NASA Telescopes Help Identify Most Distant Galaxy Cluster

NASA - SPITZER Space Telescope logo.

Jan. 12, 2011

Astronomers have uncovered a burgeoning galactic metropolis, the most distant known in the early universe. This ancient collection of galaxies presumably grew into a modern galaxy cluster similar to the massive ones seen today.

The developing cluster, named COSMOS-AzTEC3, was discovered and characterized by multi-wavelength telescopes, including NASA's Spitzer, Chandra and Hubble space telescopes, and the ground-based W.M. Keck Observatory and Japan's Subaru Telescope.

Astronomers have discovered a massive cluster of young galaxies forming in the distant universe. Image credit: Subaru / NASA / JPL-Caltech.

"This exciting discovery showcases the exceptional science made possible through collaboration among NASA projects and our international partners," said Jon Morse, NASA's Astrophysics Division director at NASA Headquarters in Washington.

Scientists refer to this growing lump of galaxies as a proto-cluster. COSMOS-AzTEC3 is the most distant massive proto-cluster known, and also one of the youngest, because it is being seen when the universe itself was young. The cluster is roughly 12.6 billion light-years away from Earth. Our universe is estimated to be 13.7 billion years old. Previously, more mature versions of these clusters had been spotted at 10 billion light-years away.

The astronomers also found that this cluster is buzzing with extreme bursts of star formation and one enormous feeding black hole.

"We think the starbursts and black holes are the seeds of the cluster," said Peter Capak of NASA's Spitzer Science Center at the California Institute of Technology in Pasadena. "These seeds will eventually grow into a giant, central galaxy that will dominate the cluster -- a trait found in modern-day galaxy clusters." Capak is first author of a paper appearing in the Jan. 13 issue of the journal Nature.

Most galaxies in our universe are bound together into clusters that dot the cosmic landscape like urban sprawls, usually centered around one old, monstrous galaxy containing a massive black hole. Astronomers thought that primitive versions of these clusters, still forming and clumping together, should exist in the early universe. But locating one proved difficult -- until now.

Capak and his colleagues first used the Chandra X-ray Observatory and the United Kingdom's James Clerk Maxwell Telescope on Mauna Kea, Hawaii, to search for the black holes and bursts of star formation needed to form the massive galaxies at the centers of modern galaxy cities. The astronomers then used Hubble and the Subaru telescopes to estimate the distances to these objects, and look for higher densities of galaxies around them. Finally, the Keck telescope was used to confirm that these galaxies were at the same distance and part of the same galactic sprawl.

Once the scientists found this lumping of galaxies, they measured the combined mass with the help of Spitzer. At this distance the optical light from stars is shifted, or stretched, to infrared wavelengths that can only be observed in outer space by Spitzer. The lump sum of the mass turned out to be a minimum of 400 billion suns -- enough to indicate that the astronomers had indeed uncovered a massive proto-cluster.

Spitzer (Artist's view)

The Spitzer observations also helped confirm a massive galaxy at the center of the cluster was forming stars at an impressive rate. Chandra X-ray observations were used to find and characterize the whopping black hole with a mass of more than 30 million suns. Massive black holes are common in present-day galaxy clusters, but this is the first time a feeding black hole of this heft has been linked to a cluster that is so young.

Finally, the Institut de Radioastronomie Millimétrique's interferometer telescope in France and 30-meter telescope in Spain, along with the National Radio Astronomy Observatory's Very Large Array telescope in New Mexico, measured the amount of gas, or fuel for future star formation, in the cluster. The results indicate the cluster will keep growing into a modern city of galaxies.

"It really did take a village of telescopes to nail this cluster," said Capak. "Observations across the electromagnetic spectrum, from X-ray to millimeter wavelengths, were all critical in providing a comprehensive view of the cluster's many facets."

COSMOS-AzTEC3, located in the constellation Sextans, is named after the region where it was found, called COSMOS after the Cosmic Evolution Survey. AzTEC is the name of the camera used on the James Clerk Maxwell Telescope -- this camera is now on its way to the Large Millimeter Telescope located in Mexico's Puebla state.

For more information about NASA's Spitzer, Chandra and Hubble space telescopes, visit:

http://www.nasa.gov/spitzer

http://www.nasa.gov/chandra

http://www.nasa.gov/hubble 

More information about Spitzer is at: http://spitzer.caltech.edu/

Images, Text, Credits: NASA / JPL-Caltech / Subaru.

Greetings, Orbiter.ch

Mars500 - Of emergencies and Christmas trees - an exciting end to 2010

ESA - ROSCOSMOS Mars500 Mission patch.

12 January 2011

In the 10th Mars500 Mission Diary, Romain writes about end-of-year excitements in the crew’s spacecraft mockup on their virtual journey to Mars. With almost half the mission completed, the crew is now counting the days to their ‘arrival’ in orbit around the red planet, on 1 February.

Romain smiling happily with a cardboard Christmas tree and socks full of presents

During the last few weeks we experienced two major events inside our Mars500 modules. First, an off-nominal situation left us for 20 hours without water, electricity and ventilation during the first two days of December. The second event is merrier: Christmas! Let me share with you how we went through these both.

On 1 December I had a busy morning. With Sukhrob we are responsible for two experiments, which need to be performed in parallel and involve many devices. When we started to work with this experiment six months ago, we spent about three hours each time on the two subject persons, but over time we have developed some routines increasing our efficiency. Now we can finish it within one or one and a half hours.

One example of our time-saving tricks deals with the electrodes for Sukhrob’s experiment. Instead of bumping into each other while he sticks his electrodes to one of the subjects and I put in place a blood-pressure measurement device, we share half of the electrodes and each of us takes one side of the body of our subject. Everything went well for our both subjects, Diego and Wang Yue.

After that I went to my room where I began to study Russian. I was still in my room when, around at 13:00 hours, suddenly the power went down and everything stopped around us except the security lights and the computers with batteries.

Dark and silent…

Kitchen table during the power outage

The crew gathered in the kitchen to share information and define the best action plan. While the others were retrieving personal lights, Alexey and I checked all the power units of the modules. For each of them all the interrupters were OK. At that moment we received a message from ground control telling us that the main transformer of the building surrounding our modules was on fire.

We didn’t know how long it would take for the engineers’ team to solve the problem. So, to save some power on the emergency batteries and to avoid any new issues, we unplugged all the electric devices and we even removed the bulb of some security lamps which weren’t needed. In the end only two lights remained: one in the kitchen and one near the bathroom.

To understand our situation, you have to imagine an ‘end of the world’ scene. We were only 6 crewmembers lost in black modules with a thick silence around us. The friendly humming of the ventilation disappeared at the same time as the electricity. We couldn’t even get more than 2 litres from the tap because the pressure given by the pumps inside the water system had fallen too. Our reaction was to stick together close to the only place which still had a light: the kitchen.

As all our systems inside our facility were functioning nominally, all we could do was wait for additional information from the outside. Around 14:00, when we began to get hungry, we also realized that we didn’t have any microwave or kettle working, and so we decided to eat what was available: cereals, cakes and juice.

We received a new update on the repair of the transformer from the ground control around 16:00.

They told us that they could by-pass the system to restart one of our big fridges. It was a relief because the temperature of our four fridges was approaching 0°C. It would have been a disaster to lose half of our supplies! As soon as we got this information we went to the storage module to save our frozen food.

Three teams quickly formed to do three main tasks: to empty two small fridges near the greenhouse, to empty the non-functioning big fridge, and to store everything in the remaining big fridge. Making sure that everything fit inside the cold room was a challenge but we managed to do it.

Along with the working fridge all our low-voltage electricity became available in the storage module. So we settled inside the gym around 17:00. We stayed calm during the whole off-nominal situation, but still we received occasional audio messages from ground control asking us to be patient.

Before dinner time we brought the small table from the living room and we prepared some food. Bread, butter, cheese and cakes filled our stomach for this peculiar evening. One by one we left the gym to get some rest in our black and noiseless rooms. Only Alexey and Alexander were still awake when I went to bed after midnight.

Back to nominal

The next morning I woke up at 06:00. The air around me was still and the temperature was higher than usual. I couldn’t hear anything in the modules, so I went back to sleep. At 07:45 I opened my eyes again and I saw a light appearing. I automatically stood up and went to check what was happening.

Alexey - who took the night shift –told me that the light was back, but not the 220V current, nor the ventilation and nor the water. However he added that the electricity was back in the medical module. I immediately went there with a full kettle to have some warm water. We could enjoy a good breakfast with hot tea and coffee: what a delight!

One hour later a familiar sound reached our ears: after 20h of silence the ventilation was on again! One by one all our systems came back to life: first ventilation, then electricity and finally water. We spent the rest of the day performing our scheduled tasks and also checking all our systems for any abnormal reaction to the power cut. At 16:00 on 2 December we received a video message from the ground control telling us that all the systems were nominal. This also when we learned that the event lasting 27 hours was a drill! Even if it took us some time to digest this last bit of information we enjoyed this unexpected event. It was a new situation breaking our monotonous days!

Christmas celebration

A couple of weeks later with Diego we began to organise our Christmas. In France, in Italy and in Colombia this celebration has a strong meaning and we generally spend the 24 and 25 December with our families. Being several millions kilometres away from Earth we had to find a way to let the spirit of Christmas enter our modules. Another difficulty was to explain it to the other crew members because Christmas day is just a normal day for them. Day after day they saw our excitement growing with curiosity.

Decoration is essential for a good Christmas party so we drew up a ‘to-do’ list to be sure that nothing was forgotten.

The first item was the trickiest because we didn’t bring any pine tree with us. After a brainstorming session we gathered enough ideas to build our Mars500 Christmas tree. I spent with Alexey one afternoon around some cardboard boxes, cutting and painting three branches that we assembled together. Once our Christmas tree was able to stand upright we worked on its decoration:

# One garland (that I brought with me) was rolled around it, but it wasn’t enough.
# Some small inflatable balloons - which looked like balls – were hung on the tree, but it wasn’t enough.
# I remembered how to build small figurines with cardboard and we put six of them on the branches, but it wasn’t enough.
# The electrodes of one experiment were used to add some lights all over the branches… but it was still not enough!

In the end Sukhrob was the one to understand what was missing. He disappeared for ten minutes and came back with a big star to put on top of our creation. The Christmas tree was complete! The first line of our ‘to-do’ list was completed.

Romain shows how a christmas tree can be made of cardboard boxes

Our next step was to decorate our walls and for this occasion Diego used his Photoshop skills to draw several images. Once they were finished and printed, we stuck them all around the place along with some green and red balloons. With that we finished a new line of our ‘to-do’ list.

For a good Christmas ambiance we needed a fireplace. This kind of device is quite difficult to find in a spaceship. However Diego had the solution to our problem. He found a picture of a fireplace and printed a big poster of it. Once it was stuck on the living room we could hang six socks above it: one for each crewmember.

Compared to all the trouble that we had to go through until now, the last item was almost too easy! I had with me a cardboard nativity scene and we only used a bit of glue to assemble it.

Romain's cardboard nativity scene

Our preparation was now over and we were proud to take some pictures near the fireplace.

On 25 December we opened our presents just before lunch. It was a real pleasure to discover all the gifts falling, little by little, from the socks: metallic bottles from Russia, small glasses from Colombia, cards from China and chocolates from France.

Sharing this Christmas day with my five international crewmates after more than 200 days in isolation will definitely be one of the important days of our trip to Mars.

I have one last thing to add: Happy New Year from the Mars500 crew!

Related links:

Mars500 quick facts: http://www.esa.int/SPECIALS/Mars500/SEMGX9U889G_0.html

Mars500 crew: http://www.esa.int/SPECIALS/Mars500/SEMO4BU889G_0.html

Images, Video, Text, Credits: ESA / ROSCOSMOS / Mars500 Crew.

Cheers, Orbiter.ch

Planck’s new view of the cosmic theatre

ESA - PLANCK Mission patch.

11 January 2011

The first scientific results from ESA’s Planck mission were released at a press briefing today in Paris. The findings focus on the coldest objects in the Universe, from within our Galaxy to the distant reaches of space.

If William Shakespeare were an astronomer living today, he might write that “All the Universe is a stage, and all the galaxies merely players.” Planck is bringing us new views of both the stage and players, revealing the drama of the evolution of our Universe.

Planck's Early Release Compact Source Catalogue

Following the publication by ESA of the first full-sky Planck image in July last year, today sees the release of the first scientific results from the mission.

These results are being presented by the Planck Collaboration at a major scientific conference in Paris this week, based on 25 papers submitted to the journal Astronomy & Astrophysics.

The basis of many of these results is the Planck mission’s ‘Early Release Compact Source Catalogue’, the equivalent of a cast list.

Planck investigates the cosmic infrared background

Drawn from Planck’s continuing survey of the entire sky at millimetre and submillimetre wavelengths, the catalogue contains thousands of very cold, individual sources which the scientific community is now free to explore.

“This is a great moment for Planck. Until now, everything has been about collecting data and showing off their potential. Now, at last, we can begin the discoveries,” says Jan Tauber, ESA Project Scientist for Planck.

We can think of the Universe as a stage on which the great cosmic drama plays out over three acts.

Visible-light telescopes see little more than the final act: the tapestry of galaxies around us. But by making measurements at wavelengths between the infrared and radio, Planck is able to work back in time and show us the preceding two acts. The results released today contain important new information about the middle act, when the galaxies were being assembled.

Planck shows galaxy formation taking place

Planck has found evidence for an otherwise invisible population of galaxies shrouded in dust billions of years in the past, which formed stars at rates some 10–1000 times higher than we see in our own Galaxy today. Measurements of this population had never been made at these wavelengths before. “This is a first step, we are just learning how to work with these data and extract the most information,” says Jean-Loup Puget, CNRS-Université Paris Sud, Orsay, France.

Eventually, Planck will show us the best views yet of the Universe’s first act: the formation of the first large-scale structures in the Universe, where the galaxies were later born. These structures are traced by the cosmic microwave background radiation, released just 380 000 years after the Big Bang, as the Universe was cooling.

However, in order to see it properly, contaminating emission from a whole host of foreground sources must first be removed. These include the individual objects contained in the Early Release Compact Source Catalogue, as well as various sources of diffuse emission.

Planck zeros in on anomalous emission in Rho Ophiucus

Today, an important step towards removing this contamination was also announced. The ‘anomalous microwave emission’ is a diffuse glow most strongly associated with the dense, dusty regions of our Galaxy, but its origin has been a puzzle for decades.

However, data collected across Planck’s unprecedented wide wavelength range confirm the theory that it is coming from dust grains set spinning at several tens of billion times a second by collisions with either fast-moving atoms or packets of ultraviolet light.

This new understanding helps to remove this local microwave ‘fog’ from the Planck data with greater precision, leaving the cosmic microwave background untouched.

“This is a great result made possible by the exceptional quality of the Planck data,” says Clive Dickinson, University of Manchester, UK.

Among the many other results presented today, Planck has shown new details of yet other actors on the cosmic stage: distant clusters of galaxies. These show up in the Planck data as compact silhouettes against the cosmic microwave background.

Newly detected galaxy supercluster PLCK G214.6+37.0

The Planck Collaboration has identified 189 so far, including 20 previously unknown clusters that are being confirmed by ESA’s XMM-Newton X-ray observatory.

By surveying the whole sky, Planck stands the best chance of finding the most massive examples of these clusters. They are rare and their number is a sensitive probe of the kind of Universe we live in, how fast it is expanding, and how much matter it contains.

“These observations will be used as bricks to build our understanding of the Universe,” says Nabila Aghanim, CNRS-Université Paris Sud, Orsay, France.

“Today’s results are the tip of the scientific iceberg. Planck is exceeding expectations thanks to the dedication of everyone involved in the project,” says David Southwood, ESA Director of Science and Robotic Exploration.

“However, beyond those announced today, this catalogue contains the raw material for many more discoveries. Even then, we haven’t got to the real treasure yet, the cosmic microwave background itself.”

Planck continues to survey the Universe. Its next data release is scheduled for January 2013 and will reveal the cosmic microwave background in unprecedented detail, the opening act of the cosmic drama, a picture of the beginning of everything.

Notes for editors: http://www.esa.int/esaCP/SEME4F3SNIG_index_0.html

Related links:

Planck on Chromoscope: http://www.chromoscope.net/

Images, Videos, Text, Credits: ESA / Planck Collaboration / XMM-Newton image: ESA.

Greetings, Orbiter.ch

NASA'S Fermi Catches Thunderstorms Hurling Antimatter Into Space

NASA - Fermi Gamma-ray Space Telescope logo.

Jan. 10, 2011

Scientists using NASA's Fermi Gamma-ray Space Telescope have detected beams of antimatter produced above thunderstorms on Earth, a phenomenon never seen before.

Scientists think the antimatter particles were formed in a terrestrial gamma-ray flash (TGF), a brief burst produced inside thunderstorms and shown to be associated with lightning. It is estimated that about 500 TGFs occur daily worldwide, but most go undetected.

"These signals are the first direct evidence that thunderstorms make antimatter particle beams," said Michael Briggs, a member of Fermi's Gamma-ray Burst Monitor (GBM) team at the University of Alabama in Huntsville (UAH). He presented the findings Monday, during a news briefing at the American Astronomical Society meeting in Seattle.

Video above: NASA's Fermi Gamma-ray Space Telescope has detected beams of antimatter launched by thunderstorms. Acting like enormous particle accelerators, the storms can emit gamma-ray flashes, called TGFs, and high-energy electrons and positrons. Scientists now think that most TGFs produce particle beams and antimatter. Credit: NASA's Goddard Space Flight Center.

Fermi is designed to monitor gamma rays, the highest energy form of light. When antimatter striking Fermi collides with a particle of normal matter, both particles immediately are annihilated and transformed into gamma rays. The GBM has detected gamma rays with energies of 511,000 electron volts, a signal indicating an electron has met its antimatter counterpart, a positron.

Although Fermi's GBM is designed to observe high-energy events in the universe, it's also providing valuable insights into this strange phenomenon. The GBM constantly monitors the entire celestial sky above and the Earth below. The GBM team has identified 130 TGFs since Fermi's launch in 2008.

"In orbit for less than three years, the Fermi mission has proven to be an amazing tool to probe the universe. Now we learn that it can discover mysteries much, much closer to home," said Ilana Harrus, Fermi program scientist at NASA Headquarters in Washington.

Video above: Fermi’s Gamma-ray Burst Monitor detected 130 TGFs from August 2008 to the end of 2010. Thanks to instrument tweaks, the team has been able to improve the detection rate to several TGFs per week. (No audio.) Credit: NASA.

The spacecraft was located immediately above a thunderstorm for most of the observed TGFs, but in four cases, storms were far from Fermi. In addition, lightning-generated radio signals detected by a global monitoring network indicated the only lightning at the time was hundreds or more miles away. During one TGF, which occurred on Dec. 14, 2009, Fermi was located over Egypt. But the active storm was in Zambia, some 2,800 miles to the south. The distant storm was below Fermi's horizon, so any gamma rays it produced could not have been detected.

"Even though Fermi couldn't see the storm, the spacecraft nevertheless was magnetically connected to it," said Joseph Dwyer at the Florida Institute of Technology in Melbourne, Fla. "The TGF produced high-speed electrons and positrons, which then rode up Earth's magnetic field to strike the spacecraft."

The beam continued past Fermi, reached a location, known as a mirror point, where its motion was reversed, and then hit the spacecraft a second time just 23 milliseconds later. Each time, positrons in the beam collided with electrons in the spacecraft. The particles annihilated each other, emitting gamma rays detected by Fermi's GBM.

Image above: On Dec. 14, 2009, while NASA's Fermi flew over Egypt, the spacecraft intercepted a particle beam from a terrestrial gamma-ray flash (TGF) that occurred over its horizon. Fermi's Gamma-ray Burst Monitor detected the signal of positrons annihilating on the spacecraft -- not once, but twice. After passing Fermi, some of the particles reflected off of a magnetic "mirror" point and returned. Credit: NASA's Goddard Space Flight Center.

Scientists long have suspected TGFs arise from the strong electric fields near the tops of thunderstorms. Under the right conditions, they say, the field becomes strong enough that it drives an upward avalanche of electrons. Reaching speeds nearly as fast as light, the high-energy electrons give off gamma rays when they're deflected by air molecules. Normally, these gamma rays are detected as a TGF.

But the cascading electrons produce so many gamma rays that they blast electrons and positrons clear out of the atmosphere. This happens when the gamma-ray energy transforms into a pair of particles: an electron and a positron. It's these particles that reach Fermi's orbit.

Video above: A TGF produces gamma rays (magenta) as well as high-energy electrons (yellow) and positrons (green). This simulation tracks a TGF and its particle beams from their origin altitude of 9.3 miles (15 km) to 373 miles (600 km), beyond Fermi's orbit. Credit: Joe Dwyer/Florida Inst. of Technology

The detection of positrons shows many high-energy particles are being ejected from the atmosphere. In fact, scientists now think that all TGFs emit electron/positron beams. A paper on the findings has been accepted for publication in Geophysical Research Letters.

"The Fermi results put us a step closer to understanding how TGFs work," said Steven Cummer at Duke University. "We still have to figure out what is special about these storms and the precise role lightning plays in the process."

This images above illustrates how thunderstorms launch particle beams into space. Credit: NASA's Goddard Space Flight Center/J. Dwyer, Florida Inst. of Technology.

NASA's Fermi Gamma-ray Space Telescope is an astrophysics and particle physics partnership. It is managed by NASA's Goddard Space Flight Center in Greenbelt, Md. It was developed in collaboration with the U.S. Department of Energy, with important contributions from academic institutions and partners in France, Germany, Italy, Japan, Sweden and the United States.

The GBM Instrument Operations Center is located at the National Space Science Technology Center in Huntsville, Ala. The team includes a collaboration of scientists from UAH, NASA's Marshall Space Flight Center in Huntsville, the Max Planck Institute for Extraterrestrial Physics in Germany and other institutions.

For more Fermi information, images and animations, visit: http://www.nasa.gov/fermi 

Related Links:

Download related video and visuals from NASA Goddard's Scientific Visualization Studio: http://svs.gsfc.nasa.gov/vis/a010000/a010700/a010706/index.html

Images, Videos, Text, Credits: NASA / Goddard Space Flight Center.

Best regards, Orbiter.ch

Hubble Zooms in on a Space Oddity

ESA - Hubble Space Telescope logo.

10 January 2011

A strange, glowing green cloud of gas that has mystified astronomers since its discovery in 2007 has been studied by Hubble. The cloud of gas is lit up by the bright light of a nearby quasar, and shows signs of ongoing star formation.

Hubble snaps image of space oddity

One of the strangest space objects ever seen is being scrutinised by the penetrating vision of the NASA/ESA Hubble Space Telescope. A mysterious, glowing green blob of gas is floating in space near a spiral galaxy. Hubble uncovered delicate filaments of gas and a pocket of young star clusters in the giant object, which is the size of the Milky Way.

The Hubble revelations are the latest finds in an ongoing probe of Hanny’s Voorwerp (Hanny’s Object in Dutch). It is named after Hanny van Arkel, the Dutch schoolteacher who discovered the ghostly structure in 2007 while participating in the online Galaxy Zoo project. Galaxy Zoo enlists the public to help classify more than a million galaxies catalogued in the Sloan Digital Sky Survey. The project has expanded to include Galaxy Zoo: Hubble, in which the public is asked to assess tens of thousands of galaxies in deep imagery from the Hubble Space Telescope.

Infrared image of area surrounding Hanny’s Voorwerp

In the sharpest view yet of Hanny’s Voorwerp, Hubble’s Wide Field Camera 3 and Advanced Camera for Surveys have uncovered star birth in a region of the green object that faces the spiral galaxy IC 2497, located about 650 million light-years from Earth. Radio observations have shown an outflow of gas arising from the galaxy’s core. The new Hubble images reveal that the galaxy’s gas is interacting with a small region of Hanny’s Voorwerp, which is collapsing and forming stars. The youngest stars are a couple of million years old.

The greenish Voorwerp is visible because a searchlight beam of light from the galaxy’s core has illuminated it. This beam came from a quasar — a bright, energetic object that is powered by a black hole. The quasar is thought to have turned off less than 200 000 years ago.

Astronomer Bill Keel of the University of Alabama in Tuscaloosa, USA, leader of the Hubble study, is presenting his results on this object today at the American Astronomical Society meeting in Seattle, USA. Read more about his preliminary findings in the NASA news release linked below.
Notes

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

Image credit: NASA, ESA, William Keel (University of Alabama, Tuscaloosa), and the Galaxy Zoo team

Links:

    * NASA news release: http://hubblesite.org/newscenter/archive/releases/2011/01

    * Images of Hubble: http://www.spacetelescope.org/images/archive/category/spacecraft/

    * Hanny van Arkel’s blog: http://www.hannysvoorwerp.com/

    * Galaxy Zoo: http://www.galaxyzoo.com/

Images, Text, Credits: NASA / ESA / William Keel (University of Alabama, Tuscaloosa), and the Galaxy Zoo team / Hubble Heritage Team (STScI/AURA).

Best regards, Orbiter.ch

NASA's Kepler Mission Discovers Its First Rocky Planet

NASA - Kepler Mission logo labeled.

Jan. 10, 2011

NASA's Kepler mission confirmed the discovery of its first rocky planet, named Kepler-10b. Measuring 1.4 times the size of Earth, it is the smallest planet ever discovered outside our solar system.

The discovery of this so-called exoplanet is based on more than eight months of data collected by the spacecraft from May 2009 to early January 2010.

"All of Kepler's best capabilities have converged to yield the first solid evidence of a rocky planet orbiting a star other than our sun," said Natalie Batalha, Kepler's deputy science team lead at NASA's Ames Research Center in Moffett Field, Calif., and primary author of a paper on the discovery accepted by the Astrophysical Journal. "The Kepler team made a commitment in 2010 about finding the telltale signatures of small planets in the data, and it's beginning to pay off."

Artist concept of Kepler 10b

Kepler's ultra-precise photometer measures the tiny decrease in a star's brightness that occurs when a planet crosses in front of it. The size of the planet can be derived from these periodic dips in brightness. The distance between the planet and the star is calculated by measuring the time between successive dips as the planet orbits the star.

Kepler is the first NASA mission capable of finding Earth-size planets in or near the habitable zone, the region in a planetary system where liquid water can exist on the planet's surface. However, since it orbits once every 0.84 days, Kepler-10b is more than 20 times closer to its star than Mercury is to our sun and not in the habitable zone.

Kepler-10 was the first star identified that could potentially harbor a small transiting planet, placing it at the top of the list for ground-based observations with the W.M. Keck Observatory 10-meter telescope in Hawaii.

Scientists waiting for a signal to confirm Kepler-10b as a planet were not disappointed. Keck was able to measure tiny changes in the star's spectrum, called Doppler shifts, caused by the telltale tug exerted by the orbiting planet on the star.

"The discovery of Kepler 10-b is a significant milestone in the search for planets similar to our own," said Douglas Hudgins, Kepler program scientist at NASA Headquarters in Washington. "Although this planet is not in the habitable zone, the exciting find showcases the kinds of discoveries made possible by the mission and the promise of many more to come," he said.

Knowledge of the planet is only as good as the knowledge of the star it orbits. Because Kepler-10 is one of the brighter stars being targeted by Kepler, scientists were able to detect high frequency variations in the star's brightness generated by stellar oscillations, or starquakes. This analysis allowed scientists to pin down Kepler-10b's properties.

There is a clear signal in the data arising from light waves that travel within the interior of the star. Kepler Asteroseismic Science Consortium scientists use the information to better understand the star, just as earthquakes are used to learn about Earth's interior structure. As a result of this analysis, Kepler-10 is one of the most well characterized planet-hosting stars in the universe.

Video above: NASA's Kepler mission confirmed the discovery of its first rocky planet, named Kepler-10b. Measuring 1.4 times the size of Earth, it is the smallest planet ever discovered outside our solar system. The discovery of this so-called exoplanet is based on more than eight months of data collected by the spacecraft from May 2009 to early January 2010. This video is narrated by Kepler Deputy Science Team Lead Natalie Batalha.

That's good news for the team studying Kepler-10b. Accurate stellar properties yield accurate planet properties. In the case of Kepler-10b, the picture that emerges is of a rocky planet with a mass 4.6 times that of Earth and with an average density of 8.8 grams per cubic centimeter -- similar to that of an iron dumbbell.

Ames manages Kepler's ground system development, mission operations and science data analysis. NASA's Jet Propulsion Laboratory in Pasadena, Calif., managed Kepler mission development.

Ball Aerospace and Technologies Corp. in Boulder, Colo., developed the Kepler flight system and supports mission operations with the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder. The Space Telescope Science Institute in Baltimore archives, hosts and distributes the Kepler science data.

Kepler is NASA's 10th Discovery Mission and is funded by NASA's Science Mission Directorate at the agency's headquarters. For more information about the Kepler mission, visit: http://www.nasa.gov/kepler

Images, Video, Text, Credit: NASA.

Cheers, Orbiter.ch

Hotspots in Fountains on the Sun's Surface Help Explain Coronal Heating Mystery

NASA - Solar Dynamics Observatory (SDO) patch.

Jan. 10, 2011

Among the many constantly moving, appearing, disappearing and generally explosive events in the sun's atmosphere, there exist giant plumes of gas -- as wide as a state and as long as Earth -- that zoom up from the sun's surface at 150,000 miles per hour. Known as spicules, these are one of several phenomena known to transfer energy and heat throughout the sun's magnetic atmosphere, or corona.

Thanks to NASA's Solar Dynamics Observatory (SDO) and the Japanese satellite Hinode, these spicules have recently been imaged and measured better than ever before, showing them to contain hotter gas than previously observed. Thus, they may perhaps play a key role in helping to heat the sun's corona to a staggering million degrees or more. (A number made more surprising since the sun's surface itself is only about 10,000 degrees Fahrenheit.)

Image above: Spicules on the sun, as observed by the Solar Dynamics Observatory. These bursts of gas jet off the surface of the sun at 150,000 miles per hour and contain gas that reaches temperatures over a million degrees. Credit: NASA Goddard / SDO / AIA.

Just what makes the corona so hot is a poorly understood aspect of the sun's complicated space weather system. That system can reach Earth, causing auroral lights and, if strong enough, disrupting Earth's communications and power systems. Understanding such phenomena, therefore, is an important step towards better protecting our satellites and power grids.

"The traditional view is that all heating happens higher up in the corona," says solar physicist Dean Pesnell, SDO's project scientist at NASA's Goddard Space Flight Center in Greenbelt, Md. "The suggestion in this paper is that cool gas is ejected from the sun's surface in spicules and gets heated on its way to the corona. This doesn't mean the old view has been completely overturned, but this is a strong suggestion that part of the spicule material gets heated to very high temperatures and provides some coronal heating."

Spicules were first named in the 1940s, but were hard to study in detail until recently, says Bart De Pontieu of Lockheed Martin's Solar and Astrophysics Laboratory, Palo Alto, Calif. whose work on this subject appears in the January 7, 2011 issue of Science magazine.

In visible light, spicules can be seen to send large masses of so-called plasma – the electromagnetic gas that surrounds the sun -- up through the lower solar atmosphere or photosphere. The amount of material sent up is stunning, some 100 times as much as streams away from the sun in the solar wind towards the edges of the solar system. But nobody knew if they contained hot gas.

Video above: The rapidly changing black-and-white pattern in the right portion of this video shows the insertion of hot plasma into coronal loops on the sun. This hot plasma originates as spicules at the root of the coronal structure. Spicules are giant plumes of gas -- as wide as a state and as long as Earth -- that zoom up from the sun's surface at 150,000 mph. Video Credit: NCAR / Scott McIntosh (No audio.)

"Heating of spicules to the necessary hot temperatures has never been observed, so their role in coronal heating had been dismissed as unlikely," says De Pontieu.

Now, De Pontieu's team -- which included researchers at Lockheed Martin, the High Altitude Observatory of the National Center for Atmospheric Research (NCAR) in Colorado and the University of Oslo, Norway -- was able to combine images from SDO and Hinode to produce a more complete picture of the gas inside these gigantic fountains.

Tracking the movement and temperature of spicules relies on successfully identifying the same phenomenon in all the images. One complication comes from the fact that different instruments "see" gas at different temperatures. Pictures from Hinode in the visible light range, for example, show only cool gas, while pictures that record UV light show gas that is up to several million degrees.

To show that the previously known cool gas in a spicule lies side by side to some very hot gas requires showing that the hot and cold gas in separate images are located in the same space. Each spacecraft offered specific advantages to help confirm that one was seeing the same event in multiple images.

First, Hinode: In 2009, scientists used observations from Hinode and telescopes on Earth to, for the first time, identify a spicule when looking at it head-on. (Imagine how tough it is, looking from over 90 million miles away, to determine that you're looking at a fountain when you only have a top-down view instead of a side view.) The top-down view of a spicule ensures an image with less extraneous solar material between the camera and the fountain, thus increasing confidence that any observations of hotter gas are indeed part of the spicule itself.

Image above: Artist's concept of the Solar Dynamics Observatory, which recently helped observe the intense heat in fountains on the sun's surface, called spicules. Credit: Conceptual Image Lab, NASA's Goddard Space Flight Center.

The second aid to tracking a single spicule is SDO's ability to capture an image of the sun every 12 seconds. "You can track things from one image to the next and know you're looking at the same thing in a different spot," says Pesnell. "If you had an image only every 12 minutes, then you couldn't be sure that what you're looking at is the same event, since you didn't watch its whole history."

Bringing these tools together, scientists could compare simultaneous images in SDO and Hinode to create a much more complete image of spicules. They found that much of the gas is heated to a hundred thousand degrees, while a small fraction of the gas is heated to millions of degrees. Time-lapsed images show that this hot material spews high up into the corona, with much of it falling back down towards the surface of the sun. However, the small fraction of the gas that is heated to millions of degrees does not immediately return to the surface."Given the large number of spicules on the Sun, and the amount of material in the spicules, if even some of that super hot plasma stays aloft it would make a fair contribution to coronal heating," says Scott McIntosh from NCAR, who is part of the research team.

Of course, De Pontieu cautions that this does not yet solve the coronal heating mystery. The main result, he says, is that they're challenging theorists to incorporate the possibility that some coronal heating occurs at lower heights in the solar atmosphere. His next step is to help figure out how much of a role spicules play by studying how spicules form, how they move so quickly, how they get heated to such high temperatures in a short time, and how much mass stays up in the corona.

Astrophysicist Jonathan Cirtain, who is the U.S. project scientist for Hinode at NASA's Marshall Space Flight Center, Huntsville, Ala. points out that incorporating such new information helps address an important question that reaches far beyond the sun. "This breakthrough in our understanding of the mechanisms which transfer energy from the solar photosphere to the corona addresses one of the most compelling questions in stellar astrophysics: How is the atmosphere of a star heated?" he says. "This is a fantastic discovery, and demonstrates the muscle of the NASA Heliophysics System Observatory, comprised of numerous instruments on multiple observatories."

Hinode is the second mission in NASA's Solar Terrestrial Probes program, the goal of which is to improve understanding of fundamental solar and space physics processes. The mission is led by the Japan Aerospace Exploration Agency (JAXA) and the National Astronomical Observatory of Japan (NAOJ). The collaborative mission includes the U.S., the United Kingdom, Norway and Europe. NASA Marshall manages Hinode U.S. science operations and oversaw development of the scientific instrumentation provided for the mission by NASA, academia and industry. The Lockheed Martin Advanced Technology Center is the lead U.S. investigator for the Solar Optical Telescope on Hinode.

SDO is the first mission in a NASA science program called Living With a Star, the goal of which is to develop the scientific understanding necessary to address those aspects of the sun-Earth system that directly affect our lives and society. NASA Goddard built, operates, and manages the SDO spacecraft for NASA's Science Mission Directorate in Washington.

Related Link:

Read the related press release: http://www.nasa.gov/centers/goddard/news/releases/2011/11-001.html

NASA's SDO website: http://www.nasa.gov/sdo

Images, Video, Text, Credits: NASA's Goddard Space Flight Center / Goddard / SDO / AIA / NCAR / Scott McIntosh / Conceptual Image Lab.

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