vendredi 4 juillet 2014

Newfound Frozen World Orbits in Binary Star System

NASA patch.

July 4, 2014

A newly discovered planet in a binary, or twin, star system located 3,000 light-years from Earth is expanding astronomers’ notions of where Earth-like -- and even potentially habitable -- planets can form, and how to find them.

At twice the mass of Earth, the planet orbits one of the stars in the binary system at almost exactly the same distance at which Earth orbits the sun.  However, because the planet’s host star is much dimmer than the sun, the planet is much colder than Earth -- a little colder, in fact, than Jupiter’s icy moon Europa.

Four international research teams, led by professor Andrew Gould of The Ohio State University in Columbus, published their discovery in the July 4 issue of the journal Science. The research is partly funded by NASA.

The study provides the first evidence that terrestrial planets can form in orbits similar to Earth’s, even in a binary star system where the stars are not very far apart. Although this planet itself is too cold to be habitable, the same planet orbiting a sun-like star in such a binary system would be in the so-called “habitable zone” -- the region where conditions might be right for life.

Image above: This artist's rendering shows a newly discovered planet (far right) orbiting one star (right) of a binary star system. Image Credit: Cheongho Han, Chungbuk National University, Rep. of Korea.

“This greatly expands the potential locations to discover habitable planets in the future,” said Scott Gaudi, professor of astronomy at Ohio State. “Half the stars in the galaxy are in binary systems. We had no idea if Earth-like planets in Earth-like orbits could even form in these systems.”

Earlier evidence that planets form in binary star systems came from NASA's Kepler and Spitzer space telescopes (see and, but the planets and dust structures in those studies were not similar to those of Earth.

The technique astronomers use to find the planet, called OGLE-2013-BLG-0341LBb, is called gravitational microlensing. In this method, the light of a distant star is magnified by a closer star that happens to pass in front -- if a planet is also present around the foreground star, it will further alter and distort the light of the background star. The telescopes used in this study are part of several projects, including the OGLE (Optical Gravitational Lensing Experiment), MOA (Microlensing Observations in Astrophysics), MicroFUN (the Microlensing Follow Up Network), and the Wise Observatory.

Searching for planets within binary systems is tricky for most techniques, because the light from the second star complicates the interpretation of the data. "But in gravitational microlensing,” Gould explained, "we don't even look at the light from the star-planet system. We just observe how its gravity affects light from a more distant, unrelated star. This gives us a new tool to search for planets in binary star systems."

Wide-Field Infrared Survey Telescope (WFIRST-AFTA). Image Credit: NASA

NASA's proposed WFIRST-AFTA (Wide-Field Infrared Survey Telescope - Astrophysics Focused Telescope Assets) mission would use the microlensing technique to find and characterize hundreds of thousands of planets in binary systems, website:

WFIRST: Uncovering the Mysteries of the Universe.

Video above: The Wide-Field Infrared Survey Telescope (WFIRST) is an upcoming space telescope designed to perform wide-field imaging and spectroscopy of the infrared sky. One of WFIRST's objectives will be looking for clues about dark energy--the mysterious force that is accelerating the expansion of the universe. Another objective of the mission will be finding and studying exoplanets. Video Credit: NASA Goddard Space Flight Center.

WFIRST uses the same 2.4 meter telescope size as Hubble, but with 18 cutting-edge fourth-generation image sensors compared to Hubble's single first-generation sensor. As a result, each WFIRST image will cover over 200 times as much as a Hubble Wide Field Camera 3/IR image and be 300 megapixels in size. Hubble images reveal thousands of galaxies; a single WFIRST image will uncover millions.

To help uncover the mystery of dark energy, WFIRST will make incredibly precise measurements of the universe. These measurements, like the distance and position of galaxies, can be compared to other measurements—such as the cosmic microwave background from the WMAP mission—to determine how dark energy has changed over time. WFIRST can also measure the slight distortions in light from distant galaxies as it passes more nearby mass concentrations. These data will build a three dimensional picture of how mass is distributed throughout the universe, and provide independent confirmation of its structure.

Because WFIRST has such a large and sensitive field of view, it can find thousands of new exoplanets through a process called microlensing. When one star in the sky appears to pass nearly in front of another, the light rays of the background source star become bent due to the gravitational "attraction" of the foreground star. This "lens" star is then a virtual magnifying glass, amplifying the brightness of the background source star. If the lens star harbors a planetary system, then those planets can also act as lenses, each one producing a short deviation in the brightness of the source. For closer planets, WFIRST will open a new era of direct observation. Currently only a handful of planets are observable in light reflected off of them, and they are all large planets close to their stars. WFIRST will be able to resolve planets as small as Neptune, and as far from their stars as Saturn is from the sun. This is possible thanks to newly developed coronagraphs, which block the bright light from the star to make the planet more visible.

Read the full news release from Ohio State at:

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


jeudi 3 juillet 2014

Rockot rocket orbited block spacecraft Messenger-M



Launch of Rockot rocket at Plesetsk cosmodrome

On July 3 at 16 hours 43 minutes Moscow time on state testing cosmodrome Ministry of Defence of the Russian Federation (Plesetsk cosmodrome) started launch (ILV) Rockot with the upper stage Breeze-KM and three spacecraft (SC) Messenger-M multifunctional system of personal satellite communication and data transmission (MSPSS).

Launch executed by combat crew specialists from the Ministry of Defense of the Russian Federation and representatives of the space industry.

Launch of three Gonets-M comsats on a Rokot from Plesetsk

In the estimated time block spacecraft Messenger-M (production - JSC Information Satellite Systems them. Academician Reshetnev) displayed on the target orbit.

Booster light class "Roar" and the upper stage Breeze-KM created at the State Research and Production Space Center. Khrunichev.

Rockot rocket description

Multifunction personal satellite communication system and data from the spacecraft in low orbits Messenger-D1M created under the Federal Space Program commissioned by Roscosmos and is able to solve the problem of providing personal communications and data of various types, including coordinate-time satellite data coordination system GLONASS.

Gonets-M communication satellite

Services, built on the basis of the Messenger solve the problem of monitoring the various infrastructures transmit navigation and timing data obtained by the GLONASS system, with moving objects in different dispatching centers and monitoring, as well as personal communications in remote areas.

ROSCOSMOS Press Release:

Images, Video, Text, Credits: Roscosmos press service / ROSCOSMOS / Translation: Aerospace.

Best regards,

STEREO Solar Conjunction

NASA - STEREO Mission logo.

July 3, 2014

Since February 2011, the two spacecraft of NASA's the Solar Terrestrial Relations Observatory or STEREO mission have been providing scientists with unprecedented views of the far side of the sun.

The spacecraft travel at different speeds. This means that over time, the satellites become increasingly out of sync, appearing from Earth's perspective to drift farther apart, able to observe first the sides and eventually the far side of the sun. Now they are nearing each other once again, this time on the other side of the sun. During this period when the sun blocks Earth's view -- a geometrical position known in astronomy as a superior conjunction -- radio receivers on Earth will not be able to distinguish STEREO's signal from the sun's radiation. Communication with the spacecraft will cease and the satellites will both go into safe mode without collecting data for a time.

STEREO Solar Conjunction

This will happen for STEREO-Ahead from March 24 to July 7, 2015. STEREO-Behind will be in superior conjunction from Jan. 22 to March 23, 2015. At least one spacecraft, therefore, will always be collecting data. Before this occurs, the heating from the sun will also begin to affect - though not shut down -- data collection. From wherever they are in space, the STEREO spacecraft aim their antenna toward Earth to send down data. This position puts the antenna fairly close to pointing at the sun, exposing the instruments to more heat than it can safely bear. The antenna can be adjusted to point in different directions, but the signal coming to Earth will be much fainter and won't allow for as much data to be downloaded.

This antenna adjustment will begin on Aug. 20, 2014, for the STEREO-Ahead spacecraft and on Dec. 1, 2014, for STEREO-Behind. During this phase, STEREO instruments will continue to run 24 hours a day, but they will gather lower-resolution data than usual. Some of this data will be downloaded whenever STEREO can link up with an Earth receiver. The rest of the data will be stored on board to be downloaded when the spacecraft reach a more auspicious geometrical position in early 2016. To test for this off-pointing from the sun, STEREO-Ahead will undergo tests and not be collecting data from July 6-12, 2014. The same tests will be performed on STEREO-Behind from Sept. 29 - Oct. 6, 2014.

STEREO spacecraft

Throughout this entire phase until 2016, at least one STEREO spacecraft will be capturing data at any one time, so scientists will have an uninterrupted record of events on the sun to coordinate with the observations of solar telescopes on the Earth side. Real time monitoring of the sun, its flares and coronal mass ejections - information used by the US National Oceanic and Atmospheric Administration to help forecast space weather -- will also continue via a fleet of NASA spacecraft closer to Earth.

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For more information about STEREO Mission, visit: and

Image, Video, Text, Credit: NASA's Goddard Space Center.


OCO-2 Takes the A-Train to Study Earth's Atmosphere

NASA - OCO-2 Mission logo.

July 03, 2014

Every day, above our planet, five Earth-observing satellites rush along like trains on the same "track," flying minutes, and sometimes seconds, behind one another. They carry more than 15 scientific instruments in total, looking at many different aspects of our home planet. Called the Afternoon Constellation, or A-Train, these satellites work as a united, powerful tool for advancing our understanding of Earth's surface and atmosphere.

Image above: OCO-2 will become the leader of the Afternoon Constellation, or A-Train, as shown in this artist's concept. Japan's Global Change Observation Mission - Water (GCOM-W1) satellite and NASA's Aqua, CALIPSO, CloudSat and Aura satellites follow. Image Credit: NASA.

The train is about to get longer. NASA's Orbiting Carbon Observatory-2 (OCO-2), which launched July 2, will be the A-Train's sixth member. Its mission is to measure atmospheric carbon dioxide, a greenhouse gas that makes up a greater percentage of our atmosphere today than it has in at least 800,000 years. It will produce data that will help scientists analyze data from the other A-Train instruments. In return, other satellites will help validate its vital data.

"The A-Train constellation is an ideal measurement system for us," said Dave Crisp, the leader of the OCO-2 science team at NASA's Jet Propulsion Laboratory in Pasadena, California.

OCO-2 will fly along the same path as NASA satellites CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation) and CloudSat, which monitor minute particles in the atmosphere called aerosols, and clouds, respectively. "We've lined up the ground tracks of OCO-2, CALIPSO and CloudSat almost perfectly, and we're hoping to keep them well aligned for as long as possible during the missions, so we can do the science we want with measurements from all three satellites," Crisp said.

OCO-2 measures carbon dioxide by observing its effect on sunlight. Sunlight is made up of waves of many lengths, or frequencies, some visible and others invisible. As sunlight passes through the atmosphere, carbon dioxide and other molecules absorb specific frequencies in the spectrum of light, leaving dark, narrow gaps in the spectrum. The more light that has been absorbed in a certain column of air, the more carbon dioxide is present there. In some cases, this may suggest that Earth's surface beneath that air contains a source of carbon dioxide, like a large industrial city. Less carbon dioxide implies a "sink," which absorbs carbon dioxide, like a thick forest during the growing season.

Image above: An artist's rendering of the atmospheric column OCO-2 will see and the sunlight it will examine for evidence of carbon dioxide. Carbon dioxide molecules, with two oxygen atoms and a carbon atom, are represented in red and black. Image Credit: NASA/JPL-Caltech.

The OCO-2 spacecraft carries a single instrument composed of three spectrometers that measure different regions of the spectrum of light. One of these spectrometers observes the spectrum of molecular oxygen, referred to as the A-band spectrum. This is important because molecular oxygen is a relatively constant fraction of the atmosphere and can be used as a reference for measurements of other atmospheric gases, such as carbon dioxide. In addition to being critical for calibrating the carbon dioxide concentrations, it also tells scientists how much sunlight is absorbed or reflected by the aerosols and clouds, features that CALIPSO and CloudSat observe.

"If we combine the A-band spectrometer's measurements with information on aerosols and clouds from CALIPSO and CloudSat, we can use that information to estimate the amount of absorption of sunlight by these airborne particles, which is something we cannot currently do," said Dave Winker, principal investigator for the CALIPSO mission.

CloudSat and CALIPSO also help clarify OCO-2's data. The observatory uses its A-band spectrometer to find out how far sunlight has traveled before it reaches the satellite (its optical path) -- vital information for finding sources and sinks. A tiny mistake in the path-length measurement can introduce serious errors in the satellite's carbon dioxide measurements. Often clouds and aerosols in Earth's atmosphere reflect some sunlight back toward space before it reaches the surface, shortening sunlight's path and confusing the spectrometer about the distance to Earth. But CALIPSO and CloudSat's data about the location and height of aerosols and clouds can verify OCO-2's path-length measurements and determine what kept the sun from reaching Earth's surface.

"To check OCO-2's accuracy, we can compare it to CloudSat and CALIPSO. These measurements are synergistic," Crisp said.

Winker noted, "From OCO-2's point of view, CALIPSO is going to be very important in validating their measurement by correcting for cloud and aerosol effects. That these two satellites are flying together is a key part of the mission."

The A-Train's other satellites support OCO-2's work, too. MODIS (Moderate Resolution Imaging Spectroradiometer), an instrument on the Aqua satellite, tracks cloud cover. AIRS (Atmospheric Infrared Sounder), another Aqua instrument, measures air temperature and the amount of water content in the atmosphere. To accurately measure carbon dioxide, scientists must know all those details.

"We have the platforms that can tell us about water vapor and temperature, as well as clouds from the CloudSat satellite, the CALIPSO satellite, the AIRS instrument, and the MODIS instrument. This is the right place to fly OCO-2," Crisp said.

For more information about OCO-2, visit these sites: and

NASA monitors Earth's vital signs from land, air and space with a fleet of satellites and ambitious airborne and ground-based observation campaigns. NASA develops new ways to observe and study Earth's interconnected natural systems with long-term data records and computer analysis tools to better see how our planet is changing. The agency shares this unique knowledge with the global community and works with institutions in the United States and around the world that contribute to understanding and protecting our home planet.

For more information about NASA's Earth science activities in 2014, visit:

Images (mentioned), Credits: NASA / JPL / Alan Buis, written by Rosalie Murphy, JPL Earth Science and Technology Directorate.


Comet Pan-STARRS Marches Across the Sky

NASA - NEOWISE Mission logo.

July 3, 2014

NEOWISE Spies Comet Pan-STARRS Against Galaxy Backdrop

Video above: NASA's NEOWISE mission captured a series of infrared images of comet C/2012 K1 -- also referred to as comet Pan-STARRS -- as it swept across our skies in May 2014. Image Credit: NASA/JPL-Caltech.

NASA's NEOWISE mission captured a series of pictures of comet C/2012 K1 -- also known as comet Pan-STARRS -- as it swept across our skies in May 2014.

The comet is named after the astronomical survey project called the Panoramic Survey Telescope and Rapid Response System in Hawaii, which discovered the icy visitor in May 2012.

Comet Pan-STARRS hails from the outer fringes of our solar system, from a vast and distant reservoir of comets called the Oort cloud.

The comet is relatively close to us -- it was only about 143 million miles (230 million kilometers) from Earth when this picture was taken. It is seen passing a much more distant spiral galaxy, called NGC 3726, which is about 55 million light-years from Earth, or 2 trillion times farther away than the comet.

Two tails can be seen lagging behind the head of the comet. The bigger tail is easy to see and is comprised of gas and smaller particles. A fainter, more southern tail, which is hard to spot in this image, may be comprised of larger, more dispersed grains of dust.

Image above: NASA's NEOWISE mission captured this series of pictures of comet C/2012 K1 -- also known as comet Pan-STARRS -- as it swept across our skies on May 20, 2014. Image Credit: NASA/JPL-Caltech.

Comet Pan-STARRS is on its way around the sun, with its closest approach to the sun occurring in late August. It was visible to viewers in the northern hemisphere through most of June. In the fall, after the comet swings back around the sun, it may be visible to southern hemisphere viewers using small telescopes.

The image was made from data collected by the two infrared channels on board the NEOWISE spacecraft, with the longer-wavelength channel (centered at 4.5 microns) mapped to red and the shorter-wavelength channel (3.4 microns) mapped to cyan. The comet appears brighter in the longer wavelength band, suggesting that the comet may be producing significant quantities of carbon monoxide or carbon dioxide.

Originally called the Wide-field Infrared Survey Explorer (WISE), the NEOWISE spacecraft was put into hibernation in 2011 after its primary mission was completed. In September 2013, it was reactivated, renamed NEOWISE and assigned a new mission to assist NASA's efforts to identify the population of potentially hazardous near-Earth objects. NEOWISE is also characterizing previously known asteroids and comets to better understand their sizes and compositions.

NASA's Jet Propulsion Laboratory, Pasadena, California, manages the NEOWISE mission for NASA's Near-Earth Object Observation Program of its Planetary Science Division in Washington. The Space Dynamics Laboratory in Logan, Utah, built the science instrument. Ball Aerospace & Technologies Corp. of Boulder, Colorado, 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.

More information on NEOWISE is online at: and

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


Galileo: it’s all about the time

ESA - Galileo Mission logo.

3 July 2014

Europe’s Galileo satellite navigation system – the combination of satellites in space and stations on the ground – forms a planetary scale timepiece. Current testing shows it keeping very good time indeed – around 10 billionths of a second on average.

To put that in perspective, light waves cover a distance equivalent to more than seven times around planet Earth in one second.

Galileo timing

So why does Galileo need to deliver such precise timing, down to this billionth-of-a-second scale?

Because light – and all other electromagnetic waves, including radio – travels at a fixed speed, just under 30 cm per nanosecond ( a billionth of a second), the time it takes for Galileo signals to reach a user receiver on the ground can be used to yield distance measurements. All the receiver has to do is multiply the travel time by the speed of light.

A minimum of four satellites need to be visible: one each to fix latitude, longitude and altitude, with another to ensure synchronised timings.

So such precise timing becomes essential for accurate positioning. Galileo’s initial four-satellite ‘In Orbit Validation’ testing demonstrates a horizontal accuracy of up to 3 m, 95% of the time, set to improve as more satellites join the system later this year.

How satnav works

In addition, the Galileo System Time (GST) made available through satellite signals is set to become an important utility in its own right, essential to synchronise worldwide banking, power and data networks and a boon for scientific teams.

The challenge has been to maintain GST in a stable manner. Determining GST would, of course, be impossible without the latest high-performance atomic clocks, which use an atom’s switching between tightly-defined energy states for their ‘ticks’.

Ground-based atomic clocks

Because all atoms of a given element and isotope are identical they produce precisely the same high-frequency microwave response when transitioning between states, typically on the order of billions of times per second.

GST is determined using a set of active hydrogen maser atomic clocks at Galileo’s Precise Timing Facility, at Fucino in Italy. The averaged output of these cupboard-sized clocks establish the reference time for the entire Galileo system.

Galileo satellites in space

The satellites themselves house smaller, less accurate rubidium and passive hydrogen maser atomic clocks, the latter being about the size of office fridges. These two designs keep an accuracy of three seconds in one million years and one second in three million years, respectively, though this is not enough by itself to maintain the ultrahigh precision needed.

Corrections are therefore transmitted from the ground on a regular basis, at least once every 100 minutes once the system becomes fully operational, to keep these satellite clocks fully in line with GST.

In addition, while GST itself is determined on a fully independent basis, it is also required to be kept in strict agreement with the international reference time, Universal Time Coordinated or UTC.

Galileo time compared to UTC

This is achieved by continuously comparing GST with the national real time approximations of UTC carried out by  France, Germany, Italy, Spain and Sweden.

The current ‘offset’ between GST and the approximation of UTC (the final measurement of UTC is so precise it is actually calculated weeks afterwards) is determined by Galileo’s Time Validation Facility (the precursor of the Galileo Time Service Provider), which is currently operated by the company GMV in Madrid, Spain.

This process means UTC time measurements can also be made available to users to within an designed accuracy of 26 nanoseconds, although in practice Galileo has been able to do better than this – down to about 5–10 nanoseconds.

Galileo's UTC compared to 'actual'' UTC

Finally, GST also needs to be kept in synch with time system underpinning the US GPS system, known as GPS Time.

To enable user receivers to employ both Galileo and GPS in a seamless manner, the current offset between the two reference times needs to be determined and passed to users through the navigation signal, to an accuracy of 5 nanoseconds or less.

It is officially known as the GPS to Galileo time offset, GGTO. Without it, around 50 nanoseconds’ worth of difference between the two system’s reference times could put users up to 15 m out of place.

Working closely with the US Naval Observatory, which oversees GPS Time, Galileo’s Precise Timing Facility calculates GGTO continuously, the results being distributed through Galileo’s navigation message.

Galileo works, and works well

The current quartet of satellites make Galileo time measurements from at least one satellite possible around two thirds of the time to users.

The launch of two more Galileo satellites, set for this August, will lead to worldwide Galileo timing capability for users at almost all times.

Related links:

Galileo and GPS ‘synchronise watches’: new time offset helps working together:

Galileo starts to tell UTC, the world’s time:

Galileo IOV phase information sheet:

Images, Text, Credits: ESA / Anneke Le Floc'h / P. Carril / Airbus Defence & Space.

Best regards,

mercredi 2 juillet 2014

NASA Satellite Spots Heavy Rain Around Arthur's Center

NASA - Tropical Rainfall Measuring Mission (TRMM) logo.

July 2, 2014

NASA's TRMM Satellite Spots Heavy Rainfall Around Tropical Storm Arthur's Center

Image above: One of the Expedition 40 crew members aboard the Earth-orbiting International Space Station, some 227 nautical miles above Earth, photographed this image of Tropical Storm Arthur early on July 2, 2014. Image Credit: NASA.

Tropical Storm Arthur appears to be ramping up, and NASA's Tropical Rainfall Measuring Mission or TRMM satellite spotted heavy rainfall occurring around the storm's center on July 1 when it was centered over the Bahamas.

Those heavy rains are expected to affect the southern U.S. coastline over the next several days as the National Hurricane Center expects Arthur to strengthen into a hurricane. On July 2, the NHC issued a Hurricane Watch for Bogue Inlet to Oregon Inlet, North Carolina and Pamlico Sound. In addition, a Tropical Storm Watch is in effect for the east coast of Florida from Sebastian Inlet to Flagler Beach, South Santee River South Carolina to south of  Bogue Inlet, North Carolina,  north of Oregon Inlet, North Carolina to the North Carolina/Virginia Border, and the Eastern Albemarle Sound.

Image above: GOES-West image of Arthur. Image Credit: NOAA/NASA GOES Project.

The TRMM satellite had a good daylight look at tropical storm Arthur on July 1, 2014 at 1620 UTC (12:20 p.m. EDT) less than two hours after it was upgraded from a tropical depression. At NASA's Goddard Space Flight Center in Greenbelt, Maryland rainfall from TRMM's Microwave Imager (TMI) and Precipitation Radar (PR) data were overlaid on a GOES-East satellite infrared/visible image taken at 1626 UTC (12:26 p.m. EDT). The TMI instrument showed very heavy rainfall around Arthur's center. The heaviest rainfall was occurring at a rate of about 2 inches per hour. Powerful thunderstorms in that area reached heights above 15.5 km (about 9.6 miles).

Shortly after TRMM flew over Arthur and gathered rainfall and cloud height data, NASA's Terra satellite captured a visible image of the storm over the Bahamas. The image, created by the NASA Goddard MODIS Rapid Response Team, used visible data from the Moderate Resolution Imaging Spectroradiometer instrument that flies aboard Terra. The image showed a concentration of powerful storms around the center and northwestern quadrant of the storm. Arthur's western quadrant continued to affect the east coast of Florida.

Image above: NASA's Terra satellite captured this visible image of Tropical Storm Arthur on July 1 at 16:30 UTC (12:30 p.m. EDT) over the Bahamas. Image Credit: NASA Goddard MODIS Rapid Response Team.

On July 2 at 8 a.m. EDT (12:00 UTC) the center of Tropical Storm Arthur was near latitude 28.8 north and longitude 79.0 west. That's about 100 miles (160 km east-northeast of Cape Canaveral, Florida and NASA's Kennedy Space Center. Arthur's center is also 275 miles (445 km) south of Charleston, South Carolina.

The National Hurricane Center (NHC) noted that Arthur is moving toward the north near 6 mph (9 kph) and this motion is expected to continue today. A turn toward the north-northeast is expected tonight, July 2, followed by a turn toward the northeast. Maximum sustained winds remain near 60 mph (95 kph). Some strengthening is forecast during the next two days and Arthur is expected to become a hurricane by Thursday, July 3.

Image above: This image of rainfall occurring in Tropical Storm Arthur on July 1, 2014 at 12:20 p.m. EDT showed heavy rain (red) around the center of the storm. Image Credit: NASA/SSAI, Hal Pierce.

NHC noted that Arthur is expected to move east of the east-central coast of Florida today, July 2, pass east of Northeastern Florida tonight, move parallel to the coast of South Carolina on Thursday July 3, and approach the hurricane watch area Thursday night. For expected conditions along the watch areas, please visit the National Hurricane Center website:

July 01, 2014 - Atlantic's Developing Tropical Depression 1

On June 29, 2014, at 7:06 p.m. EDT (2306 UTC) the Tropical Rainfall Measuring Mission, or TRMM, satellite flew over a low-pressure center east of Florida. This low-pressure area developed over South Carolina and moved east into the Atlantic Ocean where the warm waters of the Gulf Stream helped fuel it.

NASA's TRMM satellite uses different instruments that allow scientists on Earth to create 3-D images of those storms so they can see where the most powerful areas are within it. A NASA rainfall analysis made on June 29 that used data from TRMM's Microwave Imager and Precipitation Radar (PR) instruments showed that rainfall was only light to moderate near the center of the low.

Image above: The MODIS instrument aboard NASA's Aqua satellite captured this visible image of Tropical Depression 1 (01L) off the coast of central Florida on June 30 at 3 p.m. EDT. Image Credit: NASA Goddard MODIS Rapid Response Team.

At NASA's Goddard Space Flight Center in Greenbelt, Maryland, the TRMM science office also created a simulated 3-D view of rainfall using TRMM PR data that showed most of the convective (rising air that forms clouds and thunderstorms) showers and thunderstorms near the center of the low were only reaching altitudes of about 6.2 miles (about 10 km). A few of the outer rain bands contained powerful thunderstorm "hot towers," or towering clouds that reached heights of about 8 miles (13 km) indicating strong thunderstorms with heavy rainfall potential.

On June 30 at 3 p.m. EDT the Moderate Resolution Imaging Spectroradiometer instrument aboard NASA's Aqua satellite captured an impressive visible image of Tropical Depression 1 off the coast of central Florida. The image showed some powerful, high thunderstorms over the Bahamas. In visible imagery, the strongest thunderstorms are identified as the highest ones that cast shadows on the clouds below them.

On July 1 that area of low pressure developed into Tropical Depression 1. The National Hurricane Center issued a Tropical Storm Watch for the east coast of Florida from Fort Pierce to Flagler Beach.

Image above: NASA's TRMM satellite showed showers and thunderstorms near the center of the low near 6.2 miles. A few of the outer rain bands contained thunderstorms as high as 8 miles (red) indicating strong storms with heavy rainfall potential. Image Credit: NASA/Hal Pierce, SSAI.

The National Hurricane Center (NHC) noted at 8 a.m. EDT (1200 UTC) that the center of Tropical Depression 1 was located near 27.5 degrees north latitude and 79.2 degrees west longitude. That's just about 95 miles (155 km) southeast of Cape Canaveral, Florida. The depression has remained nearly stationary during the past few hours. A northwestward motion is expected to begin later today, followed by a turn toward the north on Wednesday. Maximum sustained winds are near 35 mph (55 kph). The estimated minimum central pressure is 1007 millibars.

NHC noted that the depression may become a tropical storm later in the day on July 1.   The system is forecast to pass east of northeastern Florida on Wednesday, July 2. For updates, visit the National Hurricane Center webpage:

For more information about Tropical Rainfall Measuring Mission (TRMM), visit:

Images (mentioned), Text, Credits: NASA's Goddard Space Flight Center / Rob Gutro and Hal Pierce.


Ocean on Saturn Moon Could be as Salty as the Dead Sea

NASA / ESA - Cassini-Huygens Mission to Saturn & Titan patch.

July 2, 2014

Scientists analyzing data from NASA’s Cassini mission have firm evidence the ocean inside Saturn's largest moon, Titan, might be as salty as the Earth's Dead Sea.

The new results come from a study of gravity and topography data collected during Cassini's repeated flybys of Titan during the past 10 years. Using the Cassini data, researchers presented a model structure for Titan, resulting in an improved understanding of the structure of the moon's outer ice shell. The findings are published in this week’s edition of the journal Icarus.

"Titan continues to prove itself as an endlessly fascinating world, and with our long-lived Cassini spacecraft, we’re unlocking new mysteries as fast as we solve old ones," said Linda Spilker, Cassini project scientist at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, who was not involved in the study.

Additional findings support previous indications the moon's icy shell is rigid and in the process of freezing solid. Researchers found that a relatively high density was required for Titan's ocean in order to explain the gravity data. This indicates the ocean is probably an extremely salty brine of water mixed with dissolved salts likely composed of sulfur, sodium and potassium. The density indicated for this brine would give the ocean a salt content roughly equal to the saltiest bodies of water on Earth.

Image above: Researchers found that Titan's ice shell, which overlies a very salty ocean, varies in thickness around the moon, suggesting the crust is in the process of becoming rigid. Image Credit: NASA/JPL/SSI/Univ. of Arizona/G. Mitri/University of Nantes.

"This is an extremely salty ocean by Earth standards," said the paper's lead author, Giuseppe Mitri of the University of Nantes in France. "Knowing this may change the way we view this ocean as a possible abode for present-day life, but conditions might have been very different there in the past."

Cassini data also indicate the thickness of Titan's ice crust varies slightly from place to place. The researchers said this can best be explained if the moon's outer shell is stiff, as would be the case if the ocean were slowly crystalizing, and turning to ice. Otherwise, the moon's shape would tend to even itself out over time, like warm candle wax. This freezing process would have important implications for the habitability of Titan's ocean, as it would limit the ability of materials to exchange between the surface and the ocean.

A further consequence of a rigid ice shell, according to the study, is any outgassing of methane into Titan's atmosphere must happen at scattered "hot spots" -- like the hot spot on Earth that gave rise to the Hawaiian Island chain. Titan's methane does not appear to result from convection or plate tectonics recycling its ice shell.

Cassini spacecraft. Image Credit: NASA/JPL-Caltech

How methane gets into the moon's atmosphere has long been of great interest to researchers, as molecules of this gas are broken apart by sunlight on short geological timescales. Titan's present atmosphere contains about five percent methane. This means some process, thought to be geological in nature, must be replenishing the gas. The study indicates that whatever process is responsible, the restoration of Titan's methane is localized and intermittent.

"Our work suggests looking for signs of methane outgassing will be difficult with Cassini, and may require a future mission that can find localized methane sources," said Jonathan Lunine, a scientist on the Cassini mission at Cornell University, Ithaca, New York, and one of the paper's co-authors. "As on Mars, this is a challenging task."

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL manages the mission for NASA's Science Mission Directorate in Washington.

For more information about Cassini, visit: and and

Images (mentioned), Text, Credits: NASA / Dwayne Brown / JPL / Preston Dyches.


Galactic Pyrotechnics on Display

NASA - Chandra X-ray Observatory patch.

July 2, 2014

A galaxy about 23 million light years away is the site of impressive, ongoing fireworks. Rather than paper, powder and fire, this galactic light show involves a giant black hole, shock waves and vast reservoirs of gas.

This galactic fireworks display is taking place in NGC 4258, also known as M106, a spiral galaxy like the Milky Way. This galaxy is famous, however, for something that our galaxy doesn’t have – two extra spiral arms that glow in X-ray, optical and radio light. These features, or anomalous arms, are not aligned with the plane of the galaxy, but instead intersect with it.

The anomalous arms are seen in this new composite image of NGC 4258, where X-rays from NASA’s Chandra X-ray Observatory are blue, radio data from the NSF’s Karl Jansky Very Large Array are purple, optical data from NASA’s Hubble Space Telescope are yellow and infrared data from NASA’s Spitzer Space Telescope are red.

A new study made with Spitzer shows that shock waves, similar to sonic booms from supersonic planes, are heating large amounts of gas – equivalent to about 10 million suns. What is generating these shock waves? Researchers think that the supermassive black hole at the center of NGC 4258 is producing powerful jets of high-energy particles. These jets strike the disk of the galaxy and generate shock waves. These shock waves, in turn, heat the gas – composed mainly of hydrogen molecules – to thousands of degrees.

The Chandra X-ray image reveals huge bubbles of hot gas above and below the plane of the galaxy. These bubbles indicate that much of the gas that was originally in the disk of the galaxy has been heated and ejected into the outer regions by the jets from the black hole.

NASA's Chandra X-ray Observatory spacecraft

The ejection of gas from the disk by the jets has important implications for the fate of this galaxy. Researchers estimate that all of the remaining gas will be ejected within the next 300 million years – very soon on cosmic time scales – unless it is somehow replenished. Because most of the gas in the disk has already been ejected, less gas is available for new stars to form. Indeed, the researchers used Spitzer data to estimate that stars are forming in the central regions of NGC 4258, at a rate which is about ten times less than in the Milky Way galaxy.

The European Space Agency’s Herschel Space Observatory was used to confirm the estimate from Spitzer data of the low star formation rate in the central regions of NGC 4258. Herschel was also used to make an independent estimate of how much gas remains in the center of the galaxy. After allowing for the large boost in infrared emission caused by the shocks, the researchers found that the gas mass is ten times smaller than had been previously estimated.

Because NGC 4258 is relatively close to Earth, astronomers can study how this black hole is affecting its galaxy in great detail. The supermassive black hole at the center of NGC 4258 is about ten times larger than the one in the Milky Way and is consuming material at a faster rate, potentially increasing its impact on the evolution of its host galaxy.

These results were published in the June 20, 2014 issue of The Astrophysical Journal Letters and are available online. The authors are Patrick Ogle, Lauranne Lanz and Philip Appleton from the California Institute of Technology in Pasadena, California.

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

The Astrophysical Journal Letters,  June 20, 2014 issue:

View large image:

Chandra on Flickr:

For more information about Chandra X-ray Observatory, visit:

Images, Text, Credits: X-ray: NASA/CXC/Caltech/P.Ogle et al; Optical: NASA/STScI; IR: NASA/JPL-Caltech; Radio: NSF/NRAO/VLA.


A Stellar Womb Shaped and Destroyed by its Ungrateful Offspring

ESO - European Southern Observatory logo.

2 July 2014

The Gum 15 star formation region

The little-known cloud of cosmic gas and dust called Gum 15 is the birthplace and home of hot young stars. Beautiful and deadly, these stars mould the appearance of their mother nebula and, as they progress into adulthood, will eventually also be the death of her.

This image was taken as part of  the ESO Cosmic Gems programme [1] using the Wide Field Imager on the MPG/ESO 2.2-metre telescope at the La Silla Observatory in Chile. It shows Gum 15, located in the constellation of Vela (The Sails), some 3000 light-years from Earth [2]. This glowing cloud is a striking example of an HII region [3]. Such clouds form some of the most spectacular astronomical objects we can see; for example the Eagle Nebula (which includes the feature nicknamed “The Pillars of Creation”), the great Orion Nebula, and this less famous example, Gum 15.

Gum 15 in the constellation of Vela

Hydrogen (H) is the most common element in the Universe, and can be found in virtually every environment investigated by astronomers. HII regions are different because they contain substantial amounts of ionised hydrogen — hydrogen atoms that have been stripped of their electrons through high energy interactions with ultraviolet photons — particles of light. As the ionised hydrogen nuclei recapture electrons they release light at different characteristic wavelengths. It is one of these that gives nebulae such as Gum 15 their reddish glow — a glow which astronomers call hydrogen alpha (Hα).

A wide-field view of the Gum 15 star formation region

In HII regions the ionising photons come from the young hot stars within the region, and Gum 15 is no exception. At the centre of this image you can see one of the culprits: the star HD 74804, the brightest member of a cluster of stars known as Collinder 197.

Zooming in on Gum 15

The clumpy, irregular appearance that enhances this nebula’s beauty is not unusual for a HII region and is again a result of the stars within. HII regions have diverse shapes because the distribution of stars and gas inside them is so irregular. Adding to Gum 15’s interesting shape are the forked dark patch of obscuring dust visible in the centre of this image and some dim blue reflection structures crossing it. This dust feature makes the nebula resemble a larger and fainter version of the better known Trifid Nebula (Messier 20), although in this case the name Bifid Nebula might be more apposite.

Panning across the star formation region Gum 15

An HII region like this one might give birth to thousands of stars over a period of several million years. Some of these stars cause it to glow and sculpt its shape, and it is these stars that will eventually destroy it. Once the newly minted stars have passed through their infant stages, strong winds of particles will stream away from these large stars, sculpting and dispersing the gases around them, and when the most massive of these stars begin to die, Gum 15 will die with them. Some stars are so large that they will go out with a bang, exploding as supernovae and dispersing the regions last traces of HII, leaving behind just a cluster of infant stars.


[1] The ESO Cosmic Gems programme is an initiative to produce images of interesting, intriguing or visually attractive objects using ESO telescopes, for the purposes of education and public outreach. The programme makes use of telescope time that cannot be used for science observations. All data collected may also be suitable for scientific purposes, and are made available to astronomers through ESO’s science archive.

[2] The name of this object comes from the Australian astronomer Colin Gum, who published a catalogue of HII regions in 1955.

[3] HII regions (pronounded “aitch-two”) are large clouds of gas and dust that are host to bursts of star formation and homes to infant stars.

More information:

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”.


Photos of the MPG/ESO 2.2-metre telescope:

Other photos taken with the MPG/ESO 2.2-metre telescope:

Photos of La Silla:

Images, Text, Credits: ESO / IAU and Sky & Telescope / Digitized Sky Survey 2. Acknowledgement: Davide De Martin / Videos: ESO/Digitized Sky Survey 2/Nick Risinger ( Music: movetwo. Acknowledgement: Davide De Martin.

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OCO-2 Lifts Off on Carbon-Counting Mission

NASA - OCO-2 Mission logo.

July 2, 2014

Image above: A Delta II rocket leaps off the launch pad to begin NASA's OCO-2 mission at Vandenberg Air Force Base in California. Image Credit: NASA/Bill Ingalls.

A Delta II rocket blazed off the launch pad at Vandenberg Air Force Base in California early Wednesday morning to begin a landmark mission to survey carbon dioxide gas in Earth's atmosphere.

NASA's Orbiting Carbon Observatory-2, or OCO-2, is expected to provide insight into how the planet adjusts to the increased production of carbon dioxide from a vantage point in orbit that will allow it to take readings on a scale never achieved before.

Liftoff of OCO-2

While ground stations have been monitoring carbon dioxide concentrations, OCO-2 will be the first spacecraft to conduct a global-scale reading over several seasons. The spacecraft is expected to produce detailed readings to provide regional sources of carbon dioxide as well as sinks for the greenhouse gas.

"There's quite a lot of urgency to see what we can get from a satellite like OCO-2," said David Crisp, the science team lead for the mission.

The spacecraft flew into orbit aboard a United Launch Alliance Delta II rocket launched from Vandenberg Air Force Base in California. The July 2 liftoff came at 5:56 a.m. Eastern time, 2:56 Pacific time. The hexagonal spacecraft is about 6 feet long and 3 feet in diameter and weighs 985 pounds. The Delta II first stage's single liquid-fueled engine ignited moments before the three solid-fueled boosters roared to life to catapult the rocket and spacecraft off the pad toward space.

OCO-2 to Shed Light on Global Carbon Cycle

The launch was from the west coast so the spacecraft could enter a polar orbit of the Earth, a flight path that will see it cross over the Arctic and Antarctic regions during each revolution and get a complete picture of the Earth. It will fly about 438 miles above the planet's surface to take its readings.

"The only way to accomplish a polar orbit from U.S. soil is to launch from Vandenberg," said Tim Dunn, NASA's launch manager for the flight.

The mission is the first of its kind in the agency's extensive history of Earth-observing spacecraft. The spacecraft was launched to replace the first OCO that did not make it into orbit due to an anomaly in February 2009. The spacecraft carries one instrument and its sole focus is detecting carbon dioxide and watching from space as the Earth "breathes" to see what becomes of the gas.

The instrument is precise enough that researchers will be able to count the number of carbon dioxide molecules in the layers of the atmosphere and use the data to draw conclusions about how the increasing amount of gas will affect things like the global temperature. OCO-2's mission is to last at least two years.

Image above: Technicians and engineers work with the OCO-2 spacecraft during processing inside a facility at Vandenberg Air Force Base in California. Image Credit: NASA/Air Force 30th Space Wing.

NASA's Launch Services Program, based at Kennedy Space Center in Florida, managed the launch preparation and flight into orbit. The OCO-2 mission is handled by the Jet Propulsion Laboratory in California.

"We've been preparing for the OCO-2 mission for almost two years now," Dunn said before launch. "The biggest challenge has been in bringing the Delta II launch vehicle out of retirement. The last time we launched on a Delta II was October 2011, a weather satellite."

NASA's OCO-2 satellite in orbit. Image Credit: NASA / JPL

The Delta II has been one of NASA's most reliable launchers ever, registering more than 150 launches for NASA, the Air Force and commercial satellite makers from 1989 to 2011.

The launch team has been visiting Vandenberg during the preparation and spent the two weeks before launch there, running through the last phases of processing and countdown rehearsals.

With the mission safely begun, Dunn congratulated the team soon after OCO-2 separated from the Delta II's second stage and opened its pair of solar array wings.

For more information about NASA's Earth science activities in 2014, visit:

For more information about OCO-2, visit:

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Images (mentioned), Video, Text, Credits: NASA TV / NASA's Kennedy Space Center / Steven Siceloff.


mardi 1 juillet 2014

Cassini Names Final Mission Phase Its 'Grand Finale'

NASA / ESA - Cassini Mission to Saturn patch.

1 July 2014

With input from more than 2,000 members of the public, team members on NASA's Cassini mission to Saturn have chosen a name for the final phase of the mission: the Cassini Grand Finale.

Starting in late 2016, the Cassini spacecraft will begin a daring set of orbits that is, in some ways, like a whole new mission. The spacecraft will repeatedly climb high above Saturn's north pole, flying just outside its narrow F ring. Cassini will probe the water-rich plume of the active geysers on the planet's intriguing moon Enceladus, and then will hop the rings and dive between the planet and innermost ring 22 times.

Image above: With help from the public, members of NASA's Cassini mission have chosen to call the spacecraft's final orbits the "Cassini Grand Finale." Image Credit: NASA/JPL-Caltech.

Because the spacecraft will be in close proximity to Saturn, the team had been calling this phase "the proximal orbits," but they felt the public could help decide on a more exciting moniker. In early April, the Cassini mission invited the public to vote on a list of alternative names provided by team members or to suggest ideas of their own.

"We chose a name for this mission phase that would reflect the exciting journey ahead while acknowledging that it's a big finish for what has been a truly great show," said Earl Maize, Cassini project manager at NASA's Jet Propulsion Laboratory in Pasadena, California.
For more information about the name contest, visit:

For a visualization of the Grand Finale, visit: and click on "Cassini's Tour"

For more information about Cassini mission, Visit: and

Image (mentioned), Text, Credits: NASA / JPL / Preston Dyches.


Spot the Space Station looking at you

ESA - Blue Dot Mission patch.

1 July 2014

Moonrise from space

ESA astronaut Alexander Gerst and five astronauts from America and Russia are flying on the International Space Station 400 km above us – but did you know they are sharing live views of our planet and you can even see their home at night?

Circling Earth at 28 800 km/h, it takes only 90 minutes to complete a circuit of our planet – while cameras transmit the incredible view for everybody to see.

Find out where the Station is and enjoy the same views as the astronauts by visiting ESA’s Space Station tracker. The orbital outpost flies over the planet between latitudes 52ºN/S, reaching from the tip of South America to the UK.

Southern tip of South America

As it skims overhead, it looks like a bright star travelling smoothly across the heavens. Unlike aircraft, though, its light holds steady and it will always appear from the west and head eastwards.

ESA’s app for Apple smartphones and tablets keeps you updated on the trajectories of all ESA satellites, including the Space Station. Alternatively go to NASA's Spot the Station website and enter your city to receive alerts of when it next flies over your area.

Share the view

Taking a picture as the astronauts streak through the night sky is not difficult. Keep your camera steady on a tripod and make sure your exposure time is more than 30 seconds. If all goes well, you should capture a white streak that is the Station flying at 23 times the speed of sound.

Station over Darmstadt

Make the picture more interesting by framing a landmark in the foreground and share your creation with the world. Tweet the image with the hashtag #SpotTheStation with the location in brackets such as {Berlin, Germany} and your image will automatically be added to an interactive map.

A window on the world

Spot the Station is a joint project by NASA, Esri, the Canadian Centre of Geographic Sciences and Alexander’s crewmate Reid Wiseman. The locations and images will be collected throughout their mission until Alexander, Reid and commander Maxim Suraev return to Earth in November.

Space Station over Earth

Get your camera ready, look up and hope for cloudless nights.

Related links:

ESA’s Space Station tracker:

ESA’s app for Apple smartphones and tablets:

NASA's Spot the Station website:

All about Blue Dot:

Blue Dot blog:

Connect with Alexander Gerst:

Images, Text, Credits: ESA / NASA / Michael Khan.