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Thursday, August 21, 2014

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.

Wednesday, August 20, 2014

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

Tuesday, August 19, 2014

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

Monday, August 18, 2014

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

Sunday, August 17, 2014

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.

Saturday, August 16, 2014

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.

Friday, August 15, 2014

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

Thursday, August 14, 2014

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

Wednesday, August 13, 2014

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.

Tuesday, August 12, 2014

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

Monday, August 11, 2014

Sunday, August 10, 2014

Saturday, August 9, 2014

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.

Friday, August 8, 2014

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.

Thursday, August 7, 2014

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...

Wednesday, August 6, 2014

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.

Tuesday, August 5, 2014

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.

Monday, August 4, 2014

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.

Sunday, August 3, 2014

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.

Saturday, August 2, 2014

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

Friday, August 1, 2014

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?

Thursday, July 31, 2014

Artist’s Impression of Protoplanetary Discs Around Young Stars HK Tauri A and B


This artist’s impression shows a striking pair of wildly misaligned planet-forming gas discs around both the young stars in the binary system HK Tauri. ALMA observations of this system have provided the clearest picture ever of protoplanetary discs in a double star. The new result demonstrates one possible way to explain why so many exoplanets — unlike the planets in the Solar System — came to have strange, eccentric or inclined orbits.

Illustration credit: R. Hurt (NASA/JPL-Caltech/IPAC)

Note: For more information, see ALMA Finds Double Star with Weird and Wild Planet-Forming Discs

Wednesday, July 30, 2014

Messier 33 - The Triangulum Galaxy


The spiral galaxy M33, also known as the Triangulum Galaxy, is one of our closest cosmic neighbors, just three million light-years away. Home to some forty billion stars, it is the third largest in the Local Group of galaxies after the Andromeda Galaxy (M31) and our own Milky Way.

M33 is popular with astrophotographers and from exceptionally dark sites it can even be seen with the naked eye. Thanks to its orientation, we can enjoy a face-on view of the beautiful spiral structure of the galaxy's disc.

This image, from ESA's Herschel space observatory, shows M33 in far-infrared light, revealing the glow of cosmic dust in the interstellar medium that permeates the galaxy. The patchy, disorganized structure of M33's spiral arms resembles a tuft of wool, leading astronomers to classify it as a flocculent spiral galaxy.

The brightest spots sprinkled along the spiral arms are dense pockets of gas and dust where massive stars are born. The most prominent of these is NGC 604, visible in the upper left spiral arm. This is an enormous star-forming region where hundreds of thousands of stars are taking shape.

The image is a composite of the wavelengths: 70 microns (blue), 100 microns (green) and 160 microns (red). At the shortest wavelengths, astronomers trace warmer dust, revealing individual regions of star formation and parent clouds. At longer wavelengths, they detect emission from colder dust, outlining some of the cool dust reservoir along the galaxy’s winding spiral arms. This is where stars may be born in the future.

The image spans about one degree on each side; north is up and east is to the left. The data were collected with Herschel's PACS instrument as part of the Herschel M33 extended survey (HerM33es) Key Programme to study the star formation in the Triangulum Galaxy.

Image credit: ESA/Herschel/PACS/HerM33es Key Programme/C. Kramer/M. Boquien

Tuesday, July 29, 2014

Galaxy Cluster MCS J0416.1-2403


This image from the NASA/ESA Hubble Space Telescope shows the galaxy cluster MCS J0416.1-2403. This is one of six being studied by the Hubble Frontier Fields program. This program seeks to analyze the mass distribution in these huge clusters and to use the gravitational lensing effect of these clusters, to peer even deeper into the distant Universe.

A team of researchers used almost 200 images of distant galaxies, whose light has been bent and magnified by this huge cluster, combined with the depth of Hubble data to measure the total mass of this cluster more precisely than ever before.

Image credit: ESA/Hubble, NASA, HST Frontier Fields
Acknowledgement: Mathilde Jauzac (Durham University, UK and Astrophysics & Cosmology Research Unit, South Africa) and Jean-Paul Kneib (École Polytechnique Fédérale de Lausanne, Switzerland)

Note: For more information, see New Mass Map of a Distant Galaxy Cluster is the Most Precise Yet.

Monday, July 28, 2014

Shape Model of Comet 67P/Churyumov-Gerasimenko


Images of comet 67P/Churyumov-Gerasimenko taken on July 14, 2014, by the OSIRIS imaging system aboard the European Space Agency's Rosetta spacecraft have allowed scientists to create this three-dimensional shape model of the nucleus. The full rotation of the nucleus around its spin axis, shown here, emphasizes the bi-lobate structure already observed with the camera.

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

Note: For more information, see PIA18418: Rosetta Approach Tripych: Comet 67P, Surface Impressions of Rosetta's Comet, Hints of Features, Comet on 20 July 2014, Comet on 23 July 2014 – NavCam Zoom, New Views of the Rosetta Comet, and Comet on 27 July 2014 - NavCam.

Sunday, July 27, 2014

The Halo Around Centaurus A


This image shows the stunning elliptical galaxy Centaurus A. Recently, astronomers have used the NASA/ESA Hubble Space Telescope to probe the outskirts of this galaxy to learn more about its dim halo of stars.

The galaxy's halo of stars has been found to reach much further than expected, extending across 4 degrees in the sky – equivalent to eight times the apparent width of the Moon, or almost twice the width of this image.

This image is a composite of images from Digitized Sky Survey 2 (DSS2), the MPG/ESO 2.2-meter telescope, and the NASA/ESA Hubble Space Telescope's Advanced Camera for Surveys (ACS).

The areas probed by Hubble are identified in the annotated version of this image. Hubble's unique capabilities allowed astronomers to analyze the faint stars in the halo.

Image credit: ESA/Hubble, NASA, Digitized Sky Survey, MPG/ESO; acknowledgement: Davide de Martin

Note: For more information, see Hubble Traces the Halo of a Galaxy More Accurately Than Ever Before and Hubble Traces the Halo of a Galaxy More Accurately Than Ever Before.

Saturday, July 26, 2014

Measuring Kepler-93b


Using data from NASA's Kepler and Spitzer Space Telescopes, scientists have made the most precise measurement ever of the size of a world outside our solar system, as illustrated in this artist's conception. The diameter of the exoplanet, dubbed Kepler-93b, is now known with an uncertainty of just one percent.

According to this new study, the diameter of Kepler-93b is about 11,700 miles (18,800 kilometers), plus or minus 150 miles (240 kilometers) -- the approximate distance between Washington, D.C., and Philadelphia, Pennsylvania. Kepler-93b is 1.481 times the width of Earth, the diameter of which is 7,918 miles (12,742 kilometers).

The results confirm that the exoplanet is a "super-Earth." Although super-Earths are common in the galaxy, none exist in our solar system. Exoplanets like Kepler-93b are therefore our only laboratories to study this major class of planet.

With good limits on super-Earths' sizes as well as their masses, scientists can now start to theorize about what makes up these weird worlds. Previous measurements, by the Keck Observatory in Hawaii, had put Kepler-93b's mass at about 3.8 times that of Earth. The density of Kepler-93b, derived from its mass and newly obtained radius, indicates the planet is in fact very likely made of iron and rock, like Earth.

Despite its newfound similarities in composition to Earth, Kepler-93b is far too hot for life. The exoplanet's orbital distance -- only about one-sixth that of Mercury's from the sun -- implies a scorching surface temperature around 1,400 degrees Fahrenheit (760 degrees Celsius).

The methods employed in the new study could help nail down the sizes of other exoplanets, and improve our understanding of alien worlds.

The Spitzer data for this study was obtained during the "warm mission" phase using its Infrared Array Camera. The lead author of the paper describing these findings is Sarah Ballard, a NASA Carl Sagan Fellow at the University of Washington in Seattle.

Illustration credit: NASA/JPL-Caltech

Note: For more information, see The Most Precise Measurement of an Alien World's Size.

Friday, July 25, 2014

Comet C/2013 UQ4 (Catalina)


Comet C/2013 UQ4 (Catalina) appeared to be a highly active comet one day past perihelion on July 7, 2014.


Image credit: NASA/JPL-Caltech

Note: For more information, see PIA18652: NEOWISE Spots Comet Catalina and NEOWISE Spots a Comet That Looked Like an Asteroid.

Thursday, July 24, 2014

Star Cluster NGC 3293


In this image from the Wide Field Imager on the MPG/ESO 2.2-meter telescope at ESO’s La Silla Observatory in Chile young stars huddle together against a backdrop of clouds of glowing gas and lanes of dust. The star cluster, known as NGC 3293, would have been just a cloud of gas and dust itself about ten million years ago, but as stars began to form it became the bright group we see here. Clusters like this are celestial laboratories that allow astronomers to learn more about how stars evolve.

Image credit: ESO/G. Beccari

Note: For more information, see Lives and Deaths of Sibling Stars.

Wednesday, July 23, 2014

Four Supernova Remnants


In commemoration of the 15th anniversary of NASA's Chandra X-ray Observatory, four newly processed images of supernova remnants dramatically illustrate Chandra's unique ability to explore high-energy processes in the cosmos (see the accompanying press release).

The images of the Tycho and G292.0+1.8 supernova remnants show how Chandra can trace the expanding debris of an exploded star and the associated shock waves that rumble through interstellar space at speeds of millions of miles per hour. The images of the Crab Nebula and 3C58 show how extremely dense, rapidly rotating neutron stars produced when a massive star explodes can create clouds of high-energy particles light years across that glow brightly in X-rays.

Tycho:
More than four centuries after Danish astronomer Tycho Brahe first observed the supernova that bears his name, the supernova remnant it created is now a bright source of X-rays. The supersonic expansion of the exploded star produced a shock wave moving outward into the surrounding interstellar gas, and another, reverse shock wave moving back into the expanding stellar debris. This Chandra image of Tycho reveals the dynamics of the explosion in exquisite detail. The outer shock has produced a rapidly moving shell of extremely high-energy electrons (blue), and the reverse shock has heated the expanding debris to millions of degrees (red and green). There is evidence from the Chandra data that these shock waves may be responsible for some of the cosmic rays - ultra-energetic particles - that pervade the Galaxy and constantly bombard the Earth.

G292.0+1.8:
At a distance of about 20,000 light years, G292.0+1.8 is one of only three supernova remnants in the Milky Way known to contain large amounts of oxygen. These oxygen-rich supernovas are of great interest to astronomers because they are one of the primary sources of the heavy elements (that is, everything other than hydrogen and helium) necessary to form planets and people. The X-ray image from Chandra shows a rapidly expanding, intricately structured, debris field that contains, along with oxygen (yellow and orange), other elements such as magnesium (green) and silicon and sulfur (blue) that were forged in the star before it exploded.

The Crab Nebula:
In 1054 AD, Chinese astronomers and others around the world noticed a new bright object in the sky. This “new star” was, in fact, the supernova explosion that created what is now called the Crab Nebula. At the center of the Crab Nebula is an extremely dense, rapidly rotating neutron star left behind by the explosion. The neutron star, also known as a pulsar, is spewing out a blizzard of high-energy particles, producing the expanding X-ray nebula seen by Chandra. In this new image, lower-energy X-rays from Chandra are red, medium energy X-rays are green, and the highest-energy X-rays are blue.

3C58:
3C58 is the remnant of a supernova observed in the year 1181 AD by Chinese and Japanese astronomers. This new Chandra image shows the center of 3C58, which contains a rapidly spinning neutron star surrounded by a thick ring, or torus, of X-ray emission. The pulsar also has produced jets of X-rays blasting away from it to both the left and right, and extending trillions of miles. These jets are responsible for creating the elaborate web of loops and swirls revealed in the X-ray data. These features, similar to those found in the Crab, are evidence that 3C58 and others like it are capable of generating both swarms of high-energy particles and powerful magnetic fields. In this image, low, medium, and high-energy X-rays detected by Chandra are red, green, and blue respectively.

Image credit: NASA/CXC/SAO

Tuesday, July 22, 2014

Timelapse Video Over Brazil


ESA astronaut Alexander Gerst recorded this timelapse from the International Space Station as it flew over Brazil and the Atlantic Ocean at speeds of 28,800 km/h, 400 km above our planet.

Video credit: ESA