jeudi 9 janvier 2014

Mars Orbiter Images Rover and Tracks in Gale Crater

NASA - Mars Reconnaissance Orbiter (MRO) patch / NASA - Mars Science Laboratory (MSL) patch.

Jan. 9, 2014

Curiosity Trekking, Viewed from Orbit in December 2013 (red arrow)

Image above: NASA's Curiosity Mars rover and tracks left by its driving appear in this portion of a Dec. 11, 2013, observation by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter. The rover is near the lower-left corner of this view. Image Credit: NASA/JPL-Caltech/Univ. of Arizona.

NASA's Curiosity Mars rover and its recent tracks from driving in Gale Crater appear in an image taken by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter on Dec. 11, 2013.

Image above: Curiosity Trekking, Viewed from Orbit in December 2013 (landscape in enhanced color). Image credit: NASA/JPL-Caltech/UA/MSSS.

Excerpts from the large HiRISE observation are at:, showing the rover, and, showing tracks across a landscape in enhanced color.

The tracks show where the rover has zigzagged around obstacles on its route toward the lower slopes of Mount Sharp, its next major destination.

Image above: Curiosity Rover Tracks, Viewed from Orbit in December 2013 - Annotated.  Image credit: NASA/JPL-Caltech/UA/MSSS.

Image above: Two parallel tracks left by the wheels of NASA's Curiosity Mars rover cross rugged ground in this portion of a Dec. 11, 2013, observation by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter. Image Credit: NASA/JPL-Caltech/Univ. of Arizona.

NASA's Mars Reconnaissance Orbiter. Image credit: NASA/JPL-Caltech

HiRISE first imaged the Mars Science Laboratory spacecraft while it was descending on a parachute to place Curiosity on Mars 17 months ago. Since then, it has provided updated views of the rover's traverse, as seen from orbit.

NASA's Mars Science Laboratory "Curiosity". Image credit: NASA/JPL-Caltech

HiRISE is operated by the University of Arizona, Tucson. The instrument was built by Ball Aerospace & Technologies Corp., Boulder, Colo. The Mars Reconnaissance Orbiter project and Mars Science Laboratory project are managed for NASA's Science Mission Directorate, Washington, by NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena.

For more information about HiRISE, see . For more information about the Mars Reconnaissance Orbiter, visit  For more information about Curiosity,  visit

Images (mentioned), Text, Credit: NASA.

Best regards,

New Science, NASA Cargo Launches to Space Station Aboard Orbital-1 Mission

Orbital - Orb-1 Mission patch.

Jan. 9, 2014

Another NASA commercial space partner officially has begun contracted cargo flights to the International Space Station. Dozens of new NASA investigations and other science experiments from across the country are headed to the station aboard Orbital Sciences Corp.'s Cygnus spacecraft as part of the agency's commercial partnerships with U.S. aerospace companies.

Orbital-1 Antares Launch

The launch aboard Orbital's Antares rocket took place from NASA's Wallop's Flight Facility in Virginia Thursday, at 1:07 p.m. EST.

The Orbital-1 mission began the company's first contracted cargo delivery flight to the station through a $1.9 billion NASA Commercial Resupply Services contract. Orbital will fly at least eight cargo missions to the space station through 2016.

U.S. Cargo Ship Launches to ISS on First Resupply Mission

"Today's launch demonstrates how our strategic investments in the American commercial spaceflight industry are helping create new jobs here at home and keep the United States the world leader in space exploration,” NASA Administrator Charles Bolden said. "American astronauts have been living and working continuously in space for the past 13 years on board the International Space Station, and we’re once again sending them supplies launched from U.S. soil. In addition to the supplies, the passion and hard work of many researchers and students are being carried by Cygnus today. I congratulate Orbital and the NASA teams that made this resupply mission possible."

The pressurized Cygnus can accommodate a variety of scientific payloads. The Orbital-1 mission is carrying 2,780 pounds of supplies to the station, not including the weight of packaging materials. This cargo includes vital science experiments, crew provisions, spare parts and other hardware. More than 10,000 students will be involved with 23 experiments they designed. One NASA experiment will study the decreased effectiveness of antibiotics during spaceflight. Another will examine how different fuel samples burn in microgravity, which could inform future design for spacecraft materials.

A portion of the space station had been designated a U.S. National Laboratory, managed by the Center for Advancement of Science in Space (CASIS). CASIS selects and funds new research to use the national lab's unique microgravity environment to conduct experiments not possible on Earth. In one educational experiment selected by CASIS, students will compare how ants' behavior differs in space and on Earth.

The pressurized Cygnus cargo spacecraft

Small, relatively inexpensive satellites collectively referred to as CubeSats will provide a variety of technology demonstrations. They will be launched using the NanoRacks Smallsat Deployment Program from the station’s Japanese Experiment Module (JEM) airlock. The NanoRacks CubeSats will be deployed with the JEM Small Satellite Orbital Deployer.  ArduSat-2 is a CubeSat built and operated by NanoSatisfi of San Francisco, which will help determine potential commercial applications for CubeSat data collection and commercial off-the-shelf electronics. Testing sensors through this mini-satellite format may help lower the cost of applications that use low-Earth observation techniques.

Cygnus will be grappled at 6:02 a.m. Sunday, Jan. 12, by Expedition 38 Flight Engineer Michael Hopkins of NASA, who will use the station's robotic arm to take hold of the spacecraft. Koichi Wakata of the Japan Aerospace Exploration Agency will support Hopkins in a backup position. Wakata will serve as the primary crew member to berth the spacecraft to the  station. NASA's Rick Mastracchio will support him in a backup position. The capsule is scheduled to depart the station in February and burn up during reentry in Earth’s atmosphere.

Orbital Sciences is one of two companies that built and tested new cargo spacecraft under NASA's Commercial Orbital Transportation Services (COTS) program. COTS was completed late last year with an Orbital Sciences demonstration mission to the space station. Space Exploration Technologies (SpaceX), the other company that partnered with NASA under COTS, also is providing commercial resupply services for the agency.

Artist's view of the U.S. Cargo Ship Cygnus arrival to ISS

In addition to cargo flights, NASA's commercial space partners are making progress toward a launch of astronauts from U.S. soil within the next three years.

The International Space Station is a convergence of science, technology and human innovation that demonstrates new technologies and makes research breakthroughs not possible on Earth. The space station has been continuously occupied since November 2000. In that time, it has been visited by more than 200 people and a variety of international and commercial spacecraft. The space station remains the springboard to NASA's next great leap in exploration, including future missions to an asteroid and Mars.

For more information about the Orbital-1 mission and the International Space Station, visit:

Images, Video, Text, Credits: NASA / Bill Ingalls / Orbital.


A galaxy with two hearts

ESA - Hubble Space Telescope patch.

9 January 2014

Hubble view of barred spiral galaxy Messier 83

This new Hubble image shows the spiral galaxy Messier 83, otherwise known as the Southern Pinwheel Galaxy. One of the largest and closest barred spirals to us, this galaxy is dramatic and mysterious; it has hosted a large number of supernova explosions, and is thought to have a double nucleus lurking at its core.

Messier 83 is not one to blend into the background. Located some 15 million light-years away in the constellation of Hydra (The Sea Serpent), it is one of the most conspicuous galaxies of its type in our skies. It is a prominent member of a group of galaxies known as the Centaurus A/M83 Group, which also counts dusty Centaurus A (heic1110) and irregular NGC 5253 (potw1248a) as members.

Hubble and Magellan composite image of Messier 83

Spiral galaxies come in a range of types depending on their appearance and structure — for example, how tightly wound their arms are, and the characteristics of the central bulge. Messier 83 has a "bar" of stars slicing through its centre, leading to its classification as a barred spiral. The Milky Way also belongs to this category.

These bars are thought to act a bit like a funnel, channelling gas inwards towards the galaxy's centre. This gas is then used to form new stars and also to feed the galaxy's central black hole, explaining why many barred spirals — including Messier 83 — have very active and luminous central regions.

Digitized Sky Survey Image of Star Field Around M83 (ground-based image)

However, Messier 83's centre is mysterious and unusual; the supermassive black hole at its heart is not alone. This striking spiral displays a phenomenon known as a double nucleus — a feature that has also been spotted in the Andromeda Galaxy (heic0512), the nearest spiral galaxy to us. This does not mean that Messier 83 contains two central black holes, but that its single supermassive black hole may be ringed by a lopsided disc of stars, which orbits around the black hole and creates the appearance of a dual core [1].

As well as this double nucleus, Messier 83 has hosted quite a few supernova explosions — six in total that we have observed (SN 1923A, SN 1945B, SN 1950B, SN 1957D, SN 1968L, and SN 1983N). This number is matched by only two other galaxies: Messier 61 (potw1324a) which also has six, and NGC 6946 (opo9910e), which tops the list with nine. As well as these explosions, almost 300 supernova remnants — the older leftovers from exploded stars — have been found within Messier 83, detected using the data that make up this image. These observations are being used to study the life cycle of stars. As well as these old remnants, some 3000 star clusters have been identified in Messier 83, some of which are very young at under 5 million years old.

Zooming and panning on barred spiral galaxy Messier 83

This mosaic image uses observations taken by Hubble's Wide Field Camera 3. It shows the galaxy in full, with dark dust lanes, fiery red patches of gas, and bright blue patches of recent star formation speckled across the spiralling arms. Although it looks sprawling, Messier 83 is just under half of the size of the Milky Way.

This new image is being released today, 9 January 2014, at the 223rd meeting of the American Astronomical Society in Washington, DC, USA.


[1] This central region is a very bizarre place. Neither of the two components making up the double nucleus are actually aligned with the galaxies kinematic centre — the region inferred to be the central part of Messier 83 from the motions of the stars within the galaxy. The "second nucleus" is not seen directly, but is detected by studying how mass within the galaxy is distributed.
Notes for editors

The Hubble Space Telescope is a project of international cooperation between ESA and NASA.


NASA release:

Images of Hubble:

Images, Video, Text, Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)
Acknowledgement: William Blair (Johns Hopkins University)/Acknowledgment: W. Blair (STScI/JHU), Carnegie Institution of Washington (Las Campanas Observatory), and NOAO/Palomar/Caltech and UKSTU/AAO / Video: NASA, ESA, and G. Bacon (STScI) / Acknowledgement: William Blair (Johns Hopkins University).


Unravelling the web of a cosmic creeply-crawly

ESA - Hubble Space Telescope logo.

9 January 2014

New Hubble infrared view of the Tarantula Nebula

This new Hubble image is the best-ever view of a cosmic creepy-crawly known as the Tarantula Nebula, a region full of star clusters, glowing gas, and dark dust. Astronomers are exploring and mapping this nebula as part of the Hubble Tarantula Treasury Project, in a bid to try to understand its starry anatomy.

The Tarantula Nebula is located in one of our closest galactic neighbours, the Large Magellanic Cloud. Hubble has released images of this celestial spider several times before: in 2004 (heic0416), 2010 (heic1008), 2011 (heic1105) and 2012 (heic1206). While these images show striking panoramic views of this turbulent region, this new image gives us the deepest and most detailed view yet.

Hubble optical view of the Tarantula Nebula

Created using observations taken as part of the Hubble Tarantula Treasury Project (HTTP), this image is composed of near-infrared observations from both Hubble's Wide Field Camera 3 (WFC3) and Advanced Camera for Surveys (ACS). Due to the combination of infrared filters in this image a purple haze fills the frame, with deep red wisps of dust and bright stars scattered throughout.

This region is an example of an HII region — a large cloud of partially ionised hydrogen within which new stars are being born. Visible to the left of centre is a sparkling star cluster known as R136. It was initially identified as a star, but astronomers puzzled over how one single monstrous star could ionise a giant HII region. However, astronomers later realised it was actually a cluster of stars: a super star cluster.

Comparing optical and infrared Hubble views of the Tarantula Nebula

R136 will eventually become a globular cluster: a spherical ball of old stars that orbits around the centre of its host galaxy. R136 is so massive that it contributes greatly to the Tarantula's brightness, emitting most of the energy that makes the nebula so visible.

The Hubble Tarantula Treasury Project (HTTP) is scanning and imaging many of the stars within the Tarantula, mapping out the locations and properties of the nebula's stellar inhabitants. These observations will help astronomers to view the nebula and piece together an understanding of the nebula's structure [1].

Wide-field view of the Tarantula Nebula and its surroundings (ground-based image)

This new image is being released today, 9 January 2014, at the 223rd meeting of the American Astronomical Society in Washington, DC, USA.


[1] This image of 30 Doradus is also the focal point of an iBook on stellar evolution aimed at children with visual imparments. The book, called "Reach for the Stars: Touch, Look, Listen, Learn" is produced by Elena Sabbi — the lead researcher on this Hubble image — and her collaborators. More information can be found here.
Notes for editors

The Hubble Space Telescope is a project of international cooperation between ESA and NASA.


NASA release:

Images of Hubble:

Images, Text, Credits: NASA, ESA, E. Sabbi (STScI) / Digitized Sky Survey 2. Acknowledgement: Davide De Martin.

Best regards,

What lies beneath? (2)

ESA - SMOS Mission logo / ESA - GOCE Mission logo.

9 January 2014

A field campaign dedicated to SMOS and GOCE has revealed unexpected similarities in the missions’ very different types of measurements. This surprising discovery could lead to a better understanding of what is happening deep under the Antarctic ice sheet.

Around a thousand kilometres from the coast and more than 3000 m above sea level, Dome-C on the Antarctic Plateau is one of the remotest and coldest places on Earth. With very little snowfall it is also extremely dry, effectively a flat white desert.

Different data reveal similar patterns under the ice

Despite being such a harsh environment, these conditions are very stable so it offers an ideal place to check the validity of the data from ESA’s SMOS and GOCE Earth observation satellites.

As such, Daniel Steinhagen from Germany’s Alfred Wegener Institute and Steen Kristensen from the Technical University of Denmark, along with their team, braved the bone-chilling temperatures and ventured out to this wilderness last year to carry out a field campaign for ESA.

SMOS carries an L-band microwave radiometer that captures images of ‘brightness temperature’ to measure soil moisture and ocean salinity. GOCE mapped Earth’s gravity with unrivalled precision for over four years. After more than doubling its planned life in orbit, the GOCE satellite finally ran out of fuel last November. However, its data will continue to be used for many years to come to understand numerous aspects of our planet.

White desert

Based at the isolated Concordia research station at Dome-C, the campaign involved spending two weeks flying a Basler-67 airplane over an area of 350 sq km. The plane carried two key sensors: a radiometer used to record surface microwave emissions to verify SMOS data and a gravity meter.

For SMOS, the natural microwave signals emitted through ice layers and propagating up to the satellite orbiting 700 km above have been shown to be remarkably stable. Therefore, Dome-C represents an ideal reference point to check the health and stability of the SMOS radiometer.

Since it is so remote, no major airborne gravity surveys have been carried out in the area. One of the objectives of the campaign was to fill this gap and support international initiatives to pool airborne gravity measurements across the continent. Also, gravity measurements can be used to verify GOCE’s measurements of local gravity gradients, the bread-and-butter of the mission.

The results of the campaign were presented recently to ESA and included some major surprises.

SMOS and GOCE use completely different types of instrument to measure completely different aspects of Earth. Nevertheless, the measurements taken from the aircraft’s two sensors show the similar patterns across the Antarctic ice surveyed by the plane.

Campaign aircraft

René Forsberg, the gravity expert from the Technical University of Denmark said, “The major, and I must say unexpected, highlight of the campaign was the remarkable similarity between spatial patterns observed by both the gravity and microwave instruments.

“It looks like the SMOS L-band signal contains information from much deeper below the surface than had been previously thought.”

“Although the SMOS mission was originally designed to map soil moisture and ocean salinity across the globe, the results from the campaign could lead to completely new scientific discoveries beneath the Antarctic ice surface using SMOS and unexpected synergies with gravity missions such as GOCE,” added ESA’s Tânia Casal.

Niels Skou from the Technical University Denmark also noted, “I was surprised to see how much and how quickly the microwave brightness temperatures change when flying across the East Antarctic Plateau. These variations, just a few kilometres apart, have never been measured before.

“These results will play an important role in comparing SMOS measurements to those from NASA’s Aquarius and SMAP missions, which make similar measurements.”

Related links:




Images, Text, Credits: ESA / S. Kristensen and F. Forsberg, DTU / IPEV/PNRA / A. Salam / D. Steinhagen / AWI.


mercredi 8 janvier 2014

NASA's Swift Catches X-ray Action at Milky Way's Center

NASA - Swift Mission patch.

Jan. 8, 2014

Swift Sees Changes in the Milky Way 2006 - 2013

Video above: This sequence from the X-ray Telescope aboard NASA’s Swift shows changes in the central region of the Milky Way galaxy from 2006 through 2013. Watch for flares from binary systems containing a neutron star or black hole and the changing brightness of Sgr A* (center), the galaxy’s monster black hole. Image Credit: NASA/Swift/N. Degenaar (Univ. of Michigan).

Recent observations by NASA's Swift spacecraft have provided scientists a unique glimpse into the activity at the center of our galaxy and led to the discovery of a rare celestial entity that may help them test predictions of Albert Einstein's theory of general relativity.

This week, at the annual meeting of the American Astronomical Society in National Harbor, Md., scientists presented their research into images captured by Swift, explaining how these images will help decipher the physical nature of X-ray flares and enabled their discovery of a rare subclass of neutron star.

Image above: This X-ray image of the galactic center merges Swift XRT observations through 2013. Sgr A* is at center. Low-energy X-rays (300 to 1,500 electron volts) are shown in red, medium-energy (1,500 to 3,000 eV) in green, and high-energy (3,000 to 10,000 eV) in blue. The total exposure time is 12.6 days. Image Credit: NASA/Swift/N. Degenaar (Univ. of Michigan).

Swift's seven-year campaign to monitor the center of the Milky Way has doubled the number of images available to scientists of bright X-ray flares occurring at the galaxy's central black hole, dubbed Sagittarius A* (Sgr A*).

Sgr A* sits in the center of the Milky Way's innermost region, 26,000 light-years away in the direction of the constellation Sagittarius. Its mass is at least 4 million times that of the sun. Despite its considerable size, it is not nearly as bright as it could be if it was more active, according to one expert.

"Given its size, this supermassive black hole is about a billion times fainter than it could be," said Nathalie Degenaar, principal investigator on the Swift galactic center campaign and an astronomer at the University of Michigan in Ann Arbor. "Though it's sedate now, it was quite active in the past and still regularly produces brief X-ray flares today."

To better understand the black hole's behavior over time, the Swift team began making regular observations of the Milky Way's center in February 2006. Every few days, the Swift spacecraft turns toward the innermost region of the galaxy and takes a 17-minute-long snapshot with its X-ray Telescope (XRT).

G2 Gas Cloud Simulation

Video above: This simulation shows the future behavior of the G2 gas cloud now approaching Sgr A*, the supermassive black hole at the center of the Milky Way. X-ray emission from the cloud’s tidal interaction with the black hole is expected sometime this spring. Image Credit: ESO/MPE/M.Schartmann.

To date, Swift's XRT has detected six bright flares during which the black hole's X-ray emission was as much as 150 times brighter for a couple of hours. These new detections enabled the team to estimate that similar flares occur every five to 10 days. Scientists will look at differences between the outbursts to decipher their physical nature.

The Swift XRT team expects 2014 to be a banner year for the campaign. A cold gas cloud named G2, about three times the mass of Earth, will pass near Sgr A* and already is being affected by tides from the black hole's powerful gravitational field. Astronomers expect G2 will swing so close to the black hole during the second quarter of the year that it will heat up to the point where it produces X-rays.

If some of the cloud's gas actually reaches Sgr A*, astronomers may witness a significant increase in activity from the black hole. The event will unfold over the next few years, giving scientists a front-row seat to study the phenomena.

"Astronomers around the world are eagerly awaiting the first sign that this interaction has begun," said Jamie Kennea, a team member at Pennsylvania State University in University Park, Pa. "With the invaluable help of Swift, our monitoring program may well provide that indicator."

Scientists saw what they thought was a sign in April, when Swift detected a powerful high-energy burst and a dramatic rise in the X-ray brightness of the Sgr A* region. They were excited to discover the activity came from separate source very near the black hole:  a rare subclass of neutron star.

Image above: Unlabeled image of the X-ray image of the galactic center merges Swift XRT observations through 2013. Image Credit: NASA/Swift/N. Degenaar (Univ. of Michigan).

A neutron star is the crushed core of a star destroyed by a supernova explosion, packing the equivalent mass of a half-million Earths into a sphere no wider than Washington. The neutron star, named SGR J1745-29, is a magnetar, meaning its magnetic field is thousands of times stronger than an average neutron star. Only 26 magnetars have been identified to date.

The discovery of SGR J1745-29 may aid scientists in their exploration of important properties of the Sgr A* black hole. As it spins, the magnetar emits regular X-ray and radio pulses. As it orbits Sgr A*, astronomers could detect subtle changes in the pulse timing because of the black hole's gravitational field, a prediction of Einstein’s theory of general relativity.

"This long-term program has reaped many scientific rewards, and due to a combination of the spacecraft's flexibility and the sensitivity of its XRT, Swift is the only satellite that can carry out such a campaign," said Neil Gehrels, the mission's principal investigator at NASA's Goddard Space Flight Center in Greenbelt, Md.

Goddard manages Swift, which was launched in November 2004. Goddard operates the spacecraft in collaboration with Pennsylvania State University, the Los Alamos National Laboratory in New Mexico and Orbital Sciences Corp. in Dulles, Va. International collaborators are located in the United Kingdom and Italy. The mission includes contributions from Germany and Japan.

For more about the Swift mission, visit:

Related Links:

Downloads from Goddard's Scientific Visualization Studio:

Paper: "The X-Ray Flaring Properties of Sgr A* during Six Years of Monitoring with Swift":

Paper: "Swift Discovery of a New Soft Gamma Repeater, SGR J1745–29, near Sagittarius A*":

Swift Daily Monitoring of the Galactic Center:

The McGill Pulsar Group's Magnetar Catalog:

"NASA's Swift Reveals New Phenomenon in a Neutron Star" (05.29.2013):

Image (mentioned), Videos (mentioned), Text, Credits: NASA / J.D. Harrington / Goddard Space Flight Center / Francis Reddy / Lynn Chandler.


Death By Black Hole In Small Galaxy?

NASA - Chandra X-ray Observatory patch.

Jan. 8, 2014

A bright, long duration flare may be the first recorded event of a black hole destroying a star in a dwarf galaxy. The evidence comes from two independent studies using data from NASA’s Chandra X-ray Observatory and other telescopes.

As part of an ongoing search of Chandra's archival data for events signaling the disruption of stars by massive black holes, astronomers found a prime candidate. Beginning in 1999, an unusually bright X-ray source had appeared in a dwarf galaxy and then faded until it was no longer detected after 2005. 

“We can’t see the star being torn apart by the black hole,” Peter Maksym of the University of Alabama in Tuscaloosa, Ala., who led one of the studies, “but we can track what happens to the star’s remains, and compare it with other, similar events. This one fits the profile of 'death by a black hole.'”

Scientists predict that a star that wanders too close to a giant, or supermassive, black hole could be ripped apart by extreme tidal forces.  As the stellar debris falls toward the black hole, it would produce intense X-radiation as it is heated to millions of degrees. The X-rays would diminish in a characteristic manner as the hot gas spiraled inward.

Image above: A dwarf galaxy is located in the galaxy cluster Abell 1795. Image Credit: X-ray: NASA/CXC/Univ. of Alabama/W.P.Maksym et al & NASA/CXC.

In the past few years, Chandra and other astronomical satellites have identified several suspected cases of a supermassive black hole ripping apart a nearby star. This newly discovered episode of cosmic, black-hole-induced violence is different because it has been associated with a much smaller galaxy than these other cases.

The so-called dwarf galaxy is located in the galaxy cluster Abell 1795, about 800 million light years from Earth. It contains about 700 million stars, far less than a typical galaxy like the Milky Way, which has between 200 and 400 billion stars.

Moreover, the black hole in this dwarf galaxy may be only be a few hundred thousand times as massive as the sun, making it ten times less massive than the galaxy's supermassive black hole, and placing it in what astronomers call an “intermediate mass black hole” category.

“Scientists have been searching for these intermediate mass black holes for decades,” said Davide Donato of NASA’s Goddard Space Flight Center (GSFC) in Greenbelt, Md., who led a separate team of researchers. “We have lots of evidence for small black holes and very big ones, but these medium-sized ones have been tough to pin down.”

A Tour of Galaxy Cluster Abell 1795

The evidence for a star being ripped apart by the dwarf galaxy’s black hole came from combing through Chandra data that had been taken over several years. Because Abell 1795 is a target that Chandra observes regularly to help calibrate its instruments, the researchers had access to an unusually large reservoir of data on this object.

“We are very lucky that we had so much data on Abell 1795 over such a long period of time,” said Donato’s co-author Brad Cenko, also of GSFC. “Without that, we could never have uncovered this special event.”

The dwarf galaxy’s location in a galaxy cluster also makes it a potential victim of another type of cosmic violence. Because galaxy clusters are crowded with galaxies, it’s possible that a large number of stars have been pulled away from the dwarf galaxy by gravitational interactions with another galaxy in the past, a process called tidal stripping.

“It looks like the stars in this galaxy not only need to worry about the black hole in the center,” said Makysm’s co-author Melville Ulmer of Northwestern University in Evanston, Ill. “They might also be stolen away on the outside by gravity from a passing galaxy.”

Astronomers believe that intermediate mass black holes may be the “seeds” that ultimately formed the supermassive black holes in the centers of galaxies like the Milky Way. Finding additional nearby examples should teach us about how these primordial galaxies from the early universe grew and evolved over cosmic time.

Chandra X-ray Observatory. Image Credit: NASA/CXC

Some of the additional clues to this star attack came from NASA’s Extreme Ultraviolet Explorer that picked up a very bright ultraviolet source in 1998, which could have marked a time just after the star was initially torn apart. A flare in X-rays may have also been detected with ESA’s XMM-Newton satellite in 2000.

Peter Maksym presented these results today at the 223rd meeting of the American Astronomical Society meeting in Washington, DC on behalf of his team. A paper describing their work is available online and was published in the November 1st, 2013 issue of the Monthly Notices of the Royal Astronomical Society. The paper by Davide Donato and his colleagues on this same event is available online and was accepted for publication in The Astrophysical Journal.

NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory in Cambridge, Mass., controls Chandra's science and flight operations.

For Chandra images, multimedia and related materials, visit:

For an additional interactive image, podcast, and video on the finding, visit:

Images (mentioned), Video, Text, Credits: NASA / Marshall Space Flight Center / Janet Anderson / Chandra X-ray Center / Megan Watzke.


Gaia enters its operational orbit

ESA - Gaia Mission patch.

08 January 2014

ESA's billion-star surveyor Gaia is now in its operational orbit around a gravitationally stable virtual point in space called 'L2', 1.5 million km from Earth.

Gaia liftoff. Credit: ESA / S. Corvaja

Gaia has been travelling towards L2 since 19 December, when, just before dawn local time, it was spectacularly launched from ESA's Spaceport in Kourou, French Guiana.

A day later, Gaia performed an important thruster burn to set course to its destination. Last night, a critical manoeuvre boosted into its 263 000 × 707 000 × 370 000 km, 180 day-long orbit around L2. A small course correction will be made next week to complete the manoeuvre.

"Entering orbit around L2 is a rather complex endeavour, achieved by firing Gaia's thrusters in such a way as to push the spacecraft in the desired direction whilst keeping the Sun away from the delicate science instruments," describes David Milligan, Gaia spacecraft operations manager.

Gaia: launch to orbit. Credit: ESA / C. Carreau/ ATG medialab

"After a beautiful launch from Kourou last month, we are very happy to now have reached our destination, and we are looking forward to starting our science operations in the coming months," says Giuseppe Sarri, ESA's Gaia project manager.

Once the spacecraft instruments have been fully tested and calibrated – an activity that started en route to L2 and will continue for another four months – Gaia will be ready to enter a five-year operational phase.

Gaia will make very accurate observations of one billion stars, charting their precise positions and motions, as well as their temperatures, luminosities and compositions.

This enormous census will result in the most accurate 3D map yet of the Milky Way and allow astronomers to determine the origin and the evolution of our galaxy.

Inside Gaia's billion-pixel camera. Credit: ESA / C. Carreau

To achieve its goal, Gaia will spin slowly, sweeping its two telescopes across the entire sky and focusing their light simultaneously onto a single digital camera – the largest ever flown in space with nearly a billion pixels.

Gaia will observe each star an average of 70 times over the five-year mission, after which the data archive will exceed one million Gigabytes, equivalent to about 200 000 DVDs' worth of data.

The task of processing and analysing this colossal treasure trove of data will fall to the Gaia Data Processing and Analysis Consortium, comprising more than 400 individuals at scientific institutes across Europe.

"Our Gaia discovery machine will keep us busy throughout the mission, with the final results coming only after the five years of data have been analysed. But it will be well worth the wait, ultimately giving us a new view of our cosmic neighbourhood and its history," says Timo Prusti, ESA's Gaia project scientist.

Related Links:

Watch a replay of the Gaia launch:

Webcast replay 19 December:',800,600)%29&farchive_objecttypeid=18&farchive_objectid=30912

Images (mentioned), Videos (mentioned), Text, Credit: ESA.

Best regards,

Stormy Stars? NASA's Spitzer Probes Weather on Brown Dwarfs

NASA - Spitzer Space Telescope patch.

January 8, 2014

This Just In: Storms Expected on Brown Dwarfs

Image above: This artist's concept shows what the weather might look like on cool star-like bodies known as brown dwarfs. These giant balls of gas start out life like stars, but lack the mass to sustain nuclear fusion at their cores, and instead, fade and cool with time. Image credit: NASA/JPL-Caltech/University of Western Ontario/Stony Brook University.

Swirling, stormy clouds may be ever-present on cool celestial orbs called brown dwarfs. New observations from NASA's Spitzer Space Telescope suggest that most brown dwarfs are roiling with one or more planet-size storms akin to Jupiter's "Great Red Spot."

"As the brown dwarfs spin on their axis, the alternation of what we think are cloud-free and cloudy regions produces a periodic brightness variation that we can observe," said Stanimir Metchev of the University of Western Ontario, Canada. "These are signs of patchiness in the cloud cover."

Metchev is principal investigator of the brown dwarf research. The results were presented at a news conference today at the 223rd annual meeting of the American Astronomical Society in Washington by Metchev's colleague, Aren Heinze, of Stony Brook University, New York.

Brown dwarfs form as stars do, but lack the mass to fuse atoms continually and blossom into full-fledged stars. They are, in some ways, the massive kin to Jupiter.

Scientists think that the cloudy regions on brown dwarfs take the form of torrential storms, accompanied by winds and, possibly, lightning more violent than that at Jupiter or any other planet in our solar system. However, the brown dwarfs studied so far are too hot for water rain; instead, astronomers believe the rain in these storms, like the clouds themselves, is made of hot sand, molten iron or salts.

In a Spitzer program named "Weather on Other Worlds," astronomers used the infrared space telescope to watch 44 brown dwarfs as they rotated on their axis for up to 20 hours. Previous results had suggested that some brown dwarfs have turbulent weather, so the scientists had expected to see a small fraction vary in brightness over time. However, to their surprise, half of the brown dwarfs showed the variations. When you take into account that half of the objects would be oriented in such a way that their storms would be either hidden or always in view and unchanging, the results indicate that most, if not all, brown dwarfs are racked by storms.

"We needed Spitzer to do this," said Metchev. "Spitzer is in space, above the thermal glow of the Earth's atmosphere, and it has the sensitivity required to see variations in the brown dwarfs' brightness."

Spitzer Space Telescope. mage credit: NASA/JPL-Caltech

The results led to another surprise as well. Some of the brown dwarfs rotated much more slowly than any previously measured, a finding that could not have been possible without Spitzer's long, uninterrupted observations from space. Astronomers had thought that brown dwarfs sped up to very fast rotations when they formed and contracted, and that this rotation didn't wind down with age.

"We don't yet know why these particular brown dwarfs spin so slowly, but several interesting possibilities exist," said Heinze.  "A brown dwarf that rotates slowly may have formed in an unusual way -- or it may even have been slowed down by the gravity of a yet-undiscovered planet in a close orbit around it."

The work may lead to a better understanding of not just brown dwarfs but their "little brothers": the gas-giant planets. Researchers say that studying the weather on brown dwarfs will open new windows onto weather on planets outside our solar system, which are harder to study under the glare of their stars. Brown dwarfs are weather laboratories for planets, and, according to the new results, those laboratories are everywhere.

Other researchers on the team include: Daniel Apai and Davin Flateau of the University of Arizona, Tucson; Mark Marley of NASA Ames Research Center, Moffett Field; Jacqueline Radigan of the Space Telescope Science Institute, Baltimore, Md.; Etienne Artigau of Universite de Montreal, Canada; Adam Burgasser of University of California San Diego; Peter Plavchan of NASA's Exoplanet Science Institute at the California Institute of Technology, Pasadena; and Bertrand Goldman of Max-Planck Institute for Astronomy, Germany.

NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. Spacecraft operations are based at Lockheed Martin Space Systems Company, Littleton, Colorado. Data are archived at the Infrared Science Archive housed at the Infrared Processing and Analysis Center at Caltech. Caltech manages JPL for NASA.For more information about Spitzer, visit and

Images (mentioned), Text, Credits: NASA / JPL / Whitney Clavin.


mardi 7 janvier 2014

Powerful Planet Finder Turns Its Eye to the Sky

Gemini Observatory logo.

Jan. 7, 2014

Image above: This image taken by the Gemini Planet Imager (GPI) shows a planet orbiting the star Beta Pictoris. In addition to the image, the GPI obtains spectral information from every pixel element in the field of view, allowing scientists to study the planet in great detail. Image Credit: Gemini/Christian Marois, NRC Canada.

After nearly a decade of development, construction and testing, the world’s most advanced instrument for directly imaging and analyzing planets around other stars is pointing skyward and collecting light from distant worlds.

The instrument, called the Gemini Planet Imager (GPI), was designed, built, and optimized for imaging giant planets next to bright stars, in addition to studying dusty disks around young stars. It is the most advanced instrument of its kind to be deployed on one of the world’s biggest telescopes – the 26-foot (8-meter) Gemini South telescope in Chile.

Image above: Gemini Planet Imager’s first light image of the light scattered by a disk of dust orbiting the young star HR4796A. This narrow ring is thought to be dust from asteroids or comets left behind by planet formation; some scientists have theorized that the sharp edge of the ring is defined by an unseen planet. The left image (1.9-2.1 microns) shows normal light, including both the dust ring and the residual light from the central star scattered by turbulence in the Earth’s atmosphere. The right image shows only polarized light. Leftover starlight is unpolarized and hence removed from this image. The light from the back edge of the disk is strongly polarized as it scatters towards us. Image credit: Processing by Marshall Perrin, Space Telescope Science Institute.

Imaging a planet next to a star is a tricky task. The planet is much fainter than its star, and also appears very close. These challenges make the act of separating the planet's light from the glare of the star difficult. NASA’s Jet Propulsion Laboratory in Pasadena, Calif., contributed to the project by designing and building an ultra-precise infrared sensor to measure small distortions in starlight that might mask a planet.

“Our tasks were two-fold,” said Kent Wallace, JPL’s subsystem technical lead for the project. “First, keep the star centered on the instrument so that its glare is blocked as much as possible. Second, ensure the instrument itself is stable during the very long exposures required to image faint companions.”

Image above: Comparison of Europa observed with Gemini Planet Imager in K1 band on the right and visible albedo visualization based on a composite map made from Galileo SSI and Voyager 1 and 2 data (from USGS) on the left. While GPI is not designed for ‘extended’ objects like this, its observations could help in following surface alterations on icy satellites of Jupiter or atmospheric phenomena (e.g. clouds, haze) on Saturn’s moon Titan. The GPI near-infrared color image is a combination of 3 wavelength channels. Image credit: Processing by Marshall Perrin, Space Telescope Science Institute and Franck Marchis SETI Institute.

GPI detects infrared, or heat, radiation from young Jupiter-like planets in wide orbits around other stars. Those are equivalent to the giant planets in our own solar system not long after their formation. Every planet GPI sees can be studied in detail, revealing components of their atmospheres.

Although GPI was designed to look at distant planets, it can also observe objects in our solar system. Test images of Jupiter’s moon Europa, for example, can allow scientists to map changes in the satellite’s surface composition. The images were released today at the 223rd meeting of the American Astronomical Society in Washington.

Read the full news release from Gemini Observatory at

Images (mentioned), Text, Credits: NASA / JPL / Whitney Clavin.


Recently Reactivated NASA Spacecraft Spots Its First New Asteroid

NASA - NEO WISE Mission logo.

Jan. 7, 2014

Image above: The six red dots in this composite picture indicate the location of the first new near-Earth asteroid seen by NASA's Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE). Image Credit: NASA.

NASA's Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) spacecraft has spotted a never-before-seen asteroid -- its first such discovery since coming out of hibernation last year.

NEOWISE originally was called the Wide-field Infrared Survey Explorer (WISE), which had made the most comprehensive survey to date of asteroids and comets. The spacecraft was shut down in 2011 after its primary mission was completed. But in September 2013, it was reactivated, renamed and given a new mission, which is to assist NASA's efforts to identify the population of potentially hazardous near-Earth objects (NEOs). NEOWISE also can assist in characterizing previously detected asteroids that could be considered potential targets for future exploration missions.

NEOWISE's first discovery of its renewed mission came on Dec. 29 -- a near-Earth asteroid designated 2013 YP139. The mission's sophisticated software picked out the moving object against a background of stationary stars. As NEOWISE circled Earth scanning the sky, it observed the asteroid several times over half a day before the object moved beyond its view. Researchers at the University of Arizona used the Spacewatch telescope at the Kitt Peak National Observatory southwest of Tucson to confirm the discovery. Peter Birtwhistle, an amateur astronomer at the Great Shefford Observatory in West Berkshire, England, also contributed follow-up observations. NASA expects 2013 YP139 will be the first of hundreds of asteroid discoveries for NEOWISE.

"We are delighted to get back to finding and characterizing asteroids and comets, especially those that come into Earth’s neighborhood," said Amy Mainzer, the mission's principal investigator from NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif. "With our infrared sensors that detect heat, we can learn about their sizes and reflectiveness."

2013 YP139 is about 27 million miles (43 million kilometers) from Earth. Based on its infrared brightness, scientists estimate it to be roughly 0.4 miles (650 meters) in diameter and extremely dark, like a piece of coal. The asteroid circles the sun in an elliptical orbit tilted to the plane of our solar system and is classified as potentially hazardous. It is possible for its orbit to bring it as close as 300,000 miles from Earth, a little more than the distance to the moon. However, it will not come that close within the next century.

WISE discovered more than 34,000 asteroids and characterized 158,000 throughout the solar system during its prime mission in 2010 and early 2011. Its reactivation in September followed 31 months in hibernation.

WISE Reactivated to Hunt for Asteroids. Image Credit: NASA

NEOWISE will continue to detect asteroids and comets. The observations will be automatically sent to the clearinghouse for solar system bodies, the Minor Planet Center in Cambridge, Mass., for comparison against the known catalog of solar system objects and to determine orbit if the object is not known. A community of professional and amateur astronomers will provide follow-up observations, establishing firm orbits for the previously unseen objects.   Infrared sensors, similar to the cameras on NEOWISE, are a powerful tool for discovering, cataloging and understanding the asteroid population. Some of the objects about which NEOWISE will be collecting data could become candidates for NASA's announced asteroid initiative, which will be the first mission to identify, capture and relocate an asteroid for astronauts to explore. The initiative represents an unprecedented technological feat that will lead to new scientific discoveries and technological capabilities that will help protect our home planet and achieve the goal of sending humans to an asteroid by 2025.

JPL manages the project for NASA's Science Mission Directorate in Washington. The Space Dynamics Laboratory in Logan, Utah, built the science instrument. Ball Aerospace & Technologies Corp. of Boulder, Colo., built the spacecraft. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA.

An image of asteroid 2013 YP139, taken by NEOWISE, is available at:

More information about NEOWISE is available online at:

Images (mentioned). Text, Credits: NASA / Dwayne Brown / JPL / DC Agle.

Best regards,

Pandora's magnifying glass

ESA Hubble Space Telescope logo.

7 January 2014

First image from Hubble's Frontier Fields

Hubble Frontier Fields view of Abell 2744

This image of Abell 2744 is the first to come from Hubble's Frontier Fields observing programme, which is using the magnifying power of enormous galaxy clusters to peer deep into the distant Universe. Abell 2744, nicknamed Pandora's Cluster, is thought to have a very violent history, having formed from a cosmic pile-up of multiple galaxy clusters.

Astronomers previously observed Abell 2744 with the NASA/ESA Hubble Space Telescope back in 2011, exploring the cluster's history. They found that at least four galaxy clusters had crashed into one another to form Abell 2744, causing some weird and wonderful effects. This mix of cosmic phenomena, some of which had never been seen before, led to the nickname of Pandora's Cluster (heic1111).

A mix of hazy elliptical galaxies and colourful spirals can be seen clumping together in the centre of this image. The effects of the cluster's gravity can be seen in the blue arcs and distorted shapes that are scattered across the frame, including galaxies that seem to be bleeding into the surrounding space. The arcs are actually the distorted images of galaxies far in the distance.

Abell 2744 is the first of six targets for an observing programme known as Frontier Fields. This three-year, 840-orbit programme [1] will yield our deepest views of the Universe to date, using the power of Hubble to explore more distant regions of space than could otherwise be seen, by observing gravitational lensing effects around six different galaxy clusters.

Gravitational lensing is a phenomenon caused by an object's influence on the space-time around it. Massive objects like galaxy clusters [2] warp and distort this space-time. This causes light from more distant objects hidden behind this makeshift lens to be deflected and bent, leading to a bizarre array of optical effects — for example, it caused a cosmic space invader to appear around cluster Abell 68 (heic1304) by creating mirror images of one galaxy, as well as smearing galaxies out into arcs, and creating multiple images of individual objects.

Hubble Space Telescope

As well as creating these weird shapes, lensing also magnifies the images so that astronomers can see more detail. This means that distant objects that otherwise would be too distant and faint to be seen become visible — something that Frontier Fields aims to exploit over the coming years.

Some results from this programme are already starting to emerge, with Abell 2744 as the first target. In a new paper submitted to The Astrophysical Journal on 29 November 2013 (available on the ArXiv Preprint Server), a group of astronomers detected a large number of distant, gravitationally lensed galaxy candidates — all viewed through Abell 2744, with the galaxy cluster acting as a lens. They also found that five of these candidates are part of distant systems that appear to have been imaged multiple times due to the cluster's gravitational lensing effects. These deep surveys using massive galaxy clusters like Abell 2744 show that looking through cosmic lenses can be an effective and useful way to study the distant Universe. For more information on gravitational lensing see Hubblecast 70: Peering around cosmic corners.

This image is part of the first set of super-deep views of the Universe obtained by the Frontier Fields observing program, and is being released today, 7 January 2014, at the 223rd meeting of the American Astronomical Society in Washington, DC, USA.


[1] A typical Hubble observing programme lasts from a few to a few tens of orbits.

[2] All objects that have mass affect the space around them in this way, but huge clumps of mass like galaxy clusters do so more strongly.

Notes for editors:

The Hubble Space Telescope is a project of international cooperation between ESA and NASA.


ESA/Hubble Science Announcement: Start of Hubble Frontier Fields observations:

ArXiv Preprint Server:

Hubblecast 70: Peering around cosmic corners:

ESA Hubble site:

Image, Text, Credits: NASA, ESA, and J. Lotz, M. Mountain, A. Koekemoer, and the HFF Team (STScI).


SpaceX Successfully Launches THAICOM 6 Satellite to Geostationary Transfer Orbit

SpaceX - Falcon 9 / THAICOM 6 Satellite launch patch.

Jan. 7, 2014

Falcon 9 rocket launch THAICOM 6 Satellite

THAICOM 6 mission marks second successful GTO flight for the upgraded Falcon 9 launch vehicle

Cape Canaveral Air Force Station, Florida – Today, Space Exploration Technologies (SpaceX) successfully launched the THAICOM 6 satellite for leading Asian satellite operator THAICOM.  Falcon 9 delivered THAICOM 6 to its targeted 295 x 90,000 km geosynchronous transfer orbit at 22.5 degrees inclination.  The Falcon 9 launch vehicle performed as expected, meeting 100% of mission objectives.

SpaceX Launch of Thaicom-6 on Falcon 9v1.1 Rocket

Falcon 9 lifted off from Space Launch Complex 40 (SLC-40) at 5:06 PM Eastern Time.  Approximately 184 seconds into flight, Falcon 9’s second stage’s single Merlin vacuum engine ignited to begin a five minute, 35 second burn that delivered the THAICOM 6 satellite into its parking orbit. Eighteen minutes after injection into the parking orbit, the second stage engine relit for just over one minute to carry the THAICOM 6 satellite to its final geostationary transfer orbit.  The restart of the Falcon 9 second stage is a requirement for all geostationary transfer missions.

THAICOM 6 satellite

“Today’s successful launch of the THAICOM 6 satellite marks the eighth successful flight in a row for Falcon 9,” said Gwynne Shotwell, President of SpaceX. “SpaceX greatly appreciates THAICOM’s support throughout this campaign and we look forward to a busy launch schedule in 2014.”  

The THAICOM 6 mission marks Falcon 9’s second flight to a geosynchronous transfer orbit and begins a regular cadence of launches planned for SpaceX in 2014. SpaceX has nearly 50 launches on manifest, of which over 60% are for commercial customers.

THAICOM 6 satellite mission description

This launch also marks the third of three qualification flights needed to certify the Falcon 9 to fly missions under the Evolved Expendable Launch Vehicle (EELV) program. Once Falcon 9 is certified, SpaceX will be eligible to compete to launch national security satellites for the U.S. Air Force.

About SpaceX:

SpaceX designs, manufactures, and launches the world's most advanced rockets and spacecraft. The company was founded in 2002 by Elon Musk to revolutionize space transportation, with the ultimate goal of enabling people to live on other planets. Today, SpaceX is advancing the boundaries of space technology through its Falcon launch vehicles and Dragon spacecraft. SpaceX is a private company owned by management and employees, with minority investments from Founders Fund, Draper Fisher Jurvetson, and Valor Equity Partners. The company has more than 3,000 employees in California, Texas, Washington, D.C., and Florida. For more information, visit

Images, Video, Text, Credit: SpaceX.