vendredi 24 avril 2015

Hubble's Look at an Extragalactic Peculiarity

NASA - Hubble Space Telescope patch.

April 24, 2015

This galaxy goes by the name of ESO 162-17 and is located about 40 million light-years away in the constellation of Carina. At first glance this image seems like a fairly standard picture of a galaxy with dark patches of dust and bright patches of young, blue stars. However, a closer look reveals several peculiar features.

Firstly, ESO 162-17 is what is known as a peculiar galaxy — a galaxy that has gone through interactions with its cosmic neighbors, resulting in an unusual amount of dust and gas, an irregular shape, or a strange composition.

Secondly, on February 23, 2010 astronomers observed the supernova known as SN 2010ae nestled within this galaxy. The supernova belongs to a recently discovered class of supernovae called Type Iax supernovae. This class of objects is related to the better known Type-Ia supernovae.

Type Ia supernovae result when a white dwarf accumulates enough mass either from a companion or, rarely, through collision with another white dwarf, to initiate a catastrophic collapse followed by a spectacular explosion as a supernova. Type Iax supernovae also involve a white dwarf as the central star, but in this case it may survive the event. Type Iax supernovae are much fainter and rarer than Type Ia supernovae, and their exact mechanism is still a matter of open debate.

Hubble orbiting Earth

The rather beautiful four-pointed shape of foreground stars distributed around ESO 162-17 also draws the eye. This is an optical effect introduced as the incoming light is diffracted by the four struts that support the Hubble Space Telescope’s small secondary mirror.

Related links:

ESO 162-17:

Hubble Space Telescope’s small secondary mirror:

For more information about Hubble Space Telescope, visit: and

Image, Video, Text, Credits: ESA/Hubble & NASA/Karl Hille.


jeudi 23 avril 2015

Experiment Work Inside and Outside Space Station

ISS - Expedition 43 Mission patch.

April 23, 2015

The Expedition 43 lab assistants conducted biomedical science in the International Space Station on Wednesday April 22. Meanwhile, controllers on the ground will remotely maneuver the Canadarm2 outside the station to experiment with the possibility of servicing satellites on orbit for longer missions.

The crew participated in a wide variety of life science studies. The Myco experiment, which analyzes nose, throat and skin samples, examines how microorganisms on the space station can affect a crew member’s allergies and illnesses. Another study, Interactions, explores how crews from different cultures learn to work with each other. More Rodent Research work took place, as the astronauts readied samples for return to Earth and checked out the rodents’ habitat.

Image above: The International Space Station’s Canadarm2 and Dextre is seen outside the SpaceX Dragon cargo ship. Image Credit: NASA.

Crew members also underwent medical exams, checking vital signs such as temperature and blood pressure. Later there were crew eye checks as doctors on the ground explore how microgravity affects vision.

The Robotics Refueling Mission, a joint study between NASA and the Canadian Space Agency, investigates satellite repair and servicing techniques in space. Operators on the ground use the station’s special purpose dexterous manipulator, better known as Dextre, on the end of the Canadarm2, for fine robotics manipulation. Engineers are looking to determine whether it’s possible to refuel satellites and test electrical connections robotically.

Related links:

Robotics Refueling Mission:

Myco experiment:

Interactions experiment:

Rodent Research:

For more information about the International Space Station (ISS), visit:

Images (mentioned), Text, Credit: NASA.

Rosetta - OSIRIS catches activity in the act

ESA - Rosetta Mission patch.

April 23, 2015

Rosetta’s scientific imaging system OSIRIS has witnessed a new jet of dust emerging from the surface of Comet 67P/Churyumov-Gerasimenko. The image was presented during the European Geosciences Union General Assembly, EGU, in Vienna last week.

Sometimes it is all a matter of being in the right place at the right time. Or, as in the case of ESA’s space probe Rosetta, of opening your eyes at the exactly right moment. In mid-March, the OSIRIS camera was able to catch the elusive moment when a new dust jet from comet 67P/C-G burst into life.

Comet jet awakens

Image above: Rosetta’s OSIRIS wide-angle camera captures the moment a jet bursts into action. The first image was captured at 07:13 CET on 12 March 2015, the second two minutes later. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA.

The comet’s activity has been significantly increasing over the last weeks and months. As the comet moves closer to the Sun along its orbit, its nucleus gets warmer and warmer. Frozen gases sublimate from its surface, carrying dust particles with it and enshrouding the nucleus in a dense coma. With only four months to go until perihelion – the closest point to the Sun – this process is well underway, with pronounced dust jets seen at all times on the comet’s day side.

The two images released today show the remarkable onset of such a jet for the first time. They were taken on 12 March from a distance of 75 kilometres. In the first image, obtained at 07:13 CET, several rays of dust jets frame the upper, illuminated side of the comet. The dark underside shows no such features. Two minutes later, the picture has changed: a spectacular new jet has emerged on the dark side, hurtling dust into space and displaying a clearly discernable fine structure.

Image above: The scene at 07:13 CET on 12 March. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA.

“This was a chance discovery,” says OSIRIS principal investigator Holger Sierks from the Max Planck Institute for Solar System Research (MPS) in Germany. “No one has ever witnessed the wake-up of a dust jet before. It is impossible to plan such an image.”

Tracking variations in brightness along the jet, the researchers estimated the velocity of the dust grains to be at least eight metres per second. This is compatible with measurements made with Rosetta’s GIADA instrument on other occasions, for dust particles emitted from the comet’s surface.

Surprisingly, the new-born jet arises from a shadowed area on the underside of the comet, close to the centre of the Imhotep region. So far cometary activity has only been observed on the comet’s day-side.

“In these images we see Imhotep on the brink of dawn,” OSIRIS scientist Jean-Baptiste Vincent from the MPS explains. “It is possible that the first rays of sunlight hit some cliffs or outcrops that remained hidden to Rosetta due to the orbital position at the time.”

The onset of activity could also be the result of a different type of more explosive activity. That is, the outburst could have been triggered by a wave of heat reaching ices trapped in a deeper layer beneath the surface.

Image above: The scene at 07:15 CET on 12 March. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA.

OSIRIS could not continue to observe the new feature after 07:17 CET because Imhotep was soon fully illuminated, making it impossible to discern individual jets in the overexposed coma. It is therefore not clear whether Rosetta witnessed the birth of a continuous jet or a short-lived outburst.

“Usually, 67P’s dust-jets are rather long-lived,” says Vincent, who has been monitoring the comet’s activity over the past months. “Most of them last for a full dayside rotation of approximately six hours and even reappear in the next rotation.”

However, scientists believe that eruptive outbursts can also occur. This style of outburst might have triggered the observed increase in brightness in the comet’s coma on 30 April 2014. At that time the coma expanded over 1800 kilometres – but faded again a few weeks later.

Last month’s unique observation, along with the continued monitoring of 67P/C-G’s global activity patterns, will give the scientists the chance to test different models of activity.

About OSIRIS: The scientific imaging system OSIRIS was built by a consortium led by the Max Planck Institute for Solar System Research (Germany) in collaboration with CISAS, University of Padova (Italy), the Laboratoire d'Astrophysique de Marseille (France), the Instituto de Astrofísica de Andalucia, CSIC (Spain), the Scientific Support Office of the European Space Agency (The Netherlands), the Instituto Nacional de Técnica Aeroespacial (Spain), the Universidad Politéchnica de Madrid (Spain), the Department of Physics and Astronomy of Uppsala University (Sweden), and the Institute of Computer and Network Engineering of the TU Braunschweig (Germany). OSIRIS was financially supported by the national funding agencies of Germany (DLR), France (CNES), Italy (ASI), Spain (MEC), and Sweden (SNSB) and the ESA Technical Directorate.

Related link:

European Geosciences Union General Assembly (EGU):

For more information about Rosetta mission, visit:

For more information about OSIRIS, visit:

More about...

Rosetta overview:

Rosetta factsheet:

Frequently asked questions:

In depth:

Rosetta in depth:

Images (mentioned), Text, Credit: European Space Agency (ESA).

Celestial fireworks celebrate Hubble’s 25th anniversary

ESA - Hubble Space Telescope patch.

23 April 2015

Westerlund 2 — Hubble’s 25th anniversary image

The glittering tapestry of young stars flaring to life in this new NASA/ESA Hubble Space Telescope image aptly resembles an exploding shell in a fireworks display. This vibrant image of the star cluster Westerlund 2 has been released to celebrate Hubble’s 25th year in orbit and a quarter of a century of new discoveries, stunning images and outstanding science.

Wide-field image of Westerlund 2 (ground-based image)

On 24 April 1990 the NASA/ESA Hubble Space Telescope was sent into orbit aboard the space shuttle Discovery as the first space telescope of its kind. It offered a new view of the Universe and has, for 25 years, reached and surpassed all expectations, beaming back data and images that have changed scientists’ understanding of the Universe and the public’s perception of it.

The star cluster Westerlund 2

In this image, the sparkling centrepiece of Hubble’s silver anniversary fireworks is a giant cluster of about 3000 stars called Westerlund 2 [1][2]. The cluster resides in a raucous stellar breeding ground known as Gum 29, located 20 000 light-years away in the constellation Carina.

Star-forming region Gum 29

The stellar nursery is difficult to observe because it is surrounded by dust, but Hubble’s Wide Field Camera 3 peered through the dusty veil in near-infrared light, giving astronomers a clear view of the cluster. Hubble’s sharp vision resolves the dense concentration of stars in the central cluster, which measures only about 10 light-years across.

Pillars around Westerlund 2

The giant star cluster is only about two million years old, but contains some of the brightest, hottest and most massive stars ever discovered. Some of the heftiest stars are carving deep cavities in the surrounding material by unleashing torrents of ultraviolet light and high speed streams of charged particles, known as stellar winds. These are etching away the enveloping hydrogen gas cloud in which the stars were born and are responsible for the weird and wonderful shapes of the clouds of gas and dust in the image.

New stars around Westerlund 2

The pillars in the image are composed of dense gas and dust, and are resisting erosion from the fierce radiation and powerful winds. These gaseous monoliths are a few light-years tall and point to the central cluster. Other dense regions surround the pillars, including dark filaments of dust and gas.

Zoom into Westerlund 2

Besides sculpting the gaseous terrain, the brilliant stars can also help create a succeeding generation of offspring. When the stellar winds hit dense walls of gas, they create shocks, which generate a new wave of star birth along the wall of the cavity. The red dots scattered throughout the landscape are a rich population of forming stars that are still wrapped in their gas and dust cocoons. These stellar foetuses have not yet ignited the hydrogen in their cores to light-up as stars. However, Hubble’s near-infrared vision allows astronomers to identify these fledglings. The brilliant blue stars seen throughout the image are mostly in the foreground.

Westerlund 2 for fulldome

The image’s central region, containing the star cluster, blends visible-light data taken by the Advanced Camera for Surveys and near-infrared exposures taken by the Wide Field Camera 3. The surrounding region is composed of visible-light observations taken by the Advanced Camera for Surveys.

Pan across Westerlund 2

This image is a testament to Hubble’s observational power and demonstrates that, even with 25 years of operations under its belt, Hubble’s story is by no means over. Hubble has set the stage for its companion the James Webb Space Telescope — scheduled for launch in 2018 — but will not be immediately replaced by this new feat of engineering, instead working alongside it. Now, 25 years after launch, is the time to celebrate Hubble’s future potential as well as its remarkable history.

Flight through star cluster Westerlund 2 — fast

Flight through star cluster Westerlund 2 - slow


[1] A new anniversary image is released every year; last year Hubble snapped the ethereal Monkey Head Nebula (heic1406). The year 2013 saw the release of a strikingly delicate view of the Horsehead Nebula (heic1307), and Hubble’s 22nd year was marked by a huge mosaic of a celestial spider (heic1206)! Other images include a multicoloured view of Saturn (opo9818a), a Tolkien-esque shot of the Carina Nebula (heic1007a), and a beautiful cosmic rose made up of merging galaxies (heic1107a). More anniversary images can be seen here.

[2] Westerlund 2 is named after Swedish astronomer Bengt Westerlund, who discovered the grouping in the 1960s.

Notes for editors:

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

The original observations of Westerlund 2 were obtained by the science team: Antonella Nota (ESA/STScI), Elena Sabbi (STScI), Eva Grebel and Peter Zeidler (Astronomisches Rechen-Institut Heidelberg), Monica Tosi (INAF, Osservatorio Astronomico di Bologna), Alceste Bonanos (National Observatory of Athens, Astronomical Institute), Carol Christian (STScI/AURA) and Selma de Mink (University of Amsterdam). Follow-up observations were made by the Hubble Heritage team: Zoltan Levay (STScI), Max Mutchler, Jennifer Mack, Lisa Frattare, Shelly Meyett, Mario Livio, Carol Christian (STScI/AURA), and Keith Noll (NASA/GSFC).


Hubblecast Episode 84: A starry snapshot for Hubble’s 25th:

Images of Hubble:

For more information on the anniversary activities you can visit the website:

Images, Text, Credit: NASA, ESA, the Hubble Heritage Team (STScI/AURA), A. Nota (ESA/STScI), and the Westerlund 2 Science Team/Digitized Sky Survey 2/Videos: NASA, ESA, Digitized Sky Survey 2, the Hubble Heritage Team (STScI/AURA), A. Nota (ESA/STScI), and the Westerlund 2 Science Team/N. Risinger ( Johan Back Monell (

Best regards,

Jason-3 Will Add to Record of the Sea's Rise and Fall

NASA / NOAA - Jason 3 Mission logo.

April 23, 2015

Artist's rendering of Jason-3. Image Credits: NASA/JPL-Caltech

You can't predict the outcome of a marathon from the runners' times in the first few miles. You’ve got to see the whole race. Global climate change is like that: You can't understand it if all you have is a few years of data from a few locations. That's one reason that a fourth-generation satellite launching this summer is something to get excited about.

Jason-3, a mission led by the National Oceanic and Atmospheric Administration that is currently scheduled to launch on July 22, is the latest in a series of U.S.-European satellite missions that have been measuring the height of the ocean surface for 23 years. Sea level height is a critical piece of evidence about Earth's natural cycles and how humans are affecting our planet. Knowing sea level height also improves hurricane forecasts, navigation and the efficiency of fisheries and other offshore industries (see below).

Most people think that, except for waves, the ocean is flat. It's not. The ocean has topography just as land does. Ocean currents cause hills and valleys in the sea surface that vary in height by more than six feet (two meters) from one place to another. And just as Earth's rocky landscapes change because of erosion and many other causes, its watery hills and valleys also change. High points on the sea surface tend to be over warm water and valleys over cold water, with currents flowing around the hills and valleys. Because the ocean absorbs more than 90 percent of the heat trapped by human-emitted greenhouse gases, monitoring the changing ocean topography is a key to understanding how the ocean responds to and influences climate change.

Jason-3. Video Credits: NASA/JPL-Caltech

Of course, the ocean changes naturally as well, with cycles like the Pacific Ocean's El Niño and Pacific Decadal Oscillation (PDO), which change the height and temperature of the sea surface. Scientists want to understand these natural cycles better. "Jason-3 might witness a new phase of the PDO," said Josh Willis of NASA's Jet Propulsion Laboratory, NASA's Jason-3 project scientist. The current cold phase produces colder-than-normal sea surface temperatures in the East Pacific; some oceanographers have theorized that the reason global atmospheric temperatures have not increased significantly since about 2000 is that the PDO switched to its cold phase at that time, and the cooler ocean surface has moderated air temperatures ever since.

Jason-3's predecessors were Topex/Poseidon (launched in 1992), Jason-1 (2001) and Jason-2 (2008, still active). The primary science instrument in all the satellites is a radar altimeter, which sends a microwave pulse to the ocean's surface and times how long the signals take to return. Combined with information on the precise location of the spacecraft, the returned radar signals give a record of sea-surface height. The instrument has not had a major redesign since Jason-1. "We did it right the first time," Willis joked.

Jason-3 Anticipated Launch: 2015. Image Credits: NASA/JPL-Caltech

When Topex/Poseidon launched, researchers did not expect its accuracy to be good enough to observe global sea level rise, but the altimetry measurement system outperformed expectations from the start, proving to be accurate within about an inch (a few centimeters) for a single measurement. The series has observed about 2.4 inches (6 centimeters) of global sea level rise in 23 years. In that time, "We're already seeing increased coastal erosion, more frequent flooding -- the 100-year flood in San Francisco is now the 10-year flood," Willis noted.

"Every decade, the planet's climate evolves and our influence on it grows. So every decade we're actually measuring a new world," said Willis. "That's why we need to continue these observations."

TOPEX/Poseidon Measurement System. Image Credit: NASA

Jason-3 is an international partnership led by the National Oceanic and Atmospheric Administration with participation from NASA, France's Centre Nationale d'Etudes Spatiales (the French space agency) and EUMETSAT, the European Organisation for the Exploitation of Meteorological Satellites. JPL built Jason-3's radiometer, GPS and laser reflector and is procuring the launch and will help oversee the science team, which is responsible for ensuring the quality of the data.

A Few Applications of Spaceborne Altimetry:

1. Civilian sailors and the U.S. Navy use the series' near-real-time data on currents, eddies, winds and waves to aid surface and underwater navigation.

2.  Offshore industries use the data to improve safety and efficiency. Information on eddy currents in the Gulf of Mexico has been used by marine operators to schedule offshore drilling operations, with significant cost savings.

3. Satellite altimeter data are routinely used in forecasting hurricane strength. The data provide information on the potential heat stored in the oceans, which is available to fuel and intensify tropical cyclones.

4.  Since 1997, satellite altimetry data have been used in NOAA’s operational El Niño-Southern Oscillation analysis and forecast system. El Niño occurrences are the dominant force in the Pacific Ocean.

5.  Bangladesh -- a country whose short history has encompassed catastrophic river floods that killed thousands -- now uses Jason-2 river level data in its flood forecasting and warning system. In 2014, the system provided the longest lead time for flood warnings ever produced in the nation.

For more about NASA's ocean surface altimetry missions, visit:

Images (mentioned), Text, Credits: NASA Earth Science News Team/Carol Rasmussen/JPL/Alan Buis.


NASA Soil Moisture Mission Produces First Global Maps

NASA - SMAP Mission patch.

April 23, 2015

Image above: SMAP radar image acquired from data from March 31 to April 3, 2015. Weaker radar signals (blues) reflect low soil moisture or lack of vegetation, such as in deserts. Strong radar signals (reds) are seen in forests. SMAP's radar also takes data over the ocean and sea ice.
Credits: NASA/JPL-Caltech/GSFC.

With its antenna now spinning at full speed, NASA's new Soil Moisture Active Passive (SMAP) observatory has successfully re-tested its science instruments and generated its first global maps, a key step to beginning routine science operations next month.

SMAP launched Jan. 31 on a minimum three-year mission to map global soil moisture and detect whether soils are frozen or thawed. The mission will help scientists understand the links among Earth's water, energy and carbon cycles; help reduce uncertainties in predicting weather and climate; and enhance our ability to monitor and predict natural hazards such as floods and droughts.

In late March, mission controllers at NASA's Jet Propulsion Laboratory in Pasadena, California, successfully spun SMAP's 20-foot-wide (6-meter) antenna up to its full speed of 14.6 revolutions per minute in a two-step process. SMAP's spinning antenna makes cone-shaped scans across Earth’s surface, measuring a 620-mile-wide (1,000-kilometer) swath of the ground as it flies above Earth from pole to pole at an altitude of 426 miles (685 kilometers). The wide swath width and polar orbit allow SMAP to map the entire globe with high-resolution radar data every two to three days.

With its spin-up activities complete, the observatory's radar and radiometer instruments were powered on from March 31 to April 3 in a test designed to verify the pointing accuracy of the antenna and the overall performance of the radar and radiometer instruments. The radar data acquired from the test have been processed to generate data products with a spatial resolution of about 19 miles (30 kilometers). The first full global maps produced during the test are online at: and

SMAP's radar, operating at 1.2 gigahertz, works by transmitting microwave pulses to the ground and receiving and measuring the strength of the signals that bounce back from Earth, called backscatter. Water -- including water in soil -- responds differently than dry soil does to microwaves. Water changes the strength of backscatter and microwaves’ polarization (the orientation of the electrical field of the microwaves). Therefore, backscatter from soil containing more moisture is stronger and is polarized differently than backscatter from drier soil. The extent of this difference allows scientists to distinguish the amount of moisture present in the soil. SMAP’s radar emits pulses with two different polarizations, horizontal and vertical, to make a more complete measurement of this effect.

Like the radar, SMAP’s radiometer detects differences in microwaves caused by water in soil; but it measures Earth’s natural microwave emissions at the frequency of 1.4 gigahertz. Around the globe, the most striking difference in these natural emissions is between water and land surfaces. A desert emits microwaves at about three times the rate a lake does. Because the difference is so large, even a small amount of moisture in soil causes a change that a radiometer can measure accurately.

Image above: SMAP radiometer image from March 31 - April 3, 2015 data maps surface microwave emissions as brightness temperatures in Kelvin, with strong emissions in reds and weaker emissions in blues. Vegetated rainforests and dry deserts show strong emissions; Greenland and Antarctica have weak emissions. Image Credits: NASA/JPL-Caltech/GSFC.

In the composite radar image (, global land, ocean and ice conditions are readily apparent. The weaker radar signals measured over the Sahara and Gobi Deserts, depicted in blue shades, reflect their very low soil moisture content and lack of vegetation cover. In contrast, the densely vegetated Amazon and Congo rain forests have very strong radar signals, depicted in reds. In North America, the boreal forests and tree canopies in the Rockies, Sierra Nevada and Cascade mountain ranges, and areas east of the Mississippi River, also have strong radar echoes. Grasslands and prairies in the U.S. Great Plains, a great expanse of flat land, exhibit relatively lower-strength radar echoes.

SMAP's radar also takes data over Earth's ocean and sea ice. Variations in radar data over the open ocean reflect variations in surface wind conditions, with relatively low winds in the tropics and high winds at high latitudes. Arctic sea ice, which contains air bubbles and pockets of brine, produces radar echo strengths similar to those seen over grassland or tundra.

The radiometer data from the instrument test, shown in, have also been processed to map microwave emissions from Earth's surface, expressed as brightness temperatures in Kelvin and at a horizontal spatial resolution of about 25 miles (40 kilometers). Brightness temperature is a measurement of how much microwave radiant energy is traveling up from Earth's surface to the satellite. The Amazon and Congo rainforests produced strong emissions, depicted in red shades, due to their large volumes of biomass. Brightness temperatures in the Sahara Desert reach about 80 degrees Fahrenheit (about 300 Kelvin) due to its low moisture content. The impact of soil moisture is evident over a large region south of the Great Lakes, where an increase in soil moisture due to precipitation in March resulted in relatively cool brightness temperatures of about minus 100 Fahrenheit (about 200 Kelvin). Similar impacts of rain on soil moistures and brightness temperatures are seen in Namibia and Botswana, Africa, where there was significant rainfall in late March.

Soil Moisture Active Passive (SMAP) satellite. Image Credit: NASA

The radiometer brightness temperatures of Earth's ocean are mostly below minus 172 Fahrenheit (160 Kelvin), reflected by its blue shades. However, with the application of a different color scale to highlight the subtle variations over the ocean, the effects of winds on the ocean are also apparent. The brightness temperatures of Greenland and Antarctica are low (approximately 200 Kelvin) due to their low physical temperatures and high emissivity (the efficiency of these polar regions at emitting thermal energy). The brightness temperatures of sea ice fall in the middle range because its salt content is less than the salty water in the ocean, but high enough to distinguish it from land surfaces.

The SMAP mission is required to produce high-resolution maps of global soil moisture and detect whether soils are frozen or thawed. SMAP's radar has two data acquisition functions: one for synthetic aperture radar (SAR) processing to produce radar measurements at a spatial resolution of 0.6 to 1.9 miles (1 to 3 kilometers), and another for low-resolution processing to produce radar measurements at a spatial resolution of 19 miles (30 kilometers). The SAR function will be used over land surfaces and coastal oceans during routine science operations, while low-resolution processing will be exercised over land as well as over global ocean areas. Since the SAR function was only turned on for limited durations during the test from March 31 to April 3, mission scientists did not obtain enough SAR data to produce global high-resolution maps. SMAP has now begun conducting regular SAR observations that will enable high-resolution global mapping of land surfaces about every two to three days.

Scientists will combine measurements from SMAP's radar and radiometer sensors to capitalize on the strengths of each and work around their weaknesses. The radar alone can produce a soil moisture measurement with a spatial resolution of about 1.9 miles (3 kilometers), but the measurement itself is less accurate than the one made by the radiometer. The radiometer alone achieves a highly accurate observation of soil moisture but with a much poorer spatial resolution of about 25 miles (40 kilometers). By combining these separate measurements through advanced data processing, SMAP will provide the user community with a combined soil moisture measurement that has high accuracy and a resolution of 5.6 miles (9 kilometers). The advanced processing required to combine these active and passive measurements is now being functionally checked out, and is the last step in SMAP's postlaunch checkout process. SMAP will offer the individual radar and radiometer data, among other data products.

For more information on SMAP, visit:

For more information about NASA's Earth science activities, visit:

Images )mentioned), Text, Credits: NASA/Tony Greicius.


mercredi 22 avril 2015

Mars Orbiter Views Curiosity Rover in 'Artist's Drive'

NASA - Mars Reconnaissance Orbiter (MRO) patch.

April 22, 2015

Image above: Mars image from the orbiter's High Resolution Imaging Science Experiment (HiRISE) camera. Image Credits: NASA/JPL-Caltech/Univ. of Arizona.

A view from NASA's Mars Reconnaissance Orbiter on April 8, 2015, catches sight of NASA's Curiosity Mars rover passing through a valley called "Artist's Drive" on the lower slope of Mount Sharp.

The image from the orbiter's High Resolution Imaging Science Experiment (HiRISE) camera shows the rover's position after a drive of about 75 feet (23 meters) during the 949th Martian day, or sol, of the rover's work on Mars.

The location of the rover, with its shadow extending toward the right, is indicated with an inscribed rectangle. North is toward the top. The view covers an area about 550 yards (500 meters) across. 

Image above: Unannotated version of Mars image from the orbiter's High Resolution Imaging Science Experiment (HiRISE) camera. Image Credits: NASA/JPL-Caltech/Univ. of Arizona.

Curiosity used a route through Artist's Drive on its way toward higher layers on Mount Sharp after examining exposures of the mountain's basal geological unit at "Pahrump Hills."  The rover's "Logan Pass" science destination is at the bottom left of this image. A wider map of the area is at:

This image is an excerpt from HiRISE observation ESP_040770_1755. Other image products from this observation are available at:

Mars Reconnaissance Orbiter. Image Credits: NASA/JPL-Caltech

The University of Arizona, Tucson, operates HiRISE, which was built by Ball Aerospace & Technologies Corp., Boulder, Colorado. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter Project and Mars Science Laboratory Project for NASA's Science Mission Directorate, Washington.

For more information about Mars Reconnaissance Orbiter (MRO), visit:

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


An experimental rocket crashes after takeoff


April 22, 2015

The accident caused no casualties or damage. There was 900 km north of Moscow.

The accident occurred Wednesday in an uninhabited area of ​​northern Russia, told AFP from a senior local authorities. A Russian experimental rocket crashed shortly after takeoff.

According to this source, who requested anonymity, the military confirmed the incident, saying he had no injuries or damage. The rocket crashed in the region of Arkhanguelsk, about 900 km north of Moscow.

Experimental rocket launch at Plessetsk Cosmodrome

The regional government confirmed the incident to the TASS news agency, explaining that the craft had crashed 7 km from the Plessetsk Cosmodrome, around 09:00 am GMT. According to TASS, quoting military sources, this experimental rocket 9.6 tons, solid propulsion, has veered off course shortly after takeoff. Its launch was conducted by a company of the Russian military-industrial complex, assured the source.

"No danger to the public"

"The accident poses no threat to the people or the environment. The rocket did not contain hazardous substances or materials, "said a National Centre spokesman crisis management at the Interfax news agency.

No details of the rocket has been given by the Russian authorities and officials of the Plessetsk Cosmodrome did not wish to confirm the accident told AFP.

The Russian space industry has been shaken in recent years by a series of stinging setbacks, including the failure of the development of communications satellites orbit or the loss of a probe launched to a satellite of Mars (Phobos).

Overhaul of the Russian space industry

In the summer of 2013, a Proton rocket carrying three Glonass satellites, the future Russian satellite navigation system, and had exploded on takeoff.

However, Russia is successfully launched in late December a new generation of rocket, Angara, commissioning since the end of the Soviet Union and will replace the Proton rocket.

Faced with the difficulties encountered, Moscow launched late January a redesign of its strategic space sector, with the merger of its various structures under the leadership of the Roscosmos space agency and the appointment of a new boss, Igor Komarov.

Image, Text, Credits: AFP/ Aerospace.


ICARUS neutrino experiment to move to Fermilab

CERN - European Organization for Nuclear Research logo.

April 22, 2015

A group of scientists led by Nobel laureate Carlo Rubbia will transport the world’s largest liquid-argon neutrino detector across the Atlantic Ocean from CERN to its new home at the US Department of Energy’s Fermi National Accelerator Laboratory.

The 760-ton, 20-metre-long detector took data for the ICARUS experiment at the Italian Institute for Nuclear Physics (INFN) Gran Sasso National Laboratory in Italy from 2010 to 2014, using a beam of neutrinos sent through the earth from CERN. The detector is now being refurbished at CERN, where it is the first beneficiary of a new test facility for neutrino detectors.

When it arrives at Fermilab, the detector will become part of an on-site suite of three experiments dedicated to studying neutrinos, ghostly particles that are all around us but have given up few of their secrets.

Image above: The ICARUS detector at INFN, Gran Sasso, Italy, before its move to CERN (Image: INFN).

All three detectors will be filled with liquid argon that enables the use of state-of-the-art time projection technology, drawing charged particles created in neutrino interactions toward planes of fine wires that can capture a 3-D image of the tracks those particles leave. Each detector will contribute different yet complementary results to the hunt for a fourth type of neutrino.

“The liquid-argon time projection chamber is a new and very promising technology that we originally developed in the ICARUS collaboration from an initial table-top experiment all the way to a large neutrino detector,” Rubbia said. “It is expected that it will become the leading technology for large liquid-argon detectors, with its ability to record ionizing tracks with millimetre precision.”

Fermilab operates two powerful neutrino beams and is in the process of developing a third, making it the perfect place for the ICARUS detector to continue its scientific exploration. Scientists plan to transport the detector to the United States in 2017.

A planned sequence of three liquid-argon detectors will provide new insights into the three known types of neutrinos and seek a yet unseen fourth type, following hints from other experiments over the past two decades.

Many theories in particle physics predict the existence of a so-called “sterile” neutrino, which would behave differently from the three known types and, if it exists, could provide a route to understanding the mysterious dark matter that makes up 25 percent of the universe. Discovering this fourth type of neutrino would revolutionize physics, changing scientists’ entire picture of the universe and how it works.

“The arrival of ICARUS and the construction of this on-site research programme is a lofty goal in itself,” said Fermilab Director Nigel Lockyer. “But it is also the first step forward in Fermilab’s plan to host a truly international neutrino facility, with the help of our partners from around the world. The future of neutrino research in the United States is bright.”


CERN, the European Organization for Nuclear Research, is one of the world’s largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Universe is made of and how it works. At CERN, the world’s largest and most complex scientific instruments are used to study the basic constituents of matter — the fundamental particles. By studying what happens when these particles collide, physicists learn about the laws of Nature.

The instruments used at CERN are particle accelerators and detectors. Accelerators boost beams of particles to high energies before they are made to collide with each other or with stationary targets. Detectors observe and record the results of these collisions.

Founded in 1954, the CERN Laboratory sits astride the Franco–Swiss border near Geneva. It was one of Europe’s first joint ventures and now has 22 Member States.

Read more:

"Italian neutrino experiment to move to the US" – symmetry magazine:

Related links:

Fermi National Accelerator Laboratory:

Italian Institute for Nuclear Physics (INFN):

For more information about the European Organization for Nuclear Research (CERN), visit:

Image (mentioned), Text, Credits: CERN/Cian O'Luanaigh.


NASA RapidScat Proving Valuable for Tropical Cyclones

ISS - International Space Station patch.

April 22, 2015

The ISS-RapidScat instrument has been in orbit seven months, and forecasters are already finding this new eye-in-the-sky helpful as they keep watch on major storms around the globe.

RapidScat measures Earth's ocean surface wind speed and direction over open waters. The instrument's data on ocean winds provide essential measurements for researchers and scientists to use in weather predictions, including hurricane monitoring. The NASA instrument arrived at the International Space Station (ISS) on Sept. 23, 2014, providing a new resource for tracking and studying storms ranging from tropical cyclones to nor'easters. RapidScat has kept busy in 2015's already active Southern Hemisphere hurricane season and the Northern Hemisphere's winter storm season.

Graphic above: On Jan. 28, 2015 from 2:41 to 4:14 UTC, ISS-RapidScat saw the nor'easter's strongest sustained winds (red) between 56 and 67 mph (25 to 30 mps/90 to 108 kph) just off-shore from eastern Cape Cod.Credits: NASA JPL/Doug Tyler.

According to Bryan Stiles, lead for RapidScat science data processing at NASA's Jet Propulsion Laboratory, Pasadena, California, "RapidScat data is now used by meteorological agencies around the world, including the U.S. Navy, the National Oceanographic and Atmospheric Administration [NOAA], and the European Organization for the Exploitation of Meteorological Satellites, among others," he said. "Wind data obtained by RapidScat have been used by NOAA to detect gale force and storm force conditions and issue warnings to shipping. The wind data is available to both forecasters and scientists. RapidScat data is used to support real-time weather prediction and to improve the models scientists use to predict both short-term weather and long-term climate trends."

ISS - RapidScat. Animation Credit: NASA

From the space station, this orbiting scatterometer instrument uses radar pulses reflected from the ocean's surface from different angles to measure ocean surface roughness, which is then used to determine surface wind speed and direction. This vantage point, combined with the fact that the space station orbits Earth every 90 minutes, also allows RapidScat to provide observations on how ocean winds vary over the course of the day.

"Most Earth observing satellites are in polar, sun-synchronous orbits, meaning they observe the same locations at the same two local times of day with a regular repeating pattern," said Doug Tyler of the RapidScat team at JPL. "Because of the unique orbit of the space station, RapidScat observations occur at varying times of day with an irregular repeat period. RapidScat sometimes sees things several times in a row. The ISS orbit provided three overpasses of [Tropical Cyclone Nathan] in 23 hours, allowing RapidScat to capture changes in wind speed and direction as the storm developed."

ISS - RapidScat. Image Credit: NASA

The Joint Typhoon Warning Center (JTWC) forecasts tropical cyclones in several oceans and is also using ISS-RapidScat data. On March 15, 2015, at 0428 UTC, JTWC noted, "RapidScat showed that [Tropical Cyclone Nathan's] strongest winds (still assessed at 40 knots) remain in the northern periphery of the system, with significantly weaker winds in the southern portion." It's helpful to know where the strongest winds are in the system to enhance warnings, especially if they are affecting land or in a shipping channel.

The same week, RapidScat provided surface wind data on the most powerful tropical cyclone to affect the Southern Pacific island nation of Vanuatu. After Tropical Cyclone Pam became an extra-tropical cyclone and moved near New Zealand, RapidScat continued to provide the location and speed of the strongest surface winds, which assisted with warnings.

Earlier this year, RapidScat also provided wind data on a nor'easter that affected New England and triggered blizzard warnings on Jan. 27 and 28. The wind data captured on the intense system showed the strongest winds on the first day near 78 miles per hour (35 meters per second/126 kilometers per hour) as it moved along the coast, stretching from eastern Long Island, New York, to southern Nova Scotia, Canada.

For more information on RapidScat, visit: and

For more information about NASA's Earth science activities, visit:

Image (mentioned), Graphic (mentioned), Animation (mentioned), Text, Credits: NASA/Goddard Space Flight Center/Rob Gutro/JPL/Alan Buis.


First Exoplanet Visible Light Spectrum

ESO - European Southern Observatory logo.

22 April 2015

New technique paints promising picture for future

Artist’s impression of the exoplanet 51 Pegasi b

Astronomers using the HARPS planet-hunting machine at ESO’s La Silla Observatory in Chile have made the first-ever direct detection of the spectrum of visible light reflected off an exoplanet. These observations also revealed new properties of this famous object, the first exoplanet ever discovered around a normal star: 51 Pegasi b. The result promises an exciting future for this technique, particularly with the advent of next generation instruments, such as ESPRESSO, on the VLT, and future telescopes, such as the E-ELT.

The exoplanet 51 Pegasi b [1] lies some 50 light-years from Earth in the constellation of Pegasus. It was discovered in 1995 and will forever be remembered as the first confirmed exoplanet to be found orbiting an ordinary star like the Sun [2]. It is also regarded as the archetypal hot Jupiter — a class of planets now known to be relatively commonplace, which are similar in size and mass to Jupiter, but orbit much closer to their parent stars.

The star 51 Pegasi in the constellation of Pegasus

Since that landmark discovery, more than 1900 exoplanets in 1200 planetary systems have been confirmed, but, in the year of the twentieth anniversary of its discovery, 51 Pegasi b returns to the ring once more to provide another advance in exoplanet studies.

The team that made this new detection was led by Jorge Martins from the Instituto de Astrofísica e Ciências do Espaço (IA) and the Universidade do Porto, Portugal, who is currently a PhD student at ESO in Chile. They used the HARPS instrument on the ESO 3.6-metre telescope at the La Silla Observatory in Chile.

Wide-field view of the sky around the star 51 Pegasi

Currently, the most widely used method to examine an exoplanet’s atmosphere is to observe the host star’s spectrum as it is filtered through the planet’s atmosphere during transit — a technique known as transmission spectroscopy. An alternative approach is to observe the system when the star passes in front of the planet, which primarily provides information about the exoplanet’s temperature.

The new technique does not depend on finding a planetary transit, and so can potentially be used to study many more exoplanets. It allows the planetary spectrum to be directly detected in visible light, which means that different characteristics of the planet that are inaccessible to other techniques can be inferred.

Zooming in on 51 Pegasi

The host star’s spectrum is used as a template to guide a search for a similar signature of light that is expected to be reflected off the planet as it describes its orbit. This is an exceedingly difficult task as planets are incredibly dim in comparison to their dazzling parent stars.

The signal from the planet is also easily swamped by other tiny effects and sources of noise [3]. In the face of such adversity, the success of the technique when applied to the HARPS data collected on 51 Pegasi b provides an extremely valuable proof of concept.

Jorge Martins explains: “This type of detection technique is of great scientific importance, as it allows us to measure the planet’s real mass and orbital inclination, which is essential to more fully understand the system. It also allows us to estimate the planet’s reflectivity, or albedo, which can be used to infer the composition of both the planet’s surface and atmosphere.”

Artist’s impression of the exoplanet 51 Pegasi b

51 Pegasi b was found to have a mass about half that of Jupiter’s and an orbit with an inclination of about nine degrees to the direction to the Earth [4]. The planet also seems to be larger than Jupiter in diameter and to be highly reflective. These are typical properties for a hot Jupiter that is very close to its parent star and exposed to intense starlight.

HARPS was essential to the team’s work, but the fact that the result was obtained using the ESO 3.6-metre telescope, which has a limited range of application with this technique, is exciting news for astronomers. Existing equipment like this will be surpassed by much more advanced instruments on larger telescopes, such as ESO’s Very Large Telescope and the future European Extremely Large Telescope [5].

"We are now eagerly awaiting first light of the ESPRESSO spectrograph on the VLT so that we can do more detailed studies of this and other planetary systems,” concludes Nuno Santos, of the IA and Universidade do Porto, who is a co-author of the new paper.


[1] Both 51 Pegasi b and its host star 51 Pegasi are among the objects available for public naming in the IAU’s NameExoWorlds contest.

[2] Two earlier planetary objects were detected orbiting in the extreme environment of a pulsar.

[3] The challenge is similar to trying to study the faint glimmer reflected off a tiny insect flying around a distant and brilliant light.

[4] This means that the planet’s orbit is close to being edge on as seen from Earth, although this is not close enough for transits to take place.

[5] ESPRESSO on the VLT, and later even more powerful instruments on much larger telescopes such as the E-ELT, will allow for a significant increase in precision and collecting power, aiding the detection of smaller exoplanets, while providing an increase in detail in the data for planets similar to 51 Pegasi b.

More information:

This research was presented in a paper “Evidence for a spectroscopic direct detection of reflected light from 51 Peg b”, by J. Martins et al., to appear in the journal Astronomy & Astrophysics on 22 April 2015.

The team is composed of J. H. C. Martins (IA and Universidade do Porto, Porto, Portugal; ESO, Santiago, Chile), N. C. Santos (IA and Universidade do Porto), P. Figueira (IA and Universidade do Porto), J. P. Faria (IA and Universidade do Porto), M. Montalto (IA and Universidade do Porto), I. Boisse (Aix Marseille Université, Marseille, France), D. Ehrenreich (Observatoire de Genève, Geneva, Switzerland), C. Lovis (Observatoire de Genève), M. Mayor (Observatoire de Genève), C. Melo (ESO, Santiago, Chile), F. Pepe (Observatoire de Genève), S. G. Sousa (IA and Universidade do Porto), S. Udry (Observatoire de Genève) and D. Cunha (IA and Universidade do Porto).

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 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. 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 a major partner in ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre European Extremely Large Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.


Research paper:

Photos of La Silla:

ESO 3.6-metre telescope:

HARPS instrument:

ESO’s Very Large Telescope (VLT):

European Extremely Large Telescope (ELT):

Instituto de Astrofísica e Ciências do Espaço (IA):

Images, Text, Credits: ESO/M. Kornmesser/Nick Risinger ( and Sky & Telescope/Digitized Sky Survey 2/Videos: ESO/M. Kornmesser/Nick Risinger ( Sky Survey 2/A. Fujii. Music: Johan B. Monell (

Best regards,

Second Dragon, fruit flies and fresh coffee for Samantha

ESA - Futura Mission patch.

22 April 2015

ESA astronaut Samantha Cristoforetti is nearing the end of her six-month Futura mission but her action-packed stay on the International Space Station is showing no signs of slowing down.

Last Friday saw the arrival of the second Dragon cargo ferry for Samantha. She controlled the 16 m-long robot arm to grab the spacecraft and pull it to the Space Station with NASA astronaut Terry Virts providing support.

Dragon capture

Earlier this year, the Station was visited by a Dragon ferry with Samantha supporting NASA’s Butch Wilmore for the grappling and berthing.

The spacecraft has brought fresh supplies and experiments to the weightless research laboratory. Samantha has been performing experiments as diverse as studying fruit flies, investigating small particles in liquids, looking at microscopic worms and growing plants.

Working on Biolab

Science zoo

Fruit flies are a model organism for scientists and are studied extensively – they live for around a week and share many genes with humans. This experiment will chart gene changes over generations of fruit flies in space in relation to diseases.

Samantha has been looking at colloids – small particles suspended in liquids, found in milk and paint for example – for a NASA experiment to understand how they behave without gravity’s interference. This research ties in with ESA’s colloid experiments.

Nematode worm

Another common traveller on the Station and an often-studied animal for biologists is the Caenorhabditis elegans worm. Previous research has shown that the worm adapts and even thrives in weightlessness, implying that muscles might age less in space.

Samantha looked after the worms and stored generations for analysis in this Japanese-led experiment, as did ESA astronaut André Kuipers on his 2004 mission. This time, however, researchers are looking at changes in DNA over four generations.

Working on Triplelux experiment

Samantha has also been tending to plants for the Aniso Tubule study that is looking at their stems and how they grow in weightlessness compared to Earth. This research will help to grow food crops in space, which would be necessary for longer missions. The research has implications for crops on Earth because plants spend a lot of energy growing stalks. This energy could be diverted to increase production if we knew more about how the mechanisms work.

The latest Dragon spacecraft delivered the second part of ESA’s Triplelux experiment that is investigating the immune system of organisms on a cellular level. Samantha kicked off the Triplelux-B experiment earlier this year by recording how immune cells from the common blue mussel react to an infection. Samantha will continue the experiment now that a second set of samples from a rat’s immune system has arrived.

Samantha with new Dragon arrival

Time for coffee

These experiments are just some examples from the Station – read more about her work in Samantha’s logbook. Aside from her 40-hour-plus work week, she finds the time to take astounding pictures of our planet.

A special item on this week’s Dragon is the ‘ISSpresso’ machine that should offer a fresh brew of coffee for the Italian astronaut and her five crewmates. Spending months on the Station cut off from the world can be difficult, but a fresh cup of coffee can work wonders. Future capsules will extend the menu to include tea and soup.

Related links:

ESA astronaut André Kuipers on his 2004 mission:

ESA’s colloid experiments:

ESA’s Triplelux experiment:

Futura mission:

Agenzia Spaziale Italiana (ASI):

Connect with Samantha Cristoforetti:

Where is the International Space Station?:

Images, Text, Credits: ESA/NASA/Creative Commons ShareAlike license–B. Goldstein.