 31 July 2014 - NavCam, Comet on 1 August 2014 - NavCam, and Rosetta's Comet: Imaging the Coma. See also #RosettaAreWeThereYet – Fabulous Fables and Tales of Tails and Where are YOU Going?