Wednesday, February 26, 2014

NASA MIRI Installation on Webb Telescope - Time-lapse Video

This video shows a time-lapse of the install of the James Webb Space Telescope's Mid-Infrared Instrument in a clean room at NASA's Goddard Space Flight Center in Greenbelt, Md. The actual installation took about four hours.

The four science instruments that will fly aboard NASA's James Webb Space Telescope (JWST) have to be surgically installed for precision and accuracy.

NASA has just released a time-lapse video showing how clean room engineers installed one of those instruments into a large component of the JWST.

The Mid-Infrared Instrument (MIRI), arrived at NASA's Goddard Space Flight Center in Greenbelt, Md., May 28, 2012, and has undergone inspection and testing.

Recently, it was integrated into Webb's science instrument payload known as the Integrated Science Instrument Module (ISIM).

The ISIM will house the Webb's four main instruments.

The time-lapse video covers a period of four hours and was filmed in the largest clean room at Goddard, where all four of the Webb telescope's instruments and mirrors currently reside.

Viewers of the video will see engineers in clean room suits installing the MIRI over time.

"Actual total time to install the MIRI was just over four hours," said Jason Hylan, lead mechanical systems, mechanical integration and test, and opto-mechanical engineer for the ISIM at Goddard.

"The MIRI had to be positioned to a tolerance of 25 microns, or one one-thousandth of an inch, which is less than the width of a human hair."

MIRI will allow scientists to study cold and distant objects in greater detail than ever before.

MIRI will observe light with wavelengths in the mid-infrared range of 5 microns to 28 microns, which are longer wavelengths than human eyes can detect and even beyond the 0.6 micron to 5 micron wavelength range of Webb's other three instruments.

MIRI's capabilities will allow it to observe older, cooler stars in very distant galaxies, unveil newly forming stars within our Milky Way, find signatures of the formation of planets around stars other than our own, and record images and spectra of planets, comets and the outermost bits of debris in our solar system.

MIRI's mid-infrared coverage will complement the near-infrared capabilities of the other instruments, including observations of the most distant objects to help determine whether or not they are among the first ones that formed in the universe.

Herschel: SMA unveils how small cosmic seeds in Snake nebula grow into big stars

These two panels show the Snake nebula as photographed by the Spitzer and Herschel space telescopes

At mid-infrared wavelengths (the upper panel taken by Spitzer), the thick nebular material blocks light from more distant stars. 

At far-infrared wavelengths, however (the lower panel taken by Herschel), the nebula glows due to emission from cold dust. 

The two boxed regions, P1 and P6, were examined in more detail by the Submillimeter Array

Credit: Spitzer /GLIMPSE /MIPS, Herschel /HiGal, Ke Wang, European Southern Observatory

New images from the Smithsonian's Submillimeter Array (SMA) telescope provide the most detailed view yet of stellar nurseries within the Snake nebula.

These images offer new insights into how cosmic seeds can grow into massive stars.

Stretching across almost 100 light-years of space, the Snake nebula is located about 11,700 light-years from Earth in the direction of the constellation Ophiuchus.

In images from NASA's Spitzer Space Telescope it appears as a sinuous, dark tendril against the starry background. It was targeted because it shows the potential to form many massive stars (stars heavier than 8 times our Sun).

"To learn how stars form, we have to catch them in their earliest phases, while they're still deeply embedded in clouds of gas and dust, and the SMA is an excellent telescope to do so," explained lead author Ke Wang of the European Southern Observatory (ESO), who started the research as a predoctoral fellow at the Harvard-Smithsonian Center for Astrophysics (CfA).

The team studied two specific spots within the Snake nebula, designated P1 and P6. Within those two regions they detected a total of 23 cosmic "seeds" - faintly glowing spots that will eventually birth one or a few stars.

The seeds generally weigh between 5 and 25 times the mass of the Sun, and each spans only a few thousand astronomical units (the average Earth-Sun distance).

The sensitive, high-resolution SMA images not only unveil the small seeds, but also differentiate them in age.

Previous theories proposed that high-mass stars form within very massive, isolated "cores" weighing at least 100 times the mass of the Sun.

These new results show that that is not the case. The data also demonstrate that massive stars aren't born alone but in groups.

"High-mass stars form in villages," said co-author Qizhou Zhang of the CfA. "It's a family affair."

The team also was surprised to find that these two nebular patches had fragmented into individual star seeds so early in the star formation process.

They detected bipolar outflows and other signs of active, ongoing star formation. Eventually, the Snake nebula will dissolve and shine as a chain of several star clusters.

Pushy black holes stop elliptical galaxies from forming stars

Multi-wavelength view of the elliptical galaxy NGC 5044. Credit: Digitised Sky Survey /NASA Chandra /Southern Observatory for Astrophysical Research/Very Large Array. 

Contradicting past theories, cold gas has been found in abundance in some elliptical galaxies—showing that there must be some other explanation why these types of galaxies don't form new stars.

Astronomers believe that the jets from supermassive black holes in these galaxies' center must push around the gas and prevent stars from forming.

Researchers spotted the gas for the first time using old data from the recently retired Herschel space observatory, which was able to peer well into the infrared—where it spotted carbon ions and oxygen atoms.

This find stands against the previous belief that these galaxies were "red and dead", referring to their physical appearance and the fact that they form no new stars.

"We looked at eight giant elliptical galaxies that nobody had looked at with Herschel before and we were delighted to find that, contrary to previous belief, six out of eight abound with cold gas", stated Norbert Werner, a researcher at Stanford University in California who led the study.

"These galaxies are red, but with the giant black holes pumping in their hearts, they are definitely not dead," added Werner.

Previously, scientists thought that the galaxies got rid of their cold gas or had used it all up during a burst of earlier star formation.

With cold gas found in the majority of the sample, researchers then used other observatories to try to find warmer gas up to tens of millions of Kelvin (or Fahrenheit or Celsius).

NGC 1399, an elliptical galaxy about 65 million light years from Earth. Credit: NASA, Chandra

X-ray information from NASA's Chandra X-ray Observatory revealed that there is hot gas cooling in six of the eight galaxies, but not in the remaining two of the sample.

"This is consistent with theoretical expectations: once cooled, the hot gas would become the warm and cold gas that are observed at longer wavelengths.

However, in these galaxies the cooling process somehow stopped, and the cold gas failed to condense and form stars," the European Space Agency stated.

"While the six galaxies with plenty of cold gas harbour moderately active black holes at their centres," ESA added, "the other two show a marked difference."

"In the two galaxies without cold gas, the central black holes are accreting matter at frenzied pace, as confirmed by radio observations showing powerful jets of highly energetic particles that stem from their cores."

More information: N. Werner, J. B. R. Oonk, M. Sun, P. E. J. Nulsen, S. W. Allen, R. E. A. Canning, A. Simionescu, A. Hoffer, T. Connor, M. Donahue, A. C. Edge, A. C. Fabian, A. von der Linden, C. S. Reynolds, and M. Ruszkowski. "The origin of cold gas in giant elliptical galaxies and its role in fuelling radio-mode AGN feedback." MNRAS first published online February 24, 2014 DOI: 10.1093/mnras/stu006

MMS Satellites to study fundamental phenomenon of magnetic reconnection

Diagram of MMS spacecraft with communication components identified. 

Credit: NASA

First thing every morning, the engineering team for NASA's Magnetospheric Multiscale mission (MMS) gathers for a 10-minute meeting.

A white board sits at the front of the room with the day's assignments, who will wrap tape around the wires, which instruments need to be installed where, which observatory needs to undergo its next test.

This is the nerve center for the MMS engineers and technicians at NASA's Goddard Space Flight Center in Greenbelt, Md.

Goddard is tasked with an unprecedented feat for the center: building four identical observatories simultaneously.

The four spacecraft will launch together on a single rocket and then maneuver out into a pyramid configuration to orbit Earth.

Mechanical Engineers completed installation of the Solar Array panels for Observatory #4. 

There are eight panels per spacecraft, one enclosing each of the eight bays of the octagonal structure. 

When in orbit, the solar arrays will provide power to the Spacecraft during sunlight phases, while the battery (mounted inside the spacecraft deck) provides power during the 4 hour eclipses.

On its journey, MMS will observe a little-understood, but universal phenomenon called magnetic reconnection, responsible for dramatic re-shaping of the magnetic environment near Earth, often sending intense amounts of energy and fast-moving particles off in a new direction.

Not only is this a fundamental physical process that occurs throughout the universe, it is also one of the drivers of space weather events at Earth.

To truly understand the process, requires four identical spacecraft to track how such reconnection events move across and through any given space.

Building four spacecraft at once has many advantages. It saves on time and mission cost. However, such a massive undertaking requires meticulous logistical planning.

"This is the first time NASA has ever built four satellites simultaneously like this," said Craig Tooley, project manager for MMS at Goddard.

"It feels like we're planning a giant game of musical chairs to produce multiple copies of a spacecraft.

One instrument deck might be 2/3 finished, while another one is 1/3 finished, and the same people will have to test a nearly complete deck one day, and install large components on another one another day."

One of the earliest important feats for this group of engineers and technicians came during the design phase. Each spacecraft must carry, in addition to the navigational and power instruments, 25 scientific instruments.

These had to be carefully laid out so that each instrument had a full range of view and so that the eight booms sticking out from the spacecraft would not interfere with any other instrument's line of sight or electromagnetic systems.

NASA MAVEN: How magnetic crustal fields affect planets - Video

Radiation environments on Earth and Mars. Credit: NASA JPL

If you are ever lost on the surface of Mars, don't count on a compass to help you get home.

On Mars, compasses don't work.

They don't work because there is not one magnetic field on Mars, rather there are dozens.

These small fields are powerful, concentrated in the crust, and scattered over the surface of the planet.

In their absence, compass needles would lie still; in their presence, they spin, pointing first at one bar magnet, then another.

How well these crustal fields protect the planet is a mystery, and one that may be solved soon by the MAVEN satellite, which is on its way to Mars right now.

What we do know is that if a compass ever worked well on Mars, it was over 3.5 billion years ago.

Before that time, Mars had a molten core, whose contents constantly churned upward towards the surface.

This process of convection permitted cooling of the interior, as well as active volcanism in the highlands and plains. Volcanoes brought iron to the surface, giving Mars its signature colour.

Iron in the core also moved electrons, which created a planetary dynamo: a device that converts mechanical energy into electric energy.

Electric fields generate magnetic fields. Large magnetic fields can provide protection from solar wind for any planet as long its interior maintains a steadfast supply of molten metal.

Large magnetic fields also decay unless maintained. After the first billion years or so, the Martian interior cooled to the point where convection halted. When the iron ceased to flow, the dynamo died. Volcanism declined.

The last iron deposits from the interior left their marks as pockets of magnetism, called crustal anomalies, largely sequestered in the southern hemisphere.

"Mars is on the interesting borderline of the magnetized and the unmagnetized objects," said Janet Luhmann, MAVEN's deputy principal investigator.

"We think that the weak magnetic field has been in place since it was about a billion years old."

We first learned about Mars' strange magnetic fields from the way they interacted with the solar wind.

In 1965 Mariner 4, one of America's first interplanetary probes, passed within 8,000 kilometers (4,971 miles) of Mars' surface.

At that distance, it failed to detect any magnetic field. By contrast, Earth's planet-wide field can be sensed by magnetometers within 60,000 kilometers (37,282 miles).

What Mariner did note was that the solar wind was being bent around the planet, widely in some places.

Position of magnetometers on the MAVEN spacecraft. Credit: NASAexplorer

In terms of solar storms, MAVEN will arrive on the downslope of a solar cycle, during the optimum window for observing one of the most powerful forces affecting atmospheric escape: coronal mass ejections.

"More CMEs (and larger CMEs) occur during the declining phase of the solar cycle, rather than at maximum," said Frank Eparvier, science lead on the Extreme Ultraviolet (EUV) Sensors attached to LPW.

"MAVEN will be at Mars during the declining phase of the current solar cycle, so we will actually be there at the right time to see CME impacts."

ESA Gaia: Largest Space Camera is ready to map a billion stars

Now whizzing through space, 1.5 million km from Earth. 

Credit: ESA-CNES-Arianespace / Optique Vidéo du CSG - G. Barbaste

After its successful launch in December, European Space Agency's (ESA) Gaia has now taken up its position in space and is ready to survey the skies.

With the help of two onboard telescopes focused onto the largest ever space camera, Gaia is estimated to catalogue nearly one billion stars in its 5-year mission.

Like Hipparcos before it, ESA's Gaia will map stars in the Milky Way. It will do this by measuring the brightest billion objects and determine their three-dimensional distribution and velocities.

It also has the ability to measure the temperature, mass, and chemical composition of these billion objects.

Gaia will be able to discern objects up to 400,000 times dimmer than those visible to the naked eye.

The positional accuracy of its measurements are akin to measuring the width of a human hair at a distance of 500 km.

The process will involve scanning each part of the sky an average of 70 times over its five-year mission lifetime.

This means scanning the entire sky twice every 63 days, once through each of the two telescopes, making it a powerful tool for spotting time-evolving phenomena such as binary systems, supernovae, and exoplanets.

Compared to ESA's Hipparcos Space Telescope, ESA's Gaia will be able to measure 500 times the number of stars, extending to objects 1000 times dimmer than the dimmest that Hipparcos could catalogue.

Test image from Gaia: Slightly shaky to start with, but it’ll get there. Credit: ESA/DPAC/Airbus DS

The technology that makes this possible is the largest camera ever launched into space – 940 million pixels.

That is why a lot of effort before launch was on figuring out exactly how to get the huge amount of data Gaia will produce back down to Earth.

When a picture is taken a number of charged-coupled devices (CCDs), the stuff most digital camera sensors are made off, are dedicated to spotting objects before they fall onto the main focal plane.

This allows the instrument to track the objects as they pass and only retain small regions around the object, reducing the file-size needed to be sent to Earth.

In five years it will send only 100 TB of data (1 TB is 1000 GB).

Once the data arrives to Earth, there is a system in place to analyse the data and distribute alerts to ground-based observatories if anything quickly evolving and potentially interesting is spotted, such as supernovae.

The catalogue produced by Gaia is expected to contribute to many areas of astrophysics;

  • multiply our database of exotic objects such as' 
    • exoplanets, 
    • white and brown dwarfs, and 
    • supernovae many-fold, contribute to more precise measurements of General Relativity, 
  • help to constrain the measurements of the presence and location of dark matter, and 
  • give us more accurate information about our galactic neighbourhood and its evolution.

SpaceX Falcon 9 Rocket Adds Landing Legs

A look at the landing legs SpaceX is mounting on its Falcon 9 rocket for the company's next cargo mission to the International Space Station, which is slated to launch on March 16, 2014.

Credit: Elon Musk /SpaceX

Putting landing legs on the Falcon 9 rocket, which is slated to blast off on March 16, marks another step in SpaceX's quest to develop a fully reusable launch system but current plans don't call for the Falcon 9 to actually touch down on the legs after next month's liftoff, said SpaceX founder and CEO Elon Musk.

Elon Musk
"Mounting landing legs (~60 ft span) to Falcon 9 for next month's Space Station servicing flight," Musk said Sunday (Feb. 23) via Twitter, where he posted a photo of the rocket.

"However, F9 will continue to land in the ocean until we prove precision control from hypersonic thru subsonic regimes."

SpaceX holds a $1.6 billion contract to make 12 robotic supply runs to the space station for NASA using Dragon and the Falcon 9.

The company has already completed two of these flights successfully; the March 16 flight will initiate contracted mission number three.

But the company's ambitions extend far beyond low-Earth orbit. Musk has said that he established SpaceX primarily to help humanity become a multiplanet species, and he hopes the company plays a prominent role in getting a Mars colony up and running.

One key to making such big dreams a reality is developing a fully and rapidly reusable launch system, which Musk has said could lower the cost of spaceflight by a factor of 100.

Toward that end, SpaceX has been testing a reusable rocket prototype called Grasshopper, which has a made a series of higher and more complicated flights over the past year and a half.

NASA News from Planet-Hunting Kepler Space Telescope

NASA scientists will hold a public teleconference today to reveal the latest planet discoveries by the space agency's prolific Kepler Space Telescope and you can follow the major exoplanet news live online here.

The NASA Kepler mission teleconference will begin at 1 p.m. EST (1800 GMT) and will be webcast live via NASA.

Huge Peanut-Shaped Asteroid Buzzes Earth in NASA - Video

A large asteroid shaped like a cosmic peanut zipped safely by Earth this month, and a new NASA video retells the entire space rock encounter as it happened using impressive radar images.

Scientists using NASA's Deep Space Network Goldstone antenna in California tracked the near-Earth asteroid 2006 DP14 using radar imaging as the space rock passed within 2.6 million miles (4.2 million kilometers) of our planet on Feb. 12.

The new radar images show that 2006 DP14 is about 1,300 feet long (400 meters) and 660 feet wide (200 m).

NASA video of asteroid 2006 DP14's Earth flyby with the Goldstone radar images is shown above.

The asteroid is known as a "contact binary" because the two halves of its peanut shape seem to be touching and moving through space together.

2006 DP14 made its closest approach to Earth on Feb. 10 when it traveled about 1.5 million miles (2.4 million km) from the planet's surface, NASA officials said.

Scientists then observed the asteroid on Feb. 12 from 12:03 a.m. EST to 2:27 a.m. EST (0503 GMT to 0727 GMT).

"Radar is a powerful technique for studying an asteroid's size, shape, rotation state, surface features and surface roughness, and for improving the calculation of asteroid orbits," NASA representatives wrote in a statement.

"Radar measurements of asteroid distances and velocities often enable computation of asteroid orbits much further into the future than if radar observations weren't available."

Earlier studies have shown that about 10 percent of near-Earth asteroids larger than 650 feet (200 m) have contact binary shapes, NASA officials said.

Comets and asteroids are considered near-Earth objects (NEOs) of they fly within about 28 million miles (45 million km) of Earth's orbital distance, NASA officials have said.

Tuesday, February 25, 2014

NASA SDO images: Significant solar flare - X-class

An X-class solar flare erupted on the left side of the sun on the evening of Feb. 24, 2014. 

This composite image, captured by NASA's Solar Dynamics Observatory (SDO) satellite at 7:59 p.m. EST, shows the sun in X-ray light with wavelengths of both 131 and 171 angstroms. 

Credit: NASA /Solar Dynamics Observatory

The sun emitted a significant solar flare, peaking at 7:49 p.m. EST on Feb. 24, 2014.

NASA's Solar Dynamics Observatory (SDO), which keeps a constant watch on the sun, captured images of the event.

Solar flares are powerful bursts of radiation, appearing as giant flashes of light in the SDO images.

Harmful radiation from a flare cannot pass through Earth's atmosphere to physically affect humans on the ground, however, when intense enough, they can disturb the atmosphere in the layer where GPS and communications signals travel.

To see how this event may impact Earth, please visit NOAA's Space Weather Prediction Center, the U.S. government's official source for space weather forecasts, alerts, watches and warnings.

These SDO images from 7:25 p.m. EST on Feb. 24, 2014, show the first moments of an X-class flare in different wavelengths of light -- seen as the bright spot that appears on the left limb of the sun. 

Hot solar material can be seen hovering above the active region in the sun's atmosphere, the corona. Image 

Credit: NASA/SDO

This flare is classified as an X4.9-class flare. X-class denotes the most intense flares, while the number provides more information about its strength. An X2 is twice as intense as an X1, an X3 is three times as intense, etc.

Child's heart printed in 3D to aid complex surgery

Louisville Kentucky cardiothoracic surgeon Erle Austin has performed successful heart repair surgery on a 14 month old infant named Roland Lian Cung Bawi, heart surgery on such a young patient is not unheard of, of course, what's new is that Austin was able to map out his surgical approach using a nearly exact model of the patients heart, it had been printed on a 3D printer.

Erle Austin
Young Roland had been born with four congenital heart defects—doctors had known since before he was born that his heart had problems.

Fixing them all would prove to be a challenge. When it came time to plan the surgery, Austin consulted with other surgeons and found each of them had different ideas on the best way to fix the heart.

The ideal approach would involve the least amount of cutting and suturing—but that can be hard to plan using only conventional scanning techniques.

Looking for more precision, Austin turned to the engineering school at the University of Louisville, they'd been researching different kinds of 3D printing technology.

Researchers at the University worked with radiologists at Kosair Children's Hospital to create a means for converting data from a CT scan of Roland's heart to data that could be used with a 3D printer.

The two seemed a perfect match as CT scanning uses the same basic idea as 3D printing, it takes pictures of slices and puts them together on a computer screen to form a whole, and 3D printing is achieved by laying down one layer or "slice" of material at a time.

The 3D printing team used a MakerBot Replicator 2X, to print the heart (in three pieces) at twice its normal size, they also used a flexible type of plastic filament known as "Ninja Flex" instead of ABS.

Ninja Flex allowed the surgeon to bend the finished heart in ways that resembled a real human heart.

Printing the heart took approximately 20 hours at a cost of roughly $600.

Austin told local news reporters that the printed heart let him plan the surgery in ways he'd never experienced before, it allowed for a single surgery (this past February 10) and greatly reduced cutting and suturing, which ultimately led to a much quicker recovery for Roland, who by all accounts is now doing just fine.

Keck Observatory's NIRSPEC: Water vapour detected in the atmosphere of a hot Jupiter

Simulated data showing the method used for detecting water vapor features detected around the hot Jupiter tau Boo b. 

In this example, the planetary signal has been increased in strength relative by several orders of magnitude relative to the actual signal. 

The dotted lines show the blue- and red-shifts of the planetary and stellar lines in the data, respectively, due to the orbital motion of two bodies in the system. 

Credit: Alexandra Lockwood (CalTech), Background Image David Aguilar (CFA).

California Institute of Technology (Caltech) astronomers using data gathered at the W. M. Keck Observatory have developed a new technique for planetary scientists that could provide insight into how many water planets like Earth exist within our universe.

The results have been published on February 24th by Astrophysical Letters.

Alexandra Lockwood
Scientists have detected water vapour on other planets in the past, but these detections could only take place under very specific circumstances, according to graduate student Alexandra Lockwood, the first author of the study.

"When a planet transits, or passes in orbit, in front of its host star, we can use information from this event to detect water vapour and other atmospheric compounds."

"Alternatively, if the planet is sufficiently far away from its host star, we can also learn about a planet's atmosphere by imaging it."

However, a significant portion of the population of extrasolar planets does not fit either of these criteria and there wasn't really a way to find information about the atmospheres of these planets.

Geoffrey Blake
Looking to resolve this problem, Lockwood and her advisor Geoffrey Blake, Caltech professor of cosmochemistry, planetary sciences and chemistry, were inspired by the recent detection of carbon monoxide in the extrasolar planet, 'Tau Boo b' and they wondered if they could detect water in a similar manner.

The method used to detect carbon monoxide utilized the radial velocity (RV) technique, a technique commonly used in the visible region of the spectrum, to which our eyes are sensitive, for discovering non-transiting exoplanets.

Using the Doppler effect, RV detection traditionally determines the motion of a star due to the gravitational pull of a companion planet; the star moves opposite that of the orbital motion of the planet, and stellar features shift in wavelength. A large planet or a planet closer to its host star provides a larger shift.

An artistic impression of extrasolar planet, 'Tau Boo b

The team used the carbon monoxide study as a guide to expand the RV technique into the infrared to determine the orbit of extrasolar planet, 'Tau Boo b' around its star, and added further analysis of the light shifts via spectroscopy, an analysis of the light's spectrum.

Since every molecule emits a different wavelength of light, this unique light signature allows the researchers to analyze molecules that comprise the planet's atmosphere.

Using data of extrasolar planet, 'Tau Boo b' collected with the Near Infrared Echelle Spectrograph (NIRSPEC) instrument at the W. M. Keck Observatory in Hawai'i, the researchers were able to compare the molecular signature of water to the light spectrum emitted by the planet, confirming that the atmosphere did indeed include water vapour.

"The readout we get from Keck Observatory's NIRSPEC is like listening to an orchestra performance; you hear all of the music together, but if you listen carefully, you can pick out a trumpet or a violin or a cello, and you know that those instruments are present," Lockwood said.

"The instrument allows you to pick out different pieces; like this wavelength of light means that there is sodium, or this one means that there's water."

More information: "Near-IR Direct Detection of Water Vapour in Tau Boo b." Alexandra C. Lockwood, John A. Johnson, Chad F. Bender, John S. Carr, Travis Barman, Alexander J.W. Richert, Geoffrey A. Blake. arXiv:1402.0846 [astro-ph.EP].

NASA Terra Aqua MODIS: UK scientists reveal Amazon rainforest satellite imaging problem - Video

US Scientists have been puzzled by the apparent ‘greening up’ of the Amazon forest during its annual dry season.

However, Swansea University scientists, in research carried out in conjunction with NASA, have found that the Amazon is not as green in the dry season as researchers previously thought, because a trick of the light skews the satellite images.

The research is published in the latest issue of the scientific journal Nature; doi:10.1038/nature13006

This natural-colour satellite image shows the importance of correcting for sun-sensor geometry. 

On the left side, sunlight is backscattered by the Amazon rainforest, creating the appearance of brighter green leaves in some areas. 

To the right, sunglint makes the dark waters of the Amazon River and surrounding flooded wetlands appear silver or white compared to the darker forest. 

 Credit: NASA's Earth Observatory

The finding of the research yeam will help scientists develop a more accurate picture of changes in the Amazon, which is more important now than ever, given the enormous role the Amazon plays in regulating carbon dioxide, and influencing climate change.

NASA's Terra and Aqua satellites make daily observations over the huge expanse of Amazon forests.

The research team were investigating why previous satellite images seemed to show that the forests became greener during the dry season each year from June to October.

More greenery indicates productive, thriving vegetation, which would not be expected at a time of limited rainfall.

The new research shows that:
  • The apparent greening of the Amazon in the dry season is an illusion. The forest does not become greener at all.
  • It just looks that way due to a combination of shadowing within the forest canopy and the way that satellite sensors observe the Amazon during the dry season, which can create false “hot spots” in images.

Dr Jackie Rosette
‌Swansea researchers, working with NASA, developed a mathematical model which predicts how a forest will be seen from space, and how leaf area can be measured.

One of the Swansea team, Dr Jackie Rosette, spent 2 years at Goddard Space Flight Center, working closely with NASA colleagues.

Blue colours represent areas in Amazon forests where sensors and models can overestimate the green-up of vegetation; white represents areas that lack forest cover. 

The map is based on a model that extends the sun-sensor correction to all pixels in the southern Amazon. 

Credit: Doug Morton and NASA's Earth Observatory

Professor Peter North from the Department of Geography at Swansea University, one of the authors of the research paper, said:

"The Amazon is so vast that it’s only from space that we can properly observe it, so it’s very important that the satellite data gives us as accurate a picture as possible.

Our model has helped to identify the flaws in the previous interpretation. As a result, we can be much more confident that what we are seeing is a real pattern across the Amazon, not a trick of the light.

Having an accurate picture of the Amazon is essential if we are to understand its key role in shaping the climate."

Aboard the NASA satellites are sensors called MODIS (Moderate Resolution Imaging Spectroradiometer) which measure the amount of infrared light reflected from the Amazon.

Scientists use the ratio of red and near-infrared light as a measure of vegetation.

Doug Morton, NASA’s Goddard Space Flight Center said.

"We think we have uncovered the mechanism for the appearance of seasonal greening of Amazon forests – shadowing within the canopy that changes the amount of near-infrared light observed by MODIS"

The research implies that the previous hypothesis of increased productivity during dry seasons is likely to be false, and Amazon productivity may be more limited by water availability than sunlight.

This is critical for predicting the response of the Amazon to future climate change.

Monday, February 24, 2014

NASA DAWN Image: The large asteroid Vesta

The large asteroid Vesta appears multihued in this image, which uses the filters on the Dawn spacecraft to greatly enhance the subtle color differences on the surface. 

Each is probably due to different chemical compositions of the surface material. Up close, Vesta would look pretty much grey to the eye; see the text below for an explanation. 


Painted Stones video: Asteroids observed by the Sloan Digital Sky Survey

Alex Parker is an astronomer at UC Berkeley, where he researches minor planets—asteroids, Kuiper Belt Objects (giant iceballs orbiting past Neptune), and more.

He took the asteroids in the solar system observed by the Sloan Digital Sky Survey (over 100,000 of them) and created an animation showing their orbits, their relative sizes, and even their colors in the survey. 

The resulting video, “Painted Stones”, has been called 'simply wondrous.'

ESA Rosetta Image: One of Rosetta’s 14m solar wings over Mars Mawrth Vallis region

On 25 February 2007 at 02:15 GMT, ESA Rosetta passed just 250 km from the surface of Mars. 

Rosetta’s Philae lander took this image 4 minutes before closest approach, at a distance of 1000 km. 

It captures one of Rosetta’s 14 m-long solar wings, set against the northern hemisphere of Mars, where details in the Mawrth Vallis region can be seen.

Mawrth Vallis region of Mars is of particular interest to scientists because it contains minerals formed in the presence of water – a discovery made by ESA’s Mars Express.

This image was originally published in 2007 and was taken in black-and-white.

Mawrth Vallis region of Mars
Representative colour was added to the surface of Mars and, in this version, these colours have been slightly enhanced, along with some brightening of details in the solar wing.

On Sunday 2 March, ESA Rosetta celebrates ten years since launch.

The flyby at Mars was one of four planetary gravity assists (the other three were at Earth) needed to boost the spacecraft onto the correct trajectory to meet up with its target, comet 67P/Churyumov–Gerasimenko, in August 2014.

ESA Rosetta will become the first space mission to rendezvous with a comet, the first to attempt a landing, and the first to follow a comet as it swings around the Sun.

Space 'Harpoons' Could Snatch Samples of Asteroids and Moons

Artist's concept of a tethered "penetrator" heading toward a celestial body to take a sample. 

Credit: Chad Truitt, University of Washington

Why bother landing softly on an alien world to collect samples if you can just snag material with a harpoon from afar?

Using a set of long-lined, hard-hitting harpoons would allow a mission to grab large samples from multiple locations on an asteroid or moon — and to get them from beneath the surface, where some of the most interesting material lies, say researchers developing the idea.

Robert Winglee
"This technology will be able for the first time to pull samples of the order of a few kilograms from depths of a few meters, which could greatly enhance our knowledge of solar system objects and the resources therein," Robert Winglee of the University of Washington and his colleagues wrote in a NASA report detailing their project.

"Moreover, it offers the opportunity to take multiple samples (from either multiple objects or from multiple areas of a few objects) at little extra cost so that it will provide much greater flexibility and greatly enhance the science return for any given mission," they added.

The team's concept currently calls for a sample-return spacecraft to carry six lightweight, rocket-shaped "penetrators," which would be swung down at the target object(s) from orbit or during a flyby using a miles-long space tether.

The penetrators would hit at high speed — up to 2,240 mph (3,605 km/h, or 1 km/sec) or so — and go deep beneath the surface.

During the impact, they would collect several kilograms of material, which would be reeled back to the parent probe by the tether for eventual return to Earth.

The six-shooter approach enables the collection of multiple samples — an enticing prospect for scientists, Winglee said.

ESA Sentinel-1 unfolds its large solar wings and radar antenna

Sentinel-1 radar vision. Credit: ESA/ATG medialab

When Sentinel-1 is placed in orbit around Earth in a few weeks, it has to perform a complicated dance routine to unfold its large solar wings and radar antenna.

Engineers have recently been making sure the moves are well rehearsed.

Sentinel-1 is the first in a family of satellites built specifically to provide a stream of timely data for Europe's ambitious Copernicus environmental monitoring programme.

It carries an advanced radar instrument to image Earth's surface through cloud and rain, regardless of whether it is day or night.

Delivering vital information for numerous operational services, from monitoring ice in the polar oceans to tracking land subsidence, Sentinel-1 is set to play a key role in the largest civil Earth-observation programme ever conceived.

Moreover, this new mission is the only European satellite specifically designed for fast response to emergencies such floods and earthquakes.

About seven years in the making, this new satellite will soon be launched from Europe's Spaceport in French Guiana.

Sentinel-1 will be shipped to the launch site next week, but has spent the last couple of months at Thales Alenia Space in Cannes, France, being put through a last set of stringent tests.

This included suspending the satellite from a structure to simulate weightlessness and carefully unfolding the two 10 m-long solar wings and 12 m-long radar.

During launch, the solar wings and radar are folded up for protection and to fit into the Soyuz rocket fairing.

After the satellite is released into space, the solar wings and radar deploy together, but in a specific sequence that takes around 10 hours to complete.

The sequence is unique, choreographed to ensure that both deploy in the safest possible way.

The sequence also allows power from the wings to be available as soon as possible so that the satellite is independent.

The tests have shown that Sentinel-1 can handle this tricky sequence of events and passed with flying colours.

ESA's Sentinel-1 Project Manager, Ramón Torres, said, "The deployment test of the satellite's radar and solar array is a major achievement, especially since there were some very demanding requirements.

Sentinel-1A satellite during radio frequency tests. 

Credit: ESA–S. Corvaja, 2014

Spanish MODIS Astronomers observe record-breaking lunar impact in Mare Nubium

An image of the flash resulting from the impact of a large meteorite on the lunar surface on 11 September 2013, obtained with the ESO MIDAS observatory

Credit: J. Madiedo / MIDAS

A meteorite with the mass of a small car crashed into the Moon last September, according to Spanish astronomers.

The impact, the biggest seen to date, produced a bright flash and would have been easy to spot from the Earth.

The scientists publish their description of the event in the journal Monthly Notices of the Royal Astronomical Society.

The Moon lacks the atmosphere that prevents small rocks from space from reaching the surface of the Earth.

The result is very visible – vast numbers of craters large and small cover the whole of our nearest neighbour and record 4.5 billion years of collisions that span the history of the Solar system.

Although there is almost no chance of a very large object striking the Moon or planets, collisions with smaller objects are very common even today.

The odds of seeing one of these by chance are pretty poor, so scientists have set up networks of telescopes that can detect them automatically.

Jose M. Madiedo
On 11 September 2013, Prof Jose M. Madiedo was operating two telescopes in the south of Spain that were searching for these impact events.

At 2007 GMT he witnessed an unusually long and bright flash in Mare Nubium, an ancient lava-filled basin with a darker appearance than its surroundings.

The flash was the result of a rock crashing into the lunar surface and was briefly almost as bright as the familiar Pole Star, meaning that anyone on Earth who was lucky enough to be looking at the Moon at that moment would have been able to see it.

In the video recording made by Prof Madiedo, an afterglow remained visible for a further eight seconds.

The October event is the longest and brightest confirmed impact flash ever observed on the Moon. Prof Madiedo recalls how impressed he was: "At that moment I realised that I had seen a very rare and extraordinary event."

The Spanish telescopes are part of the Moon Impacts Detection and Analysis System (MIDAS) system that monitors the lunar surface.

Jose L. Ortiz
This project is being undertaken by Prof Jose Maria Madiedo, from the University of Huelva (UHU), and by Dr Jose L. Ortiz, from the Institute of Astrophysics of Andalusia (IAA-CSIC) and continues a pioneering program that detected sporadic lunar impact flashes for the first time.

Since these impacts take place at huge speeds, the rocks become molten and are vapourised at the impact site instantaneously, and this produces a thermal glow that can be detected from our planet as short-duration flashes through telescopes.

Generally, these flashes last just a fraction of a second but the flash detected on 11 September was much more intense and longer than anything observed before.

More Information: “A large lunar impact blast on 2013 September 11”, José M. Madiedo, José L. Ortiz, Nicolás Morales and Jesús Cabrera-Caño, Monthly Notices of the Royal Astronomical Society, Oxford University Press, in press. A copy of the paper is available from

Greenland Aurora Borealis Dragon's head

A dragon's head appears on the horizon as the Northern Lights (Aurora Borealis) dance across the night sky making magical shapes . 

The mythical creature formed in swathes of green light as particles bombard the Earth's atmosphere above the Arctic. 

Picture: Juan Carlos Casado/Barcroft

ESA Neosat boosting Europe's telecommunications by satellite

ESA is forging ahead with the Neosat next-generation satcom platform, planning the first flights within five years. 

The goal is for European satellite builders to capture at least half of the world's satcom market in 2018-30 through innovation and efficiency, generating 25 billion pounds in sales.

The contract for Phase-B of Neosat was signed today by Magali Vaissiere, ESA's Director of Telecommunications and Integrated Applications, and Eric Beranger and Bertrand Maureau for prime contractors Airbus Defence and Space, and Thales Alenia Space, respectively.

Magali Vaissiere commented: "Neosat will foster the competitiveness of European satellite industry and strengthen Europe's position in the core satcom market for the next decade.

"This is a unique opportunity for Europe's suppliers, as 80% of European satellite platform equipment is procured from within ESA Member States. This will be worth 7 billion pounds to those suppliers."

Magali Vaissiere, ESA’s Director of Telecoms,
Eric Béranger (EADS) and Bertrand Maureau (Thales)
The contract signed today covers selection of the equipment suppliers for the Neosat product lines.

The two co-primes will run competitions between equipment suppliers for platform building blocks, based on an agreed single set of requirements.

The winners of these competitions will become part of the industrial consortium for developing the two platform lines, one led by aerospace super-corporation EADS (European Airbus Defense and Space), and the other by Thales Alenia Space.

The upcoming phase will include concurrent engineering activities to define the technical baseline of the new platforms and involve subcontractors in the UK, Sweden, Switzerland and Luxembourg.

Technologies to be investigated for the future platforms include orbit raising by electric propulsion, new thermal control concepts and next-generation battery cells.

The Neosat prime contractors have activities in France and in the UK, both countries being major contributors to Neosat.

The contract for Phase-B is expected to last around 13 months. The subsequent Phase-C/D will start in 2015 for the development and manufacture of the first two prototype flight platforms, launch in 2018-19 and in-orbit demonstration under a public-private partnership to be established with satellite operators.

Neosat is part of ESA's Advanced Research in Telecommunications Systems programme (ARTES), and aims at developing, qualifying and validating in orbit next-generation satellite platforms for the core satcom market.

A crucial objective for Neosat is to reduce the cost of a satellite in orbit by 30% compared with today's designs by the end of the decade.

Existing and new technologies will be used in innovative ways and to achieve economies of scale by creating a common supply chain for both satellite prime contractors.