Feeding Galaxy Caught in Distant Searchlight

ESO - European Southern Observatory logo.

4 July 2013

ESO’s Very Large Telescope probes growth of galaxies

Artist’s impression of a galaxy accreting material from its surroundings

Astronomers using ESO’s Very Large Telescope have spotted a distant galaxy hungrily snacking on nearby gas. Gas is seen to fall inwards towards the galaxy, creating a flow that both fuels star formation and drives the galaxy’s rotation. This is the best direct observational evidence so far supporting the theory that galaxies pull in and devour nearby material in order to grow and form stars. The results will appear in the 5 July 2013 issue of the journal Science.

Astronomers have always suspected that galaxies grow by pulling in material from their surroundings, but this process has proved very difficult to observe directly. Now ESO’s Very Large Telescope has been used to study a very rare alignment between a distant galaxy [1] and an even more distant quasar — the extremely bright centre of a galaxy powered by a supermassive black hole. The light from the quasar passes through the material around the foreground galaxy before reaching Earth, making it possible to explore in detail the properties of the gas around the galaxy [2]. These new results give the best view so far of a galaxy in the act of feeding.

“This kind of alignment is very rare and it has allowed us to make unique observations,” explains Nicolas Bouché of the Research Institute in Astrophysics and Planetology (IRAP) in Toulouse, France, lead author of the new paper. “We were able to use ESO’s Very Large Telescope to peer at both the galaxy itself and its surrounding gas. This meant we could attack an important problem in galaxy formation: how do galaxies grow and feed star formation?”

Galaxies quickly deplete their reservoirs of gas as they create new stars, and so must somehow be continuously replenished with fresh gas to keep going. Astronomers suspected that the answer to this problem lay in the collection of cool gas from the surroundings by the gravitational pull of the galaxy. In this scenario, a galaxy drags gas inwards, which then circles around the galaxy, rotating with it before falling in. Although some evidence of such accretion had been observed in galaxies before, the motion of the gas and its other properties had not been fully explored up to now.

The sky around the quasar QSO J2246-6015

The astronomers used two instruments known as SINFONI and UVES [3], both of which are mounted on ESO’s VLT at the Paranal Observatory in northern Chile. The new observations showed both how the galaxy itself was rotating, and revealed the composition and motion of the gas outside the galaxy.

“The properties of this vast volume of surrounding gas were exactly what we would expect to find if the cold gas was being pulled in by the galaxy,” says co-author Michael Murphy (Swinburne University of Technology, Melbourne, Australia). “The gas is moving as expected, there is about the expected amount and it also has the right composition to fit the models perfectly. It’s like feeding time for lions at the zoo — this particular galaxy has a voracious appetite, and we’ve discovered how it feeds itself to grow so quickly.”

Astronomers have already found evidence of material around galaxies in the early Universe, but this is the first time that they have been able to show clearly that the material is moving inwards rather than outwards, and also to determine the composition of this fresh fuel for future generations of stars. Without the quasar’s light to act as a probe this surrounding gas would be undetectable.

“In this case we were lucky that the quasar happened to be in just the right place for its light to pass through the infalling gas. The next generation of extremely large telescopes will enable studies with multiple sightlines per galaxy and provide a much more complete view,” concludes co-author Crystal Martin (University of California Santa Barbara, USA).

Notes:

[1] This galaxy was detected in the 2012 redshift z ~ 2 SINFONI survey called the SINFONI Mg II Program for Line Emitters (SIMPLE). The quasar in the background is called QSO J2246-6015, or HE 2243-60 and the galaxy itself lies at a redshift of 2.3285 — meaning that we are seeing it when the Universe was just about two billion years old.

[2] When the quasar light passes through the gas clouds some wavelengths are absorbed. The patterns of these absorption fingerprints can tell astronomers much about the motions and chemical composition of the gas. Without the quasar in the background far less information would have been be obtained — the gas clouds do not shine and are not visible in direct images.

[3] SINFONI is the Spectrograph for INtegral Field Observations in the Near Infrared, while UVES is the Ultraviolet and Visual Echelle Spectrograph. Both are mounted on ESO’s Very Large Telescope. SINFONI revealed the motions of the gas in the galaxy itself and UVES the effects of the gas around the galaxy on the light coming from the more distant quasar.

More information:

This research was presented in a paper entitled “Signatures of Cool Gas Fueling a Star-Forming Galaxy at Redshift 2.3”, to appear in the 5 July 2013 issue of the journal Science.

The team is composed of N. Bouché (CNRS; IRAP, France), M. T. Murphy (Swinburne University of Technology, Melbourne, Australia), G. G. Kacprzak (Swinburne University of Technology, Australia; Australian Research Council Super Science Fellow), C. Péroux (Aix Marseille University, CNRS, France), T. Contini (CNRS; University Paul Sabatier of Toulouse, France), C. L. Martin (University of California Santa Barbara, USA), M. Dessauges-Zavadsky (Observatory of Geneva, Switzerland).

ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning the 39-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

Links:

Photos of the VLT: http://www.eso.org/public/images/archive/search/?adv=&subject_name=Very%20Large%20Telescope

Images, Text, Credits: ESO / L. Calçada / ESA / AOES Medialab / Digitized Sky Survey 2. Acknowledgement: Davide De Martin.

Greetings, Orbiter.ch

At the foot of the Red Planet’s giant volcano

ESA - Mars Express Mission patch.

4 July 2013

 Olympus Mons southeast flank

Hundreds of individual lava flows are seen frozen in time on the flanks of Olympus Mons, the largest volcano in the Solar System.

The images, taken on 21 January 2013 by ESA’s Mars Express, focus on the southeast segment of the giant volcano, which towers some 22 km above the surrounding plains. This is more than double the height of Mauna Kea, the tallest volcano on Earth at 10 km, when measured from its oceanic base to summit.

Olympus Mons in context

Like Mauna Kea, Olympus Mons is a shield volcano, with gently sloping sides that extend outwards at low angles. But unlike other shield volcanoes, it has an abrupt cliff edge, or scarp, separating it from the surrounding plains.

The scarp circles the entire volcano, in places reaching 9 km high. It was likely formed during a number of catastrophic landslides on the flanks of the volcano, during which the resulting debris was transported several hundred kilometres beyond the extent of these images.

Lava flows cover the base of the volcano, punctuated by a handful of pointy and flat-topped blocks that were either rotated or uplifted during the collapse.

Olympus Mons flank topography

The transition from the towering heights of the volcano down onto the flat lava plain at the base of the scarp can be easily seen in the colour-coded topography image.

In the leading colour image and perspective views, extensive networks of narrow, overlapping lava flows are proof of an extremely active volcanic past. The lava, long since solidified, once spilled down the natural contours of the volcano, spreading out into broad fans as it reached the scarp and plains below.

Flows that ended before reaching the scarp did so with rounded tongues, as the lava cooled and crept to a stop.

Perspective view of Olympus Mons flanks

Some lava flows are bounded by steep channel walls, while others were contained in lava tubes. Zooming in to the top left portion of the flank in the leading image reveals one example of an ancient lava tube, its winding track partially exposed in channel segments where the roof of the tunnel has since collapsed.

Perspective view of Olympus Mons flanks

The chaotic lava flows on the flanks provide a stark contrast to the smooth plains seen surrounding the volcano.

Here, only two prominent features are visible: a ‘wrinkle ridge’ in the lower centre of the main image, which formed as lava cooled and contracted to buckle up and distort the surface, and a channel system that branches out into a horseshoe shape. This channel was likely carved by lava, but water may have once flowed here, too.

The flank of Olympus Mons in 3D

The occurrence of only a few small impact craters in this scene shows that it is relatively young compared with more heavily cratered regions elsewhere on Mars – the older the surface, the greater the exposure time to impact events by asteroids or comets.

Furthermore, by looking at how the lava flows overlap, one can determine their relative ages: those that lie on top, cutting through and overprinting other flows, are the youngest.

For example, the vast lava plain surrounding the volcano truncates the majority of lava flows extending from the flanks, suggesting it is younger still, and that it originated from a location outside of this scene.

The volcanic region hosting Olympus Mons and several other large volcanoes is thought to have been active until tens of millions of years ago, relatively recent on the planet’s geological timescale that spans 4.6 billion years.

Related links:

Mars Express overview: http://www.esa.int/Our_Activities/Space_Science/Mars_Express_overview

Mars Express 10 year brochure: http://esamultimedia.esa.int/multimedia/publications/BR-312/

High Resolution Stereo Camera: http://berlinadmin.dlr.de/Missions/express/indexeng.shtml

Behind the lens: http://www.esa.int/Our_Activities/Space_Science/Mars_Express/Behind_the_lens

Frequently asked questions: http://www.esa.int/Our_Activities/Space_Science/Mars_Express/Frequently_asked_questions

ESA Planetary Science archive (PSA): http://www.rssd.esa.int/PSA

NASA Planetary Data System: http://pds-geosciences.wustl.edu/missions/mars_express/hrsc.htm

HRSC data viewer: http://hrscview.fu-berlin.de/

Images, Text, Credits: ESA / DLR / FU Berlin (G. Neukum) / NASA MGS MOLA Science Team.

Best regards, Orbiter.ch

Spacecraft Resource-P issued the first test shots

ROSCOSMOS patch.

03.07.2013

 Artist's view of Resource-P satellite in orbit

July 2, 2013 conducted the first test include electro-optical target surveillance equipment (Geoton) installed on the spacecraft (SC) Resource-P, have been surveyed, and the first images of the Earth. According to preliminary estimates of experts, is currently performing the processing and analysis of the information received, the resulting images are broadly consistent with the specified requirements and confirm the high performance characteristics of the spacecraft.

Launching of the remote sensing of the Earth Resource-P was successfully implemented June 25, 2013 from the Baikonur Cosmodrome launch vehicle Soyuz-2.1b. Since then, the check is made on-board systems of the spacecraft. Parameters for the spacecraft (temperature, pressure in the compartments, the supply voltage) are in the normal range. Comments on the work of the on-board equipment is not.

Flight testing of the spacecraft Resource-P progress:

 One of the first images obtained from satellite Resource-P. 02.07.2013

 Another of the first images obtained from satellite Resource-P. 02.07.2013

Spacecraft Resource-P created SRP TsSKB Progress on the basis of the existing backlog and project developments to improve its performance targets in the following key areas: increasing the number of narrow spectral ranges from 3 to 5, providing hyperspectral and stereo, snap pictures with the provision of accuracy of 10-15 meters, an increase of lifetime spacecraft with 3 to 5 years.

Space complex Resource-P is for high-precision, detailed broadband and hyperspectral optical-electronic monitoring Earth's surface. This spacecraft was the second in a series of satellites of the "resource" in the domestic constellation of civilian remote sensing of the Earth c detailed level permissions.

Resource-P (Resurs-P) is intended to inform the following applications of Earth observation:

- Compiling and updating the general geographic, thematic and topographic maps;

- Control of pollution and environmental degradation;

- Inventory of natural resources and monitor business processes to ensure the rational activity in various sectors of the economy;

- Information management activities for oil exploration, natural gas, ore and other mineral deposits;

- Control of development of territories, to obtain data for engineering evaluation areas for the benefit of economic activity;

- Control of water conservation and protected areas;

- Assess ice conditions;

- Observation of emergencies, disasters, accidents, man-made disasters, as well as assess their implications for planning remediation.

The information obtained can also be used to promote international cooperation in the Russian part of the global Earth observations and solutions of other pressing problems of remote sensing of the Earth.

Other of the first images obtained from satellite Resource-P. 02.07.2013

Resource-P - a device with a qualitatively new features, including the use on it a special target equipment. One of the basic principles of formation of shape space complex (CC) Resource-P is the use of technical solutions which have been accumulated in creating QC Resource-DK. Were retained capabilities of the spacecraft Resource-DK in width of the capture and the level of resolution in panchromatic and spectral ranges. It operates at near-circular sun-synchronous orbit, which can significantly improve the observations on the Resurs-DK, working on an elliptical orbit. The new spacecraft will be able to shoot at the same height and in the same lighting conditions. The frequency of observation is reduced from six to three days. Furthermore, improved consumer properties and precision reference images transmitted to Earth dynamic characteristics of the spacecraft.

Capacity of tactical and technical characteristics of the new spacecraft achieved through the use of several types of imaging equipment. At the Resource-P is set opto-electronic equipment, which will deliver highly detailed images with a resolution of 1 m with a height of 475 km in the panchromatic band, a narrow spectral bands with a resolution of at least 4.3 meters.

 Resource-P description (in Russian)

The task of equipment Resource-P introduced two other types of imaging equipment: hyperspectral survey equipment - GSA (development of CMH) and a set of wide field multispectral imaging equipment - KSHMSA (development branch SRP TsSKB Progress - SPE OPTEKS ). Locking band hyperspectral instrument is 25 km and a resolution of about 25 m KSHMSA allows detailed observation with wide with a resolution of 12 m swath of 100 km, with a resolution of 60 m - a swath width of 440 km. Together with panchromatic images allows simultaneous recording at fixed spectral ranges.

The presence of this equipment will increase list and quality of the spacecraft solved problems in the socio-economic development of the country and its regions.

ROSCOSMOS Press Release: http://www.federalspace.ru/main.php?id=2&nid=20195

Images, Text, Credits: Press Service of the Russian Federal Space Agency (Roscosmos PAO) / ROSCOSMOS / Translation: Orbiter.ch Aerospace.

Greetings, Orbiter.ch

Anniversary of the Mars Pathfinder Landing

NASA - Mars Pathfinder Mission patch.

July 3, 2013

Mars Pathfinder was launched on Dec. 4, 1996 at 1:58:07 am EST on a Delta II rocket. After an uneventful journey, the spacecraft safely landed on the surface of Mars on July 4, 1997. The first set of data was received shortly after 5:00 p.m. followed by the release of images at 9:30 p.m. The Sojourner rover, with three Lewis components, then began its Martian trek and returned images and other data over the course of three months. After operating on the surface of Mars three times longer than expected and returning a tremendous amount of new information about the red planet, NASA's Mars Pathfinder mission completed the last successful data transmission cycle from Pathfinder at 6:23 a.m. EDT on Sept. 27, 1997.

A panoramic view of Pathfinder's Ares Vallis landing site reveals traces of a warmer, wetter past, showing a floodplain covered with a variety of rock types, boulders, rounded and semi-rounded cobbles and pebbles. These rocks and pebbles are thought to have been swept down and deposited by floods which occurred early in Mars' evolution in the Ares and Tiu regions near the Pathfinder landing site.

The image, which is a 75-frame, color-enhanced mosaic taken by the Imager for Mars Pathfinder, looks to the southwest toward the Rock Garden, a cluster of large, angular rocks tilted in a downstream direction from the floods. The Pathfinder rover, Sojourner, is shown snuggled against a rock nicknamed Moe. The south peak of two hills, known as Twin Peaks, can be seen on the horizon, about 1 kilometer (6/10ths of a mile) from the lander. The rocky surface is comprised of materials washed down from the highlands and deposited in this ancient outflow channel by a catastrophic flood.

Image above: Artist's view of the Mars Pathfinder arrived at the red planet on July 4, 1997.Image credit: NASA / JPL.

The remarkably successful Mars Pathfinder spacecraft, part of NASA's Discovery program of fast track, low-cost missions with highly focused science objectives, was the first spacecraft to explore Mars in more than 20 years. In all, during its three months of operations, the mission returned about 2.6 gigabits of data, which included more than 16,000 images of the Martian landscape from the lander camera, 550 images from the rover and about 8.5 million temperature, pressure and wind measurements.

For more information about Mars Pathfinder Mission, visit: http://www.nasa.gov/mission_pages/mars-pathfinder/ and http://mars.jpl.nasa.gov/MPF/

Images, Text, Credits: NASA / JPL.

Cheers, Orbiter.ch

Long-Running NASA / CNES Ocean Satellite Takes Final Bow

NASA / CNES - Jason-1 Ocean satellite patch.

July 3, 2013

Image above: Artist's concept of the joint NASA/CNES Jason-1 ocean altimetry satellite. During its 11-1/2-year life, Jason-1 helped create a 20-plus-year climate record of global ocean surface topography, providing new insights into ocean circulation, tracking our rising seas and enabling more accurate weather, ocean and climate forecasts. Image Credit: NASA/JPL-Caltech.

The curtain has come down on a superstar of the satellite oceanography world that played the "Great Blue Way" of the world's ocean for 11-1/2 years. The successful joint NASA and Centre National d'Etudes Spatiales (CNES) Jason-1 ocean altimetry satellite was decommissioned this week following the loss of its last remaining transmitter.

Launched Dec. 7, 2001, and designed to last three to five years, Jason-1 helped create a revolutionary 20-plus-year climate data record of global ocean surface topography that began in 1992 with the launch of the NASA/CNES Topex/Poseidon satellite. For more than 53,500 orbits of our planet, Jason-1 precisely mapped sea level, wind speed and wave height for more than 95 percent of Earth's ice-free ocean every 10 days. The mission provided new insights into ocean circulation, tracked our rising seas and enabled more accurate weather, ocean and climate forecasts. 

"Jason-1 has been a resounding scientific, technical and international success," said John Grunsfeld, associate administrator of NASA's Science Mission Directorate in Washington. "The mission met all of its requirements, performed an extended mission and demonstrated how a long-term climate data record should be established from successively launched satellites. Since launch, it has charted nearly 1.6 inches (4 centimeters) of rise in global sea levels, a critical measure of climate change and a direct result of global warming. The Jason satellite series provides the most accurate measure of this impact, which is felt all over the globe."

Graphic above: Jason-1 contributed to this 20-year data record of the global mean sea level change, providing the first direct measurement of this important indicator of global climate change.
Image Credit: University of Colorado.

During parts of its mission, Jason-1 flew in carefully coordinated orbits with both its predecessor Topex/Poseidon and its successor, the Ocean Surface Topography Mission/Jason-2, launched in 2008. These coordinated orbit periods, which lasted about three years each, cross-calibrated the satellites, making possible a 20-plus-year unbroken climate record of sea level change. These coordination periods also doubled data coverage.

Combined with data from the European Space Agency's Envisat mission, which also measured sea level from space, these data allow scientists to study smaller-scale ocean circulation phenomena, such as coastal tides, ocean eddies, currents and fronts. These small-scale features are thought to be responsible for transporting and mixing heat and other properties, such as nutrients and dissolved carbon dioxide, within the ocean.

"Jason-1 was an exemplary and multi-faceted altimeter mission and contributed so much to so many scientific disciplines," said Jean-Yves Le Gall, CNES president in Paris. "Not only did Jason-1 extend the precise climate record established by Topex/Poseidon, it made invaluable observations for mesoscale ocean studies on its second, interleaved orbit. Even from its 'graveyard' orbit, Jason-1 continued to make unprecedented new observations of the Earth's gravity field, with precise measurements right till the end."

The in-orbit Jason-2 mission, operated by the meteorological agencies of the United States and Europe (the National Oceanic and Atmospheric Administration and EUMETSAT, respectively) in collaboration with NASA and CNES, is in good health and continues to collect science and operational data. This same U.S./European team is preparing to launch the next satellite in the series, Jason-3, in March 2015. 

Image above: Regional changes in sea level based on the 19-year trend from 1993 through 2012, as measured using radar altimeter data from several satellites, including the NASA/CNES Jason-1 mission. Reds and purples represent the largest increases in sea level, with blues representing the largest decreases. These changes reflect the impact of decadal-scale climate variability on the regional distribution of sea level rise. Image Credit: University of Colorado.

Contact was lost with the Jason-1 satellite on June 21 when it was out of visibility of ground stations. At the time of the last contact, Jason-1 and its instruments were healthy, with no indications of any alarms or anomalies. Subsequent attempts to re-establish spacecraft communications from U.S. and French ground stations were unsuccessful. Extensive engineering operations undertaken to recover downlink communications also were unsuccessful.

After consultation with the spacecraft and transmitter manufacturers, it was determined a non-recoverable failure with the last remaining transmitter on Jason-1 was the cause of the loss of contact. The spacecraft's other transmitter experienced a permanent failure in September 2005. There now is no remaining capability to retrieve data from the Jason-1 spacecraft. 

On July 1, mission controllers commanded Jason-1 into a safe hold state that reinitialized the satellite. After making several more unsuccessful attempts to locate a signal, mission managers at CNES and NASA decided to proceed with decommissioning Jason-1.  The satellite was then commanded to turn off its magnetometer and reaction wheels. Without these attitude control systems, Jason-1 and its solar panels will slowly drift away from pointing at the sun and its batteries will discharge, leaving it totally inert within the next 90 days. The spacecraft will not reenter Earth's atmosphere for at least 1,000 years.

"Like its predecessor Topex/Poseidon, Jason-1 provided one of the most comprehensive pictures of changes in the tropical Pacific Ocean, including the comings and goings of El Nino and La Nina events," said Lee-Lueng Fu, Jason-1 project scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "These Pacific Ocean climate cycles are responsible for major shifts in sea level, ocean temperatures and rainfall every two to five years and can sometimes be so large that worldwide weather patterns are affected. Jason-1 data have been instrumental in monitoring and predicting these ever-changing cycles."

In the spring of 2012, based on concern over the limited redundancy of Jason-1's aging control systems, NASA and CNES moved the satellite into its planned final "graveyard" orbit, depleted its extra fuel and reconfigured the mission to make observations that will improve our knowledge of Earth's gravity field over the ocean, in addition to delivering its oceanographic data products.

The first full 406-day marine gravity mission was completed on June 17. The resulting data have already led to the discovery of numerous small seamounts, which are underwater mountains that rise above the deep-sea floor. The data also have significantly increased the resolution of Earth's gravity field over the ocean, while increasing our knowledge of ocean bathymetry, which is the underwater depth of the ocean floor.

JPL manages the U.S. portion of the Jason-1 mission for NASA's Science Mission Directorate. CNES manages the French portion of the mission.

For more information on Jason-1, visit: http://sealevel.jpl.nasa.gov and http://www.aviso.oceanobs.com .

The California Institute of Technology in Pasadena manages JPL for NASA.

Images (mentioned), Text, Credits: NASA / Steve Cole / JPL / Alan Buis / Centre National d'Etudes Spatiales, Paris, France / Julien Watelet.

Best regards, Orbiter.ch

Mars Rover Opportunity Passes Half-Way Point to Next Destination

NASA - Mars Exploration Rover B "Opportunity" (MER-B) patch.

July 3, 2013

NASA's Mars Exploration Rover Opportunity has driven more than half of the distance needed to get from a site where it spent 22 months to its next destination.

The rover has less than half a mile (800 meters) to go to finish a 1.2-mile (2-kilometer) dash from one crater-rim segment, where it worked since mid-2011, to another, where mission controllers intend to keep Opportunity busy during the upcoming Martian winter.

Opportunity departed the southern tip of the "Cape York" segment six weeks ago and headed south for "Solander Point." Both are raised portions of the western rim of 14-mile-wide (22-kilometer-wide) Endeavour Crater, offering access to older geological deposits than the rover visited during its first seven years on Mars. Opportunity was launched from Florida on July 7, 2003, EDT (July 8, UTC). It landed on Mars Jan. 24, 2004, PDT (Jan. 25, EDT and UTC).

Image above: This view shows the terrain that NASA's Mars Exploration Rover Opportunity is crossing in a flat area called "Botany Bay" on the way toward "Solander Point," which is visible on the horizon. Image Credit: NASA/JPL-Caltech.

A flatter area called Botany Bay separates Cape York from Solander Point.

"We are making very good progress crossing 'Botany Bay,'" said John Callas of NASA's Jet Propulsion Laboratory, Pasadena, Calif., who is project manager for the nearly decade-old mission.

The terrain is favorable for the trek.

"The surface that Opportunity is driving across in Botany Bay is polygonally fractured outcrop that is remarkably good for driving," said Brad Joliff, an Opportunity science team member and long-term planner at Washington University in St. Louis. "The plates of outcrop, like a tiled mosaic pavement, have a thin covering of soil, not enough to form the wind-blown ripples we've had to deal with during some other long treks. The outcrop plates are light-toned, and the cracks between them are filled with dark, basaltic soil and our old friends the 'blueberries.'"

The BB-size spherules nicknamed "blueberries" are hematite-rich, erosion-resistant concretions that Opportunity discovered at its landing site and continued seeing on much of the ground between there and Endeavour Crater.

Mars Exploration Rover B "Opportunity" (MER-B). Image Credit: NASA/JPL-Caltech

The rise of Solander Point to the south gives the team a very visible destination during the drive. That destination offers both a tall cross section of rock layers for examination and also an expanse of terrain that includes a north-facing slope, which is favorable for the solar-powered rover to stay active and mobile through the coming Martian southern-hemisphere winter.

JPL, a division of the California Institute of Technology in Pasadena, manages the Mars Exploration Rover Project for NASA's Science Mission Directorate. For more about Spirit and Opportunity, visit http://www.nasa.gov/rovers and http://marsrovers.jpl.nasa.gov . You can follow the project on Twitter and on Facebook at: http://twitter.com/MarsRovers and http://www.facebook.com/mars.rovers .

Images (mentioned), Text, Credits: NASA / JPL / Guy Webster.

Greetings, Orbiter.ch

Comet ISON Brings Holiday Fireworks

NASA - Hubble Space Telescope patch.

July 2, 2013

This July Fourth the solar system is showing off some fireworks of its own.

Superficially resembling a skyrocket, comet ISON is hurtling toward the sun presently at a whopping 48,000 mph.

Hubble View of Comet ISON

Video above: Hubble View of Comet ISON. Video Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA).

Its swift motion is captured in this time-lapse movie made from a sequence of pictures taken May 8, 2013, by NASA’s Hubble Space Telescope. At the time the images were taken, the comet was 403 million miles from Earth, between the orbits of Mars and Jupiter.

The movie shows a sequence of Hubble observations taken over a 43-minute span and compresses this into just five seconds. The comet travels 34,000 miles in this brief video, or 7 percent of the distance between Earth and the moon. The deep-space visitor streaks silently against the background stars.

Unlike a firework, the comet is not combusting, but in fact is pretty cold. Its skyrocket-looking tail is really a streamer of gas and dust bleeding off the icy nucleus, which is surrounded by a bright star-like-looking coma. The pressure of the solar wind sweeps the material into a tail, like a breeze blowing a windsock.

As the comet warms as it moves closer to the sun, its rate of sublimation (a process similar to evaporation in which solid matter transitions directly into gas) will increase. The comet will get brighter and its tail will grow longer. The comet is predicted to reach naked-eye visibility in November.

The comet is named after the organization that discovered it, the Russia-based International Scientific Optical Network.

Image above: This false-color, visible-light image was taken with Hubble’s Wide Field Camera 3. Image Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA).

The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center in Greenbelt, Md., manages the telescope. The Space Telescope Science Institute in Baltimore, Md., conducts Hubble science operations. STScI is operated by the Association of Universities for Research in Astronomy Inc., in Washington, D.C.

Related Links:
NASA's Asteroids and Comet Watch website: http://www.nasa.gov/mission_pages/asteroids/main/index.html

More on this image from the Space Telescope Science Institute: 1 / 2: http://hubblesite.org/news/2013/24 and http://heritage.stsci.edu/2013/24

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

For more information about NASA / ESA Hubble Space Telescope: http://www.nasa.gov/hubble and http://www.spacetelescope.org/

Image (mentioned), Video (mentioned), Text, Credits: ESA / Space Telescope Science Institute / Ray Villard / Zolt Levay.

Best regards, Orbiter.ch