NASA Hubble Team Finds Monster "El Gordo" Galaxy Cluster Bigger Than Thought

 NASA's Hubble Space Telescope has weighed the largest known galaxy cluster in the distant universe, catalogued as ACT-CL J0102-4915, and found it definitely lives up to its nickname -- El Gordo (Spanish for "the fat one").

By measuring how much the cluster's gravity warps images of galaxies in the distant background, a team of astronomers has calculated the cluster's mass to be as much as 3 million billion times the mass of our sun. Hubble data show the galaxy cluster, which is 9.7 billion light-years away from Earth, is roughly 43 percent more massive than earlier estimates.

The team used Hubble to measure how strongly the mass of the cluster warped space. Hubble's high resolution allowed measurements of so-called "weak lensing," where the cluster's immense gravity subtly distorts space like a funhouse mirror and warps images of background galaxies. The greater the warping, the more mass is locked up in the cluster.

"What I did is basically look at the shapes of the background galaxies that are farther away than the cluster itself," explained lead author James Jee of the University of California at Davis. "It's given us an even stronger probability that this is really an amazing system very early in the universe."

A fraction of this mass is locked up in several hundred galaxies that inhabit the cluster and a larger fraction is in hot gas that fills the entire volume of the cluster. The rest is tied up in dark matter, an invisible form of matter that makes up the bulk of the mass of the universe.

Though equally massive galaxy clusters are found in the nearby part of the universe, such as the Bullet cluster, nothing like this has ever been discovered to exist so far back in time, when the universe was roughly half its current estimated age of 13.8 billion years. The team suspects such monster galaxy clusters are rare in the early universe, based on current cosmological models.

The immense size of El Gordo was first reported in January 2012. Astronomers estimated its mass based on observations made by NASA's Chandra X-ray Observatory, and galaxy velocities measured by the European Southern Observatory's Very Large Telescope array in Paranal, Chile. They were able to put together estimates of the cluster's mass based on the motions of the galaxies moving inside the cluster and the temperatures of the hot gas between those galaxies.

The challenge was that El Gordo looked as if it might have been the result of a titanic collision between a pair of galaxy clusters -- an event researchers describe as two cosmic cannonballs hitting each other.

"We wondered what happens when you catch a cluster in the midst of a major merger and how the merger process influences both the X-ray gas and the motion of the galaxies," explained John Hughes of Rutgers University. "So, the bottom line is because of the complicated merger state, it left some questions about the reliability of the mass estimates we were making."

That is where the Hubble data came in, according to Felipe Menanteau of the University of Illinois at Urbana-Champaign.

"We were in dire need for an independent and more robust mass estimate given how extreme this cluster is and how rare its existence is in the current cosmological model. There was all this kinematic energy that was unaccounted for and could potentially suggest that we were actually underestimating the mass," Menanteau said. 

The expectation of "unaccounted energy" comes from the fact the merger of galaxy clusters is occurring tangentially to the observers' line-of-sight. This means they are potentially missing a good fraction of the kinetic energy of the merger because their spectroscopic measurements only track the radial speeds of the galaxies.

The team's next step with Hubble will be to compile an image of the cluster. Because El Gordo does not fit into Hubble's field of view, the team will capture images of sections of the galaxy cluster and piece them together into a mosaic.

Researchers say it is like observing a giant from the side.

"We can tell it's a pretty big El Gordo, but we don't know what kind of legs he has, so we need to have a larger field of view to get the complete picture of the giant," said Menanteau

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

Source : www.nasa.com

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NASA's Curiosity Mars Rover Views Striated Ground

Martian Landscape With Rock Rows and Mount Sharp

This landscape scene photographed by NASA's Curiosity Mars rover shows rows of rocks in the foreground and Mount Sharp on the horizon.  Curiosity's Navigation Camera (Navcam) took the component images for this mosaic during a pause in driving on the 548th Martian day, or sol, of the rover's work on Mars (Feb. 19, 2014).  The Sol 548 drive covered 328 feet (100 meters)

    A close-up look at some of the striations from the rover's Navigation Camera gains extra drama by including Mount Sharp in the background. The lower slopes of that layered mountain are the mission's long-term science destination.

   The foreground rocks are in an outcrop called "Junda," which the rover passed during a drive of 328 feet (100 meters) on Feb. 19.  It paused during the drive to take the component images of the scene, then finished the day's drive.  A location still ahead, called "Kimberley," where researchers plan to suspend driving for a period of science investigations, also features ground with striations.

   NASA's Mars Science Laboratory Project is using Curiosity to assess ancient habitable environments and major changes in Martian environmental conditions. JPL, a division of the California Institute of Technology in Pasadena, built the rover and manages the project for NASA's Science Mission Directorate in Washington.

Source : www.nasa.gov

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NASA's Kepler Discovers First Earth-Size Planet In The 'Habitable Zone' of Another Star

The artist's concept depicts Kepler-186f , the first validated Earth-size planet to orbit a distant star in the habitable zone.

     Using NASA's Kepler Space Telescope, astronomers have discovered the first Earth-size planet orbiting a star in the "habitable zone" -- the range of distance from a star where liquid water might pool on the surface of an orbiting planet. The discovery of Kepler-186f confirms that planets the size of Earth exist in the habitable zone of stars other than our sun.

While planets have previously been found in the habitable zone, they are all at least 40 percent larger in size than Earth and understanding their makeup is challenging. Kepler-186f is more reminiscent of Earth.

"The discovery of Kepler-186f is a significant step toward finding worlds like our planet Earth," said Paul Hertz, NASA's Astrophysics Division director at the agency's headquarters in Washington. "Future NASA missions, like the Transiting Exoplanet Survey Satellite and the James Webb Space Telescope, will discover the nearest rocky exoplanets and determine their composition and atmospheric conditions, continuing humankind's quest to find truly Earth-like worlds."

Although the size of Kepler-186f is known, its mass and composition are not. Previous research, however, suggests that a planet the size of Kepler-186f is likely to be rocky.

"We know of just one planet where life exists -- Earth. When we search for life outside our solar system we focus on finding planets with characteristics that mimic that of Earth," said Elisa Quintana, research scientist at the SETI Institute at NASA's Ames Research Center in Moffett Field, Calif., and lead author of the paper published today in the journal Science. "Finding a habitable zone planet comparable to Earth in size is a major step forward."

Kepler-186f resides in the Kepler-186 system, about 500 light-years from Earth in the constellation Cygnus. The system is also home to four companion planets, which orbit a star half the size and mass of our sun. The star is classified as an M dwarf, or red dwarf, a class of stars that makes up 70 percent of the stars in the Milky Way galaxy.

"M dwarfs are the most numerous stars," said Quintana. "The first signs of other life in the galaxy may well come from planets orbiting an M dwarf."

Kepler-186f orbits its star once every 130-days and receives one-third the energy from its star that Earth gets from the sun, placing it nearer the outer edge of the habitable zone. On the surface of Kepler-186f, the brightness of its star at high noon is only as bright as our sun appears to us about an hour before sunset.

"Being in the habitable zone does not mean we know this planet is habitable. The temperature on the planet is strongly dependent on what kind of atmosphere the planet has," said Thomas Barclay, research scientist at the Bay Area Environmental Research Institute at Ames, and co-author of the paper. "Kepler-186f can be thought of as an Earth-cousin rather than an Earth-twin. It has many properties that resemble Earth."

The four companion planets, Kepler-186b, Kepler-186c, Kepler-186d, and Kepler-186e, whiz around their sun every four, seven, 13, and 22 days, respectively, making them too hot for life as we know it. These four inner planets all measure less than 1.5 times the size of Earth.

The next steps in the search for distant life include looking for true Earth-twins -- Earth-size planets orbiting within the habitable zone of a sun-like star -- and measuring the their chemical compositions. The Kepler Space Telescope, which simultaneously and continuously measured the brightness of more than 150,000 stars, is NASA's first mission capable of detecting Earth-size planets around stars like our sun.

Ames is responsible for 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 & 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 Kepler science data. Kepler is NASA's 10th Discovery Mission and was funded by the agency's Science Mission Directorate.

The SETI Institute is a private, nonprofit organization dedicated to scientific research, education and public outreach.  The mission of the SETI Institute is to explore, understand and explain the origin, nature and prevalence of life in the universe.

The diagram compares the planets of our inner solar system to Kepler-186, a five-planet star system about 500 light-years from Earth in the constellation Cygnus. The five planets of Kepler-186 orbit an M dwarf, a star that is is half the size and mass of the sun.

 Source : www.nasa.com

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NASA Observes World Water Day

On March 22, NASA will observe World Water Day. While our home planet is about 71 percent water, only 3 percent of that is available as fresh water. And many people do not have access to safe and clean water sources. On a water planet like Earth, "following the water" is a massive undertaking but one that is essential to predicting the future of our climate and the availability of water resources around the globe.

NASA’s research yields many benefits, including improved environmental prediction, as well as natural hazard and climate change preparedness. And NASA technology developed to keep astronauts safe and healthy in space benefits people on the ground, through new ways to monitor water resources and purify water for safe use.

Water is a critical piece of life on the International Space Station. Almost all the water used and produced by the astronauts is recycled – the Environmental Control Life Support System recycles about 93 percent of the water it receives. And NASA is continuing to improve the way it uses and recycles water in order to prepare for future long duration space exploration missions to an asteroid and Mars.

That same technology is now being used in humanitarian efforts to provide clean water to people following natural disasters and in other areas of the world where safe drinking water is not available.

Here on Earth, global change will impact many aspects of society, including global water resources, food security, human health, natural hazards, ecodiversity, and international relations. NASA people and science are working to document and understand changes on our planet, predict their ramifications, and share that information with decision makers to better analyze, anticipate, and act to influence events that will affect us and future generations.

In 2014, for the first time in more than a decade, five NASA Earth Science missions will be launched into space in one year. Together with NASA's existing fleet of satellites, airborne missions, and researchers, these new missions will help answer some of the critical challenges facing our planet today and in the future: climate change, sea level rise, freshwater resources, and extreme weather events.

Source :  http://www.nasa.gov/content/nasa-observes-world-water-day/

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Herschel to Complete Its Mission Soon

This artist’s impression of Herschel is set against an image captured by the observatory, showing baby stars forming in the Rosette nebula. Image credit: ESA - C. Carreau 

The Herschel space observatory is expected to exhaust its supply of liquid helium coolant in the coming weeks, after spending more than three years studying the cool universe and surpassing the expectations of the international team of scientists involved.

Herschel is a European Space Agency (ESA) mission with important participation from NASA. The telescope was launched on May 14, 2009. With a main mirror 11.5 feet (3.5 meters) across, it is the largest, most powerful infrared telescope ever flown in space.

A pioneering mission, Herschel is the first to cover the entire wavelength range from far-infrared to submillimeter, making it possible to study previously invisible cool regions of gas and dust in the cosmos, and providing new insights into the origin and evolution of stars and galaxies.

To make such sensitive far-infrared observations, the detectors of the three science instruments -- two cameras/imaging spectrometers and a very high-resolution spectrometer -- must be cooled to a frigid minus 456 degrees Fahrenheit (minus 271 degrees Celsius), close to absolute zero. They sit on top of a tank filled with superfluid liquid helium, inside a giant thermos flask known as a cryostat.

The superfluid helium evaporates over time, gradually emptying the tank and determining Herschel's scientific life. At launch, the cryostat was filled to the brim with more than 606 gallons (2,300 liters) of liquid helium, weighing 739 pounds (335 kilograms), for 3.5 years of operations in space.

Herschel has made extraordinary discoveries across a wide range of topics, from starburst galaxies in the distant universe to newly forming planetary systems orbiting nearby young stars.

However, all good things must come to an end, and engineers believe that almost all of the liquid helium is now gone.

It is not possible to predict the exact day the helium will finally run out, but when it happens, confirmation will come when Herschel begins its next daily three-hour communication period with ground stations on Earth.

The science-observing program was carefully planned to take full advantage of the lifetime of the mission, with all of the highest-priority observations already completed.

"We have known from the beginning of the mission that Herschel's lifetime would be limited by the supply of liquid helium." said Paul Goldsmith, the NASA Herschel Project Scientist at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "So the whole team worked very hard to make the best use of every minute of observing time."

In addition, Herschel is performing numerous other interesting observations specifically chosen to exploit every last drop of helium.

"When observing comes to an end, we expect to have performed over 22,000 hours of science observations, 10 percent more than we had originally planned, so the mission has already exceeded expectations," said Leo Metcalfe, the Herschel Science Operations and Mission Manager at ESA's European Space Astronomy Centre in Madrid, Spain.

"We will finish observing soon, but Herschel data will enable a vast amount of exciting science to be done for many years to come," says Göran Pilbratt, ESA's Herschel Project Scientist at ESA's European Space Research and Technology Center in Noordwijk, the Netherlands.

"In fact, the peak of scientific productivity is still ahead of us, and the task now is to make the treasure trove of Herschel data as valuable as possible for now and for the future."

Herschel will continue communicating with its ground stations for some time after the helium is exhausted, allowing a range of technical tests. Finally, in early May, it will be propelled into its long-term stable parking orbit around the sun.

Herschel is a European Space Agency cornerstone mission, with science instruments provided by consortia of European institutes and with important participation by NASA. NASA's Herschel Project Office is based at NASA's Jet Propulsion Laboratory, Pasadena, Calif. JPL contributed mission-enabling technology for two of Herschel's three science instruments. The NASA Herschel Science Center, part of the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena, supports the United States astronomical community. Caltech manages JPL for NASA.

 Source : http://www.nasa.gov/mission_pages/herschel/news/herschel20130305.html

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NASA's Hubble Reveals Rogue Planetary Orbit For Fomalhaut B

This false-color composite image, taken with the Hubble Space Telescope, reveals the orbital motion of the planet Fomalhaut b. Based on these observations, astronomers calculated that the planet is in a 2,000-year-long, highly elliptical orbit. The planet will appear to cross a vast belt of debris around the star roughly 20 years from now. If the planet's orbit lies in the same plane with the belt, icy and rocky debris in the belt could crash into the planet's atmosphere and produce various phenomena. The black circle at the center of the image blocks out the light from the bright star, allowing reflected light from the belt and planet to be photographed. The Hubble images were taken with the Space Telescope Imaging Spectrograph in 2010 and 2012. Credit: NASA, ESA, and P. Kalas (University of California, Berkeley and SETI Institute)

Newly released NASA Hubble Space Telescope images of a vast debris disk encircling the nearby star Fomalhaut and a mysterious planet circling it may provide forensic evidence of a titanic planetary disruption in the system.

Astronomers are surprised to find the debris belt is wider than previously known, spanning a section of space from 14 to nearly 20 billion miles from the star. Even more surprisingly, the latest Hubble images have allowed a team of astronomers to calculate the planet follows an unusual elliptical orbit that carries it on a potentially destructive path through the vast dust ring.

The planet, called Fomalhaut b, swings as close to its star as 4.6 billion miles, and the outermost point of its orbit is 27 billion miles away from the star. The orbit was recalculated from the newest Hubble observation made last year.

"We are shocked. This is not what we expected," said Paul Kalas of the University of California at Berkeley and the SETI Institute in Mountain View, Calif.

The Fomalhaut team led by Kalas considers this circumstantial evidence there may be other planet-like bodies in the system that gravitationally disturbed Fomalhaut b to place it in such a highly eccentric orbit. The team presented its finding Tuesday at the 221st meeting of the American Astronomical Society in Long Beach, Calif.

Among several scenarios to explain Fomalhaut b's 2,000-year-long orbit is the hypothesis that an as yet undiscovered planet gravitationally ejected Fomalhaut b from a position closer to the star, and sent it flying in an orbit that extends beyond the dust belt.

"Hot Jupiters get tossed through scattering events, where one planet goes in and one gets thrown out," said co-investigator Mark Clampin of NASA's Goddard Space Flight Center in Greenbelt, Md. "This could be the planet that gets thrown out."

Hubble also found the dust and ice belt encircling the star Fomalhaut has an apparent gap slicing across the belt. This might have been carved by another undetected planet. Hubble's exquisite view of the dust belt shows irregularities that strongly motivate a search for other planets in the system.

If its orbit lies in the same plane with the dust belt, then Fomalhaut b will intersect the belt around 2032 on the outbound leg of its orbit. During the crossing, icy and rocky debris in the belt could crash into the planet's atmosphere and create the type of cosmic fireworks seen when Comet Shoemaker-Levy 9 crashed into Jupiter. Most of the fireworks from collisions will be seen in infrared light. However, if Fomalhaut b is not co-planar with the belt, the only thing to be seen will be a gradual dimming of Fomalhaut b as it travels farther from the star.

Kalas hypothesized that Fomalhaut b's extreme orbit is a major clue in explaining why the planet is unusually bright in visible light, but very dim in infrared light. It is possible the planet's optical brightness originates from a ring or shroud of dust around the planet, which reflects starlight. The dust would be rapidly produced by satellites orbiting the planet, which would suffer extreme erosion by impacts and gravitational stirring when Fomalhaut b enters into the planetary system after a millennium of deep freeze beyond the main belt. An analogy can be found by looking at Saturn, which has a tenuous, but very large dust ring produced when meteoroids hit the outer moon Phoebe.

The team has also considered a different scenario where a hypothetical second dwarf planet suffered a catastrophic collision with Fomalhaut b. The collision scenario would explain why the star Fomalhaut has a narrow outer belt linked to an extreme planet. But in this case the belt is young, less than 10,000 years old, and it is difficult to produce energetic collisions far from the star in such young systems.

Fomalhaut is a special system because it looks like scientists may have a snapshot of what our solar system was doing 4 billion years ago. The planetary architecture is being redrawn, the comet belts are evolving, and planets may be gaining and losing their moons. Astronomers will continue monitoring Fomalhaut b for decades to come because they may have a chance to observe a planet entering an icy debris belt that is like the Kuiper Belt at the fringe of our own solar system.

Source : http://www.nasa.gov/mission_pages/hubble/science/rogue-fomalhaut.html

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