Space In The News: July 2013

Wednesday, July 31, 2013

NASA's Cassini Spacecraft Reveals Forces Controlling Saturn Moon Jets

News release: 2013-237 July 31, 2013

NASA's Cassini Spacecraft Reveals Forces Controlling Saturn Moon Jets

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.php?release=2013-237&cid=release_2013-237

PASADENA, Calif. -- The intensity of the jets of water ice and organic particles that shoot out from Saturn's moon Enceladus depends on the moon's proximity to the ringed planet, according to data obtained by NASA's Cassini spacecraft.

The finding adds to evidence that a liquid water reservoir or ocean lurks under the icy surface of the moon. This is the first clear observation the bright plume emanating from Enceladus' south pole varies predictably. The findings are detailed in a scientific paper in this week's edition of Nature.

"The jets of Enceladus apparently work like adjustable garden hose nozzles," said Matt Hedman, the paper's lead author and a Cassini team scientist based at Cornell University in Ithaca, N.Y. "The nozzles are almost closed when Enceladus is closer to Saturn and are most open when the moon is farthest away. We think this has to do with how Saturn squeezes and releases the moon with its gravity."

Cassini, which has been orbiting Saturn since 2004, discovered the jets that form the plume in 2005. The water ice and organic particles spray out from several narrow fissures nicknamed "tiger stripes."

"The way the jets react so responsively to changing stresses on Enceladus suggests they have their origins in a large body of liquid water," said Christophe Sotin, a co-author and Cassini team member at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Liquid water was key to the development of life on Earth, so these discoveries whet the appetite to know whether life exists everywhere water is present."

For years scientists hypothesized the intensity of the jets likely varied over time, but no one had been able to show they changed in a recognizable pattern. Hedman and colleagues were able to see the changes by examining infrared data of the plume as a whole, obtained by Cassini's visual and infrared mapping spectrometer (VIMS), and looking at data gathered over a long period of time.

The VIMS instrument, which enables the analysis of a wide range of data including the hydrocarbon composition of the surface of another Saturnian moon, Titan, and the seismological signs of Saturn's vibrations in its rings, collected more than 200 images of the Enceladus plume from 2005 to 2012.

These data show the plume was dimmest when the moon was at the closest point in its orbit to Saturn. The plume gradually brightened until Enceladus was at the most distant point, where it was three to four times brighter than the dimmest detection. This is comparable to moving from a dim hallway into a brightly lit office.

Adding the brightness data to previous models of how Saturn squeezes Enceladus, the scientists deduced the stronger gravitational squeeze near the planet reduces the opening of the tiger stripes and the amount of material spraying out. They think the relaxing of Saturn's gravity farther away from planet allows the tiger stripes to be more open and for the spray to escape in larger quantities.

"Cassini's time at Saturn has shown us how active and kaleidoscopic this planet, its rings and its moons are," said Linda Spilker, Cassini project scientist at JPL. "We've come a long way from the placid-looking Saturn that Galileo first spied through his telescope. We hope to learn more about the forces at work here as a microcosm for how our solar system formed."

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL, a division of the California Institute of Technology, Pasadena, manages the mission for NASA's Science Mission Directorate in Washington. The VIMS team is based at the University of Arizona in Tucson.

For more information about the Cassini mission, visit: http://www.nasa.gov/cassini and http://saturn.jpl.nasa.gov .

Jia-Rui C. Cook 818-354-0850
Jet Propulsion Laboratory, Pasadena, Calif.
jccook@jpl.nasa.gov

Dwayne Brown 202-358-1726
NASA Headquarters, Washington
dwayne.c.brown@nasa.gov

- end -

Remove yourself from this mailing.

Remove yourself from all mailings from NASA Jet Propulsion Laboratory.

Spitzer Discovers Young Stars with a 'Hula Hoop'

News feature: 2013-236 July 31, 2013

Spitzer Discovers Young Stars with a 'Hula Hoop'

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.php?release=2013-236&cid=release_2013-236

Astronomers using NASA's Spitzer Space Telescope have spotted a young stellar system that "blinks" every 93 days. Called YLW 16A, the system likely consists of three developing stars, two of which are surrounded by a disk of material left over from the star-formation process.

As the two inner stars whirl around each other, they periodically peek out from the disk that girds them like a hula hoop. The hoop itself appears to be misaligned from the central star pair, probably due to the disrupting gravitational presence of the third star orbiting at the periphery of the system. The whole system cycles through bright and faint phases, with the central stars playing a sort of cosmic peek-a-boo as the tilted disk twirls around them. It is believed that this disk should go on to spawn planets and the other celestial bodies that make up a solar system.

Spitzer observed infrared light from YLW 16A, emitted by the warmed gas and dust in the disk that still swathes the young stars. Other observations came from the ground-based 2MASS survey, as well as from the NACO instrument at the European Southern Observatory's Very Large Telescope in Chile.

YLW 16A is the fourth example of a star system known to blink in such a manner, and the second in the same star-forming region Rho Ophiuchus. The finding suggests that these systems might be more common than once thought. Blinking star systems with warped disks offer scientists a way to study how planets form in these environments. The planets can orbit one or both of the stars in the binary star system. The famous science fictional planet Tatooine in "Star Wars" orbits two stars, hence its double sunsets. Such worlds are referred to as circumbinary planets. Astronomers can record how light is absorbed by planet-forming disks during the bright and faint phases of blinking stellar systems, which in turn reveals information about the materials that comprise the disk.

"These blinking systems offer natural probes of the binary and circumbinary planet formation process," said Peter Plavchan, a scientist at the NASA Exoplanet Science Institute and Infrared Processing and Analysis Center at the California Institute of Technology, Pasadena, Calif., and lead author of a new paper accepted for publication in Astronomy & Astrophysics.

NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at Caltech. Data are archived at the Infrared Science Archive housed at the Infrared Processing and Analysis Center. Caltech manages JPL for NASA. For more information about Spitzer, visit http://spitzer.caltech.edu and http://www.nasa.gov/spitzer .

Written by Adam Hadhazy
Contact:
Whitney Clavin 818-354-4673
Jet Propulsion Laboratory, Pasadena, Calif.
whitney.clavin@jpl.nasa.gov

- end -

Remove yourself from this mailing.

Remove yourself from all mailings from NASA Jet Propulsion Laboratory.

ScienceDaily: Astronomy News

Planetary 'runaway greenhouse' more easily triggered, research shows

Posted: 30 Jul 2013 01:31 PM PDT

It might be easier than previously thought for a planet to overheat into the scorchingly uninhabitable "runaway greenhouse" stage, according to new research.

Station astronauts remotely control planetary rover from space

Posted: 30 Jul 2013 06:15 AM PDT

On June 17 and July 26, NASA tested the Surface Telerobotics exploration concept, in which an astronaut in an orbiting spacecraft remotely operates a robot on a planetary surface.

ScienceDaily: Extrasolar Planets News

Planetary 'runaway greenhouse' more easily triggered, research shows

Posted: 30 Jul 2013 01:31 PM PDT

It might be easier than previously thought for a planet to overheat into the scorchingly uninhabitable "runaway greenhouse" stage, according to new research.

Tuesday, July 30, 2013

ScienceDaily: Black Holes News

Capturing black hole spin could further understanding of galaxy growth

Posted: 29 Jul 2013 08:14 PM PDT

Astronomers have found a new way of measuring the spin in supermassive black holes, which could lead to better understanding about how they drive the growth of galaxies.

ScienceDaily: Extrasolar Planets News

NASA's Chandra sees eclipsing planet in X-rays for first time

Posted: 29 Jul 2013 01:16 PM PDT

For the first time since exoplanets, or planets around stars other than the sun, were discovered almost 20 years ago, X-ray observations have detected an exoplanet passing in front of its parent star. An advantageous alignment of a planet and its parent star in the system HD 189733, which is 63 light-years from Earth, enabled NASA's Chandra X-ray Observatory and the European Space Agency's XMM Newton Observatory to observe a dip in X-ray intensity as the planet transited the star.

Pulsating star sheds light on exoplanet

Posted: 29 Jul 2013 01:15 PM PDT

Astronomers have devised a way to measure the internal properties of stars —- a method that offers more accurate assessments of their orbiting planets.

ScienceDaily: Astronomy News

Capturing black hole spin could further understanding of galaxy growth
NASA's Chandra sees eclipsing planet in X-rays for first time
Pulsating star sheds light on exoplanet

Capturing black hole spin could further understanding of galaxy growth

Posted: 29 Jul 2013 08:14 PM PDT

Astronomers have found a new way of measuring the spin in supermassive black holes, which could lead to better understanding about how they drive the growth of galaxies.

NASA's Chandra sees eclipsing planet in X-rays for first time

Posted: 29 Jul 2013 01:16 PM PDT

Pulsating star sheds light on exoplanet

Posted: 29 Jul 2013 01:15 PM PDT

Astronomers have devised a way to measure the internal properties of stars —- a method that offers more accurate assessments of their orbiting planets.

ScienceDaily: Galaxies News

Capturing black hole spin could further understanding of galaxy growth

Posted: 29 Jul 2013 08:14 PM PDT

Astronomers have found a new way of measuring the spin in supermassive black holes, which could lead to better understanding about how they drive the growth of galaxies.

ScienceDaily: Stars News

NASA's Chandra sees eclipsing planet in X-rays for first time

Posted: 29 Jul 2013 01:16 PM PDT

Pulsating star sheds light on exoplanet

Posted: 29 Jul 2013 01:15 PM PDT

Astronomers have devised a way to measure the internal properties of stars —- a method that offers more accurate assessments of their orbiting planets.

ScienceDaily: Cosmic Rays News

Capturing black hole spin could further understanding of galaxy growth
NASA's Chandra sees eclipsing planet in X-rays for first time
Experimental quest to test Einstein's speed limit

Capturing black hole spin could further understanding of galaxy growth

Posted: 29 Jul 2013 08:14 PM PDT

Astronomers have found a new way of measuring the spin in supermassive black holes, which could lead to better understanding about how they drive the growth of galaxies.

NASA's Chandra sees eclipsing planet in X-rays for first time

Posted: 29 Jul 2013 01:16 PM PDT

Experimental quest to test Einstein's speed limit

Posted: 29 Jul 2013 08:19 AM PDT

Special relativity states that the speed of light is the same in all frames of reference and that nothing can exceed that limit. UC Berkeley physicists used a novel experimental system -- the unusual electron orbitals of dysprosium -- to test whether the maximum speed of electrons follows this rule. The answer is yes, to tighter limits than ever before. They plan another experiment a thousand times more sensitive, approaching the realm where theory may break down.

Saturday, July 27, 2013

ScienceDaily: Astronomy News

Hubble eyes a mysterious old spiral

Posted: 26 Jul 2013 10:58 AM PDT

A striking cosmic whirl is the center of galaxy NGC 524, as seen with the NASA/ESA Hubble Space Telescope. This galaxy is located in the constellation of Pisces, some 90 million light-years from Earth.

ScienceDaily: Stars News

Hubble eyes a mysterious old spiral

Posted: 26 Jul 2013 10:58 AM PDT

ScienceDaily: Galaxies News

Hubble eyes a mysterious old spiral

Posted: 26 Jul 2013 10:58 AM PDT

Friday, July 26, 2013

ScienceDaily: Stars News

Largest magnetic fields in the universe
Scientists discover surprising importance of 'I Love Q' for understanding neutron stars
Image of sun-approaching comet ISON

Largest magnetic fields in the universe

Posted: 26 Jul 2013 01:34 AM PDT

Numerical simulations show for the first time the occurrence of an instability in the interior of neutron stars that can lead to gigantic magnetic fields, possibly triggering one of the most dramatic explosions observed in the Universe.

Scientists discover surprising importance of 'I Love Q' for understanding neutron stars

Posted: 25 Jul 2013 11:17 AM PDT

Astrophysicists have discovered why scientists can learn a tremendous amount about neutron stars and quark stars without knowing the details of their internal structure.

Image of sun-approaching comet ISON

Posted: 25 Jul 2013 11:15 AM PDT

In this Hubble composite image taken in April 2013, the sun-approaching Comet ISON floats against a seemingly infinite backdrop of numerous galaxies and a handful of foreground stars.

ScienceDaily: Galaxies News

Image of sun-approaching comet ISON

Posted: 25 Jul 2013 11:15 AM PDT

In this Hubble composite image taken in April 2013, the sun-approaching Comet ISON floats against a seemingly infinite backdrop of numerous galaxies and a handful of foreground stars.

ScienceDaily: Astronomy News

Largest magnetic fields in the universe
Centaurs: NASA's WISE finds mysterious centaurs may be comets
NASA's IRIS telescope offers first glimpse of sun's mysterious atmosphere
Image of sun-approaching comet ISON

Largest magnetic fields in the universe

Posted: 26 Jul 2013 01:34 AM PDT

Centaurs: NASA's WISE finds mysterious centaurs may be comets

Posted: 25 Jul 2013 12:15 PM PDT

The true identity of centaurs, the small celestial bodies orbiting the sun between Jupiter and Neptune, is one of the enduring mysteries of astrophysics. Are they asteroids or comets? A new study of observations from NASA's Wide-field Infrared Survey Explorer (WISE) finds most centaurs are comets.

NASA's IRIS telescope offers first glimpse of sun's mysterious atmosphere

Posted: 25 Jul 2013 11:16 AM PDT

The moment when a telescope first opens its doors represents the culmination of years of work and planning -- while simultaneously laying the groundwork for a wealth of research and answers yet to come. It is a moment of excitement and perhaps even a little uncertainty. On July 17, 2013, the international team of scientists and engineers who supported and built NASA's Interface Region Imaging Spectrograph, or IRIS, all lived through that moment. As the spacecraft orbited around Earth, the door of the telescope opened to view the mysterious lowest layers of the sun's atmosphere and the results thus far are nothing short of amazing. The data is crisp and clear, showing unprecedented detail of this little-observed region.

Image of sun-approaching comet ISON

Posted: 25 Jul 2013 11:15 AM PDT

In this Hubble composite image taken in April 2013, the sun-approaching Comet ISON floats against a seemingly infinite backdrop of numerous galaxies and a handful of foreground stars.

ScienceDaily: Black Holes News

Largest magnetic fields in the universe

Posted: 26 Jul 2013 01:34 AM PDT

ScienceDaily: Cosmic Rays News

Largest magnetic fields in the universe

Posted: 26 Jul 2013 01:34 AM PDT

NASA's Van Allen Probes discover particle accelerator in the heart of Earth’s radiation belts

Posted: 25 Jul 2013 11:07 AM PDT

Scientists have discovered a massive particle accelerator in the heart of one of the harshest regions of near-Earth space, a region of super-energetic, charged particles surrounding the globe called the Van Allen radiation belts. Scientists knew that something in space accelerated particles in the radiation belts to more than 99 percent the speed of light but they didn't know what that something was. New results from NASA's Van Allen Probes now show that the acceleration energy comes from within the belts themselves. Particles inside the belts are sped up by local kicks of energy, buffeting the particles to ever faster speeds, much like a perfectly timed push on a moving swing.

Thursday, July 25, 2013

NASA's WISE Finds Mysterious Centaurs May Be Comets

News release: 2013-234 July 25, 2013

NASA's WISE Finds Mysterious Centaurs May Be Comets

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.php?release=2013-234&cid=release_2013-234

PASADENA, Calf. -- The true identity of centaurs, the small celestial bodies orbiting the sun between Jupiter and Neptune, is one of the enduring mysteries of astrophysics. Are they asteroids or comets? A new study of observations from NASA's Wide-field Infrared Survey Explorer (WISE) finds most centaurs are comets.

Until now, astronomers were not certain whether centaurs are asteroids flung out from the inner solar system or comets traveling in toward the sun from afar. Because of their dual nature, they take their name from the creature in Greek mythology whose head and torso are human and legs are those of a horse.

"Just like the mythical creatures, the centaur objects seem to have a double life," said James Bauer of NASA's Jet Propulsion Laboratory in Pasadena, Calif. Bauer is lead author of a paper published online July 22 in the Astrophysical Journal. "Our data point to a cometary origin for most of the objects, suggesting they are coming from deeper out in the solar system."

"Cometary origin" means an object likely is made from the same material as a comet, may have been an active comet in the past, and may be active again in the future.

The findings come from the largest infrared survey to date of centaurs and their more distant cousins, called scattered disk objects. NEOWISE, the asteroid-hunting portion of the WISE mission, gathered infrared images of 52 centaurs and scattered disk objects. Fifteen of the 52 are new discoveries. Centaurs and scattered disk objects orbit in an unstable belt. Ultimately, gravity from the giant planets will fling them either closer to the sun or farther away from their current locations.

Although astronomers previously observed some centaurs with dusty halos, a common feature of outgassing comets, and NASA's Spitzer Space Telescope also found some evidence for comets in the group, they had not been able to estimate the numbers of comets and asteroids.

Infrared data from NEOWISE provided information on the objects' albedos, or reflectivity, to help astronomers sort the population. NEOWISE can tell whether a centaur has a matte and dark surface or a shiny one that reflects more light. The puzzle pieces fell into place when astronomers combined the albedo information with what was already known about the colors of the objects. Visible-light observations have shown centaurs generally to be either blue-gray or reddish in hue. A blue-gray object could be an asteroid or comet. NEOWISE showed that most of the blue-gray objects are dark, a telltale sign of comets. A reddish object is more likely to be an asteroid.

"Comets have a dark, soot-like coating on their icy surfaces, making them darker than most asteroids," said the study's co-author, Tommy Grav of the Planetary Science Institute in Tucson, Ariz. "Comet surfaces tend to be more like charcoal, while asteroids are usually shinier like the moon."

The results indicate that roughly two-thirds of the centaur population are comets, which come from the frigid outer reaches of our solar system. It is not clear whether the rest are asteroids. The centaur bodies have not lost their mystique entirely, but future research from NEOWISE may reveal their secrets further.

The paper is available online at: http://iopscience.iop.org/0004-637X/773/1/22/ .

JPL, managed by the California Institute of Technology in Pasadena, managed and operated WISE for NASA's Science Mission Directorate. The NEOWISE portion of the project was funded by NASA's Near Earth Object Observation Program. WISE completed its key mission objective, two scans of the entire sky, in 2011 and has been hibernating in space since then.

For more information about the WISE mission, visit: http://www.nasa.gov/wise .

Whitney Clavin 818-354-4673
Jet Propulsion Laboratory, Pasadena, Calif.
whitney.clavin@jpl.nasa.gov

J.D. Harrington 202-358-5241
Headquarters, Washington
j.d.harrington@nasa.gov

- end -

Remove yourself from this mailing.

Remove yourself from all mailings from NASA Jet Propulsion Laboratory.