Showing posts with label nasa universe pictures. Show all posts
Showing posts with label nasa universe pictures. Show all posts

Monday, July 24, 2017

NASA releases New Horizons flyover video

NASA releases New Horizons flyover video:



Pluto Global Color Map


This new, detailed global mosaic color map of Pluto is based on a series of three color filter images obtained by the Ralph/Multispectral Visual Imaging Camera aboard New Horizons during the NASA spacecraft’s close flyby of Pluto in July 2015. The mosaic shows how Pluto’s large-scale color patterns extend beyond the hemisphere facing New Horizons at closest approach, which were imaged at the highest resolution. North is up; Pluto’s equator roughly bisects the band of dark red terrains running across the lower third of the map. Pluto’s giant, informally named Sputnik Planitia glacier – the left half of Pluto’s signature “heart” feature – is at the center of this map. Note: Click on the image to view in the highest resolution. Image & Caption Credit: NASA/JHUAPL/SwRI
Using actual New Horizons data and digital elevation models of Pluto and its largest moon, Charon, mission scientists have created flyover movies that offer spectacular new perspectives of the many unusual features that were discovered and which have reshaped our views of the Pluto system – from a vantage point even closer than the spacecraft itself.

This dramatic Pluto flyover begins over the highlands to the southwest of the great expanse of nitrogen ice plain informally named Sputnik Planitia. The viewer first passes over the western margin of Sputnik, where it borders the dark, cratered terrain of Cthulhu Macula, with the blocky mountain ranges located within the plains seen on the right. The tour moves north past the rugged and fractured highlands of Voyager Terra and then turns southward over Pioneer Terra – which exhibits deep and wide pits – before concluding over the bladed terrain of Tartarus Dorsa in the far east of the encounter hemisphere.

Digital mapping and rendering were performed by Paul Schenk and John Blackwell of the Lunar and Planetary Institute in Houston.



Video courtesy of NASA


The post NASA releases New Horizons flyover video appeared first on SpaceFlight Insider.

NASA prepares its Martian explorers for solar conjunction radio silence

NASA prepares its Martian explorers for solar conjunction radio silence:



solar conjunction


With the Sun sitting between Earth and Mars, called a solar conjunction, NASA will suspend communications with its explorers at the Red Planet for nearly two weeks. Image Credit: NASA / JPL
For more than twenty years, NASA has had explorers surveying the Red Planet. Dutifully, the stalwart robotic travelers have followed commands beamed from their Earth-bound handlers and returned gigabytes of information of their Martian observations.

However, for a few days every 26 months, communication from Earth to Mars takes a Sun-induced break. Beginning July 22, 2017, and lasting through August 1, 2017, NASA will avoid sending commands to its Mars-based craft.



solar conjunction


Animation of a Mars Solar Conjunction. Animation Credit: NASA / JPL

The Sun giveth, the Sun taketh away


While the Sun provides life-supporting energy to Earth and supplies power to solar panels on spacecraft, its highly ionized corona holds a significant potential to disrupt data transmission when it sits between the two planets. Although the two planets won’t be directly obscured by the Sun, the far-reaching effects of its outer layer can still induce data loss.

“Out of caution, we won’t talk to our Mars assets during that period because we expect significant degradation in the communication link, and we don’t want to take a chance that one of our spacecraft would act on a corrupted command,” stated Chad Edwards, manager of the Mars Relay Network Office at NASA’s Jet Propulsion Laboratory (JPL), in a release issued by the agency.

Though commands won’t be sent to Mars during the conjunction window, telemetry will still be sent to Earth. Should data loss occur, the robotic craft can be instructed to repeat its transmission once clear of solar interference.

This command black-out period extends for two days both before and after a solar conjunction event.

Able to work independently


Even though no commands will be sent to Mars during the conjunction, NASA’s rovers and orbiting spacecraft will still have work to do. In fact, engineers have been preparing the explorers far ahead to ensure observations run unabated.

“The vehicles will stay active, carrying out commands sent in advance,” stated JPL’s Mars Program Chief Engineer, Hoppy Price.

While the agency’s two active rovers – Curiosity and Opportunity – will be conducting pre-programmed investigations, they will remain stationary during the blackout.

Although the lack of communications may sound worrisome, all of the orbiters/rovers have already endured at least one Mars Solar Conjunction. Indeed, the Mars Odyssey orbiter will be undergoing its eighth conjunction, while Opportunity holds the surface record at just one less than its orbiting cousin.

“All of these spacecraft are now veterans of conjunction. We know what to expect,” concluded Edwards.



NASA's Mars Science Laboratory rover 'Curiosity' at the Namib Dune in Gale Crater.


Curiosity will remain stationary during the blackout period, but will still conduct investigations. Image Credit: NASA / JPL / MSSS


The post NASA prepares its Martian explorers for solar conjunction radio silence appeared first on SpaceFlight Insider.

Tuesday, July 22, 2014

Comet Found Hiding in Plain Sight

Comet Found Hiding in Plain Sight:

Spitzer Spies a Comet Coma and Tail
With the help of NASA's Spitzer Space Telescope, astronomers have discovered that what was thought to be a large asteroid called Don Quixote is in fact a comet. Image credit: NASA/JPL-Caltech/DLR/NAU
› Full image and caption

September 10, 2013

For 30 years, a large near-Earth asteroid wandered its lone, intrepid path, passing before the scrutinizing eyes of scientists armed with telescopes while keeping something to itself. The object, known as Don Quixote, whose journey stretches to the orbit of Jupiter, now appears to be a comet.


The discovery resulted from an ongoing project coordinated by researchers at Northern Arizona University, Flagstaff, Ariz., using NASA's Spitzer Space Telescope. Through a lot of focused attention and a little luck, they found evidence of comet activity, which had evaded detection for three decades.


The results show that Don Quixote is not, in fact, a dead comet, as previously believed, but it has a faint coma and tail. In fact, this object, the third-biggest near-Earth asteroid known, skirts Earth with an erratic, extended orbit and is "sopping wet," said David Trilling of Northern Arizona University, with large deposits of carbon dioxide and presumably water ice. Don Quixote is about 11 miles (18 kilometers) long.


"This discovery of carbon dioxide emission from Don Quixote required the sensitivity and infrared wavelengths of the Spitzer telescope and would not have been possible using telescopes on the ground," said Michael Mommert, who conducted the research at the German Aerospace Center, Berlin, before moving to Northern Arizona University. This discovery implies that carbon dioxide and water ice might be present on other near-Earth asteroids, as well.


The implications have less to do with a potential impact, which is extremely unlikely in this case, and more with "the origins of water on Earth," Trilling said. Impacts with comets like Don Quixote over geological time may be the source of at least some of it, and the amount on Don Quixote represents about 100 billion tons of water -- roughly the same amount that can be found in Lake Tahoe, Calif.


Mommert presented the results at the European Planetary Science Congress in London on Sept. 10.


Read the full news release from Northern Arizona University at http://news.nau.edu/nau-led-teams-discovers-comet-hiding-in-plain-sight/ .


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

Whitney Clavin 818-354-4673

Jet Propulsion Laboratory, Pasadena, Calif.

whitney.clavin@jpl.nasa.gov


2013-274

'La Nada' Climate Pattern Lingers in the Pacific

'La Nada' Climate Pattern Lingers in the Pacific:

The latest image of sea surface heights in the Pacific Ocean from NASA's Jason-2 satellite
The latest image of sea surface heights in the Pacific Ocean from NASA's Jason-2 satellite shows that the equatorial Pacific Ocean is now in its 16th month of being locked in what some call a neutral, or "La Nada" state.
Image credit: NASA-JPL/Caltech/Ocean Surface Topography Team

› Full image and caption

September 09, 2013

UPDATE - SEPT. 10: After publication of this image on Sept. 9, a small error was discovered in the original processing of the data that were used to generate the Aug. 27, 2013 Jason-2 image. The image has been updated accordingly. The data used to generate the reprocessed image are the same, and the discussion and analysis of the data in the news story below remains unchanged.


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New remote sensing data from NASA's Jason-2 satellite show near-normal sea-surface height conditions across the equatorial Pacific Ocean. This neutral, or "La Nada" event, has stubbornly persisted for 16 months, since spring 2012. Models suggest this pattern will continue through the spring of 2014, according to the National Weather Service's Climate Prediction Center.


"Without an El Niño or La Niña signal present, other, less predictable, climatic factors will govern fall, winter and spring weather conditions," said climatologist Bill Patzert of NASA's Jet Propulsion Laboratory, Pasadena, Calif. "Long-range forecasts are most successful during El Niño and La Niña episodes. The 'in between' ocean state, La Nada, is the dominant condition, and is frustrating for long-range forecasters. It's like driving without a decent road map -- it makes forecasting difficult."


The near-normal conditions are shown in a new image (as areas shaded in green), based on the average of 10 days of data centered on Aug. 27, 2013. The image is available at: http://www.jpl.nasa.gov/spaceimages/details.php?id=pia17454 .


For the past several decades, about half of all years have experienced La Nada conditions, compared to about 20 percent for El Niño and 30 percent for La Niña.


Patzert noted that some of the wettest and driest winters occur during La Nada periods.


"Neutral infers something benign, but in fact if you look at these La Nada years when neither El Niño nor La Niña are present, they can be the most volatile and punishing. As an example, the continuing, deepening drought in the American West is far from 'neutral,'" he said.


The height of the sea water relates, in part, to its temperature, and thus is an indicator of the amount of heat stored in the ocean below. As the ocean warms, its level rises; as it cools, its level falls. Yellow and red areas indicate where the waters are relatively warmer and have expanded above normal sea level, while green (which dominates in this image) indicates near-normal sea level, and blue and purple areas show where the waters are relatively colder and sea level is lower than normal. Above-normal height variations along the equatorial Pacific indicate El Niño conditions, while below-normal height variations indicate La Niña conditions. The temperature of the upper ocean can have a significant influence on weather patterns and climate. For a more detailed explanation of what this type of image means, visit: http://sealevel.jpl.nasa.gov/science/elninopdo/latestdata/.


This latest image highlights the processes that occur on time scales of more than a year, but usually less than 10 years, such as El Niño and La Niña. These processes are known as the interannual ocean signal. To show that signal, scientists refined data for this image by removing trends over the past 20 years, seasonal variations and time-averaged signals of large-scale ocean circulation.


NASA scientists will continue to monitor this persistent La Nada event to see what the Pacific Ocean has in store next for the world's climate.


The comings and goings of El Niño, La Niña and La Nada are part of the long-term, evolving state of global climate, for which measurements of sea surface height are a key indicator. Jason-2 is a joint effort between NASA, the National Oceanic and Atmospheric Administration (NOAA), the French Space Agency Centre National d'Etudes Spatiales (CNES) and the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT). JPL manages the U.S. portion of Jason-2 for NASA's Science Mission Directorate, Washington, D.C.
In early 2015, NASA and its international partners CNES, NOAA and EUMETSAT will launch Jason-3, which will extend the timeline of ocean surface topography measurements begun by the Topex/Poseidon and Jason 1 and 2 satellites. Jason-3 will make highly detailed measurements of sea level on Earth to gain insight into ocean circulation and climate change.


For more on NASA's satellite altimetry programs, visit: http://sealevel.jpl.nasa.gov.

Alan Buis 818-354-0474

Jet Propulsion Laboratory, Pasadena, Calif.

alan.buis@jpl.nasa.gov


2013-272

Coldest Brown Dwarfs Blur Star, Planet Lines

Coldest Brown Dwarfs Blur Star, Planet Lines:

Brown Dwarf Backyardigans
The locations of brown dwarfs discovered by NASA's Wide-field Infrared Survey Explorer, or WISE, and mapped by NASA's Spitzer Space Telescope, are shown in this diagram. The view is from a vantage point about 100 light-years away from the sun, looking back toward the constellation Orion. Image credit: NASA/JPL-Caltech
› Full image and caption

September 05, 2013

In 2011, astronomers on the hunt for the coldest star-like celestial bodies discovered a new class of such objects using NASA's Wide-Field Infrared Survey Explorer (WISE) space telescope. But until now, no one knew exactly how cool the bodies' surfaces really are. In fact, some evidence suggested they could be at room temperature.


A new study using data from NASA's Spitzer Space Telescope shows that while these so-called brown dwarfs are indeed the coldest known free-floating celestial bodies, they are warmer than previously thought, with surface temperatures ranging from about 250 to 350 degrees Fahrenheit (125 to 175 degrees Celsius). By comparison, the sun has a surface temperature of about 10,340 degrees Fahrenheit (5,730 degrees Celsius).


To reach these surface temperatures after cooling for billions of years, these objects would have to have masses of only five to 20 times that of Jupiter. Unlike the sun, the only source of energy for these coldest of brown dwarfs is from their gravitational contraction, which depends directly on their mass. The sun is powered by the conversion of hydrogen to helium; these brown dwarfs are not hot enough for this type of "nuclear burning" to occur.


The findings help researchers understand how planets and stars form.


"If one of these objects were found orbiting a star, there is a good chance that it would be called a planet," said Trent Dupuy, a Hubble Fellow at the Harvard-Smithsonian Center for Astrophysics and a co-author of the study, appearing online Sept. 5 in the journal Science Express. But because they probably formed on their own and not in a planet-forming disk orbiting a more massive star, astronomers still call these objects brown dwarfs even if their mass is of planetary size.


Characterizing these cold brown dwarfs is challenging because they emit most of their light at infrared wavelengths and are very faint due to their small size and low temperature.


To get accurate temperatures, astronomers need to know the distances to these objects. "We wanted to find out if they were colder, fainter and nearby, or if they were warmer, brighter and more distant," explains Dupuy.


Using Spitzer, the team determined that the brown dwarfs in question are located at distances 20 to 50 light-years away.


To determine the distances to these objects, the team measured their parallax -- the apparent change in position against background stars over time. As Spitzer orbits the sun, its perspective changes and nearby objects appear to shift back and forth slightly. The same effect occurs if you hold up a finger in front of your face and close one eye and then the other. The position of your finger seems to shift when viewed against the distant background.


But even for these relatively nearby brown dwarfs, the parallax motion is small. "To be able to determine accurate distances, our measurements had to be the same precision as knowing the position of a firefly to within 1 inch (2.5 centimeters) from 200 miles (320 kilometers) away," explained Adam Kraus, professor at the University of Texas at Austin and the study's other co-author.


The new data also present new puzzles to astronomers who study cool, planet-like atmospheres. Unlike warmer brown dwarfs and stars, the observable properties of these objects don't seem to correlate as strongly with temperature. This suggests increased roles for other factors, such as convective mixing, in driving the chemistry at the surface.


This study examined the initial sample of the coldest brown dwarfs discovered in the WISE survey data. Additional objects discovered in the past two years remain to be studied, and scientists hope they will shed light on some of these outstanding issues.


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 the California Institute of Technology in Pasadena. Data are archived at the Infrared Science Archive housed at the Infrared Processing and Analysis Center at Caltech. Caltech manages JPL for NASA.


For more information about Spitzer, visit http://spitzer.caltech.edu and http://www.nasa.gov/spitzer.

Whitney Clavin 818-354-4673

Jet Propulsion Laboratory, Pasadena, Calif.

whitney.clavin@jpl.nasa.gov

2013-271

How Do We Know When Voyager Reaches Interstellar Space?

How Do We Know When Voyager Reaches Interstellar Space?:

This artist's concept shows NASA's Voyager spacecraft against a backdrop of stars.
You Are Here, Voyager: This artist's concept puts huge solar system distances in perspective. The scale bar is measured in astronomical units (AU), with each set distance beyond 1 AU representing 10 times the previous distance. Each AU is equal to the distance from the sun to the Earth. It took from 1977 to 2013 for Voyager 1 to reach the edge of interstellar space.
Image Credit:
NASA/JPL-Caltech
› Full image and caption

September 12, 2013

Whether and when NASA's Voyager 1 spacecraft, humankind's most distant object, broke through to interstellar space, the space between stars, has been a thorny issue. For the last year, claims have surfaced every few months that Voyager 1 has "left our solar system." Why has the Voyager team held off from saying the craft reached interstellar space until now?


"We have been cautious because we're dealing with one of the most important milestones in the history of exploration," said Voyager Project Scientist Ed Stone of the California Institute of Technology in Pasadena. "Only now do we have the data -- and the analysis -- we needed."


Basically, the team needed more data on plasma, which is ionized gas, the densest and slowest moving of charged particles in space. (The glow of neon in a storefront sign is an example of plasma.) Plasma is the most important marker that distinguishes whether Voyager 1 is inside the solar bubble, known as the heliosphere, which is inflated by plasma that streams outward from our sun, or in interstellar space and surrounded by material ejected by the explosion of nearby giant stars millions of years ago. Adding to the challenge: they didn't know how they'd be able to detect it.


"We looked for the signs predicted by the models that use the best available data, but until now we had no measurements of the plasma from Voyager 1," said Stone.


Scientific debates can take years, even decades to settle, especially when more data are needed. It took decades, for instance, for scientists to understand the idea of plate tectonics, the theory that explains the shape of Earth's continents and the structure of its sea floors. First introduced in the 1910s, continental drift and related ideas were controversial for years. A mature theory of plate tectonics didn't emerge until the 1950s and 1960s. Only after scientists gathered data showing that sea floors slowly spread out from mid-ocean ridges did they finally start accepting the theory. Most active geophysicists accepted plate tectonics by the late 1960s, though some never did.


Voyager 1 is exploring an even more unfamiliar place than our Earth's sea floors -- a place more than 11 billion miles (17 billion kilometers) away from our sun. It has been sending back so much unexpected data that the science team has been grappling with the question of how to explain all the information. None of the handful of models the Voyager team uses as blueprints have accounted for the observations about the transition between our heliosphere and the interstellar medium in detail. The team has known it might take months, or longer, to understand the data fully and draw their conclusions.


"No one has been to interstellar space before, and it's like traveling with guidebooks that are incomplete," said Stone. "Still, uncertainty is part of exploration. We wouldn't go exploring if we knew exactly what we'd find."


The two Voyager spacecraft were launched in 1977 and, between them, had visited Jupiter, Saturn, Uranus and Neptune by 1989. Voyager 1's plasma instrument, which measures the density, temperature and speed of plasma, stopped working in 1980, right after its last planetary flyby. When Voyager 1 detected the pressure of interstellar space on our heliosphere in 2004, the science team didn't have the instrument that would provide the most direct measurements of plasma. Instead, they focused on the direction of the magnetic field as a proxy for source of the plasma. Since solar plasma carries the magnetic field lines emanating from the sun and interstellar plasma carries interstellar magnetic field lines, the directions of the solar and interstellar magnetic fields were expected to differ.


Most models told the Voyager science team to expect an abrupt change in the magnetic field direction as Voyager switched from the solar magnetic field lines inside our solar bubble to those in interstellar space. The models also said to expect the levels of charged particles originating from inside the heliosphere to drop and the levels of galactic cosmic rays, which originate outside the heliosphere, to jump.


In May 2012, the number of galactic cosmic rays made its first significant jump, while some of the inside particles made their first significant dip. The pace of change quickened dramatically on July 28, 2012. After five days, the intensities returned to what they had been. This was the first taste of a new region, and at the time Voyager scientists thought the spacecraft might have briefly touched the edge of interstellar space.


By Aug. 25, when, as we now know, Voyager 1 entered this new region for good, all the lower-energy particles from inside zipped away. Some inside particles dropped by more than a factor of 1,000 compared to 2004. The levels of galactic cosmic rays jumped to the highest of the entire mission. These would be the expected changes if Voyager 1 had crossed the heliopause, which is the boundary between the heliosphere and interstellar space. However, subsequent analysis of the magnetic field data revealed that even though the magnetic field strength jumped by 60 percent at the boundary, the direction changed less than 2 degrees. This suggested that Voyager 1 had not left the solar magnetic field and had only entered a new region, still inside our solar bubble, that had been depleted of inside particles.


Then, in April 2013, scientists got another piece of the puzzle by chance. For the first eight years of exploring the heliosheath, which is the outer layer of the heliosphere, Voyager's plasma wave instrument had heard nothing. But the plasma wave science team, led by Don Gurnett and Bill Kurth at the University of Iowa, Iowa City, had observed bursts of radio waves in 1983 to 1984 and again in 1992 to 1993. They deduced these bursts were produced by the interstellar plasma when a large outburst of solar material would plow into it and cause it to oscillate. It took about 400 days for such solar outbursts to reach interstellar space, leading to an estimated distance of 117 to 177 AU (117 to 177 times the distance from the sun to the Earth) to the heliopause. They knew, though, that they would be able to observe plasma oscillations directly once Voyager 1 was surrounded by interstellar plasma.


Then on April 9, 2013, it happened: Voyager 1's plasma wave instrument picked up local plasma oscillations. Scientists think they probably stemmed from a burst of solar activity from a year before, a burst that has become known as the St. Patrick's Day Solar Storms. The oscillations increased in pitch through May 22 and indicated that Voyager was moving into an increasingly dense region of plasma. This plasma had the signatures of interstellar plasma, with a density more than 40 times that observed by Voyager 2 in the heliosheath.


Gurnett and Kurth began going through the recent data and found a fainter, lower-frequency set of oscillations from Oct. 23 to Nov. 27, 2012. When they extrapolated back, they deduced that Voyager had first encountered this dense interstellar plasma in August 2012, consistent with the sharp boundaries in the charged particle and magnetic field data on August 25.


Stone called three meetings of the Voyager team. They had to decide how to define the boundary between our solar bubble and interstellar space and how to interpret all the data Voyager 1 had been sending back. There was general agreement Voyager 1 was seeing interstellar plasma, based on the results from Gurnett and Kurth, but the sun still had influence. One persisting sign of solar influence, for example, was the detection of outside particles hitting Voyager from some directions more than others. In interstellar space, these particles would be expected to hit Voyager uniformly from all directions.


"Now that we had actual measurements of the plasma environment - by way of an unexpected outburst from the sun - we had to reconsider why there was still solar influence on the magnetic field and plasma in interstellar space," Stone said. "The path to interstellar space has been a lot more complicated than we imagined."


Stone discussed with the Voyager science group whether they thought Voyager 1 had crossed the heliopause. What should they call the region were Voyager 1 is?


"In the end, there was general agreement that Voyager 1 was indeed outside in interstellar space," Stone said. "But that location comes with some disclaimers - we're in a mixed, transitional region of interstellar space. We don't know when we'll reach interstellar space free from the influence of our solar bubble."


So, would the team say Voyager 1 has left the solar system? Not exactly - and that's part of the confusion. Since the 1960s, most scientists have defined our solar system as going out to the Oort Cloud, where the comets that swing by our sun on long timescales originate. That area is where the gravity of other stars begins to dominate that of the sun. It will take about 300 years for Voyager 1 to reach the inner edge of the Oort Cloud and possibly about 30,000 years to fly beyond it. Informally, of course, "solar system" typically means the planetary neighborhood around our sun. Because of this ambiguity, the Voyager team has lately favored talking about interstellar space, which is specifically the space between each star's realm of plasma influence.


"What we can say is Voyager 1 is bathed in matter from other stars," Stone said. "What we can't say is what exact discoveries await Voyager's continued journey. No one was able to predict all of the details that Voyager 1 has seen. So we expect more surprises."


Voyager 1, which is working with a finite power supply, has enough electrical power to keep operating the fields and particles science instruments through at least 2020, which will mark 43 years of continual operation. At that point, mission managers will have to start turning off these instruments one by one to conserve power, with the last one turning off around 2025.


Voyager 1 will continue sending engineering data for a few more years after the last science instrument is turned off, but after that it will be sailing on as a silent ambassador. In about 40,000 years, it will be closer to the star AC +79 3888 than our own sun. (AC +79 3888 is traveling toward us faster than we are traveling towards it, so while Alpha Centauri is the next closest star now, it won't be in 40,000 years.) And for the rest of time, Voyager 1 will continue orbiting around the heart of the Milky Way galaxy, with our sun but a tiny point of light among many.


The Voyager spacecraft were built and continue to be operated by NASA's Jet Propulsion Laboratory, in Pasadena, Calif. Caltech manages JPL for NASA. The Voyager missions are a part of NASA's Heliophysics System Observatory, sponsored by the Heliophysics Division of the Science Mission Directorate at NASA Headquarters in Washington.


For more information about Voyager, visit: http://www.nasa.gov/voyager and http://voyager.jpl.nasa.gov.

Jia-Rui Cook 818-354-0850

Jet Propulsion Laboratory, Pasadena, Calif.

jccook@jpl.nasa.gov


2013-278

NASA Spacecraft Embarks on Historic Journey Into Interstellar Space

NASA Spacecraft Embarks on Historic Journey Into Interstellar Space:

Voyager 1 Entering Interstellar Space
The Space Between: This artist's concept shows the Voyager 1 spacecraft entering the space between stars. Interstellar space is dominated by plasma, ionized gas (illustrated here as brownish haze), that was thrown off by giant stars millions of years ago. Image credit: NASA/JPL-Caltech
› Full image and caption

September 12, 2013

PASADENA, Calif. -- NASA's Voyager 1 spacecraft officially is the first human-made object to venture into interstellar space. The 36-year-old probe is about 12 billion miles (19 billion kilometers) from our sun.


New and unexpected data indicate Voyager 1 has been traveling for about one year through plasma, or ionized gas, present in the space between stars. Voyager is in a transitional region immediately outside the solar bubble, where some effects from our sun are still evident. A report on the analysis of this new data, an effort led by Don Gurnett and the plasma wave science team at the University of Iowa, Iowa City, is published in Thursday's edition of the journal Science.


"Now that we have new, key data, we believe this is mankind's historic leap into interstellar space," said Ed Stone, Voyager project scientist based at the California Institute of Technology, Pasadena. "The Voyager team needed time to analyze those observations and make sense of them. But we can now answer the question we've all been asking -- 'Are we there yet?' Yes, we are."


Voyager 1 first detected the increased pressure of interstellar space on the heliosphere, the bubble of charged particles surrounding the sun that reaches far beyond the outer planets, in 2004. Scientists then ramped up their search for evidence of the spacecraft's interstellar arrival, knowing the data analysis and interpretation could take months or years.


Voyager 1 does not have a working plasma sensor, so scientists needed a different way to measure the spacecraft's plasma environment to make a definitive determination of its location. A coronal mass ejection, or a massive burst of solar wind and magnetic fields, that erupted from the sun in March 2012 provided scientists the data they needed. When this unexpected gift from the sun eventually arrived at Voyager 1's location 13 months later, in April 2013, the plasma around the spacecraft began to vibrate like a violin string. On April 9, Voyager 1's plasma wave instrument detected the movement. The pitch of the oscillations helped scientists determine the density of the plasma. The particular oscillations meant the spacecraft was bathed in plasma more than 40 times denser than what they had encountered in the outer layer of the heliosphere. Density of this sort is to be expected in interstellar space.


The plasma wave science team reviewed its data and found an earlier, fainter set of oscillations in October and November 2012. Through extrapolation of measured plasma densities from both events, the team determined Voyager 1 first entered interstellar space in August 2012.


"We literally jumped out of our seats when we saw these oscillations in our data -- they showed us the spacecraft was in an entirely new region, comparable to what was expected in interstellar space, and totally different than in the solar bubble," Gurnett said. "Clearly we had passed through the heliopause, which is the long-hypothesized boundary between the solar plasma and the interstellar plasma."


The new plasma data suggested a timeframe consistent with abrupt, durable changes in the density of energetic particles that were first detected on Aug. 25, 2012. The Voyager team generally accepts this date as the date of interstellar arrival. The charged particle and plasma changes were what would have been expected during a crossing of the heliopause.


"The team's hard work to build durable spacecraft and carefully manage the Voyager spacecraft's limited resources paid off in another first for NASA and humanity," said Suzanne Dodd, Voyager project manager, based at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "We expect the fields and particles science instruments on Voyager will continue to send back data through at least 2020. We can't wait to see what the Voyager instruments show us next about deep space."


Voyager 1 and its twin, Voyager 2, were launched 16 days apart in 1977. Both spacecraft flew by Jupiter and Saturn. Voyager 2 also flew by Uranus and Neptune. Voyager 2, launched before Voyager 1, is the longest continuously operated spacecraft. It is about 9.5 billion miles (15 billion kilometers) away from our sun.


Voyager mission controllers still talk to or receive data from Voyager 1 and Voyager 2 every day, though the emitted signals are currently very dim, at about 23 watts -- the power of a refrigerator light bulb. By the time the signals get to Earth, they are a fraction of a billion-billionth of a watt. Data from Voyager 1's instruments are transmitted to Earth typically at 160 bits per second, and captured by 34- and 70-meter NASA Deep Space Network stations. Traveling at the speed of light, a signal from Voyager 1 takes about 17 hours to travel to Earth. After the data are transmitted to JPL and processed by the science teams, Voyager data are made publicly available.


"Voyager has boldly gone where no probe has gone before, marking one of the most significant technological achievements in the annals of the history of science, and adding a new chapter in human scientific dreams and endeavors," said John Grunsfeld, NASA's associate administrator for science in Washington. "Perhaps some future deep space explorers will catch up with Voyager, our first interstellar envoy, and reflect on how this intrepid spacecraft helped enable their journey."


Scientists do not know when Voyager 1 will reach the undisturbed part of interstellar space where there is no influence from our sun. They also are not certain when Voyager 2 is expected to cross into interstellar space, but they believe it is not very far behind.


JPL built and operates the twin Voyager spacecraft. The Voyagers Interstellar Mission is a part of NASA's Heliophysics System Observatory, sponsored by the Heliophysics Division of NASA's Science Mission Directorate in Washington. NASA's Deep Space Network, managed by JPL, is an international network of antennas that supports interplanetary spacecraft missions and radio and radar astronomy observations for the exploration of the solar system and the universe. The network also supports selected Earth-orbiting missions.


The cost of the Voyager 1 and Voyager 2 missions -- including launch, mission operations and the spacecraft's nuclear batteries, which were provided by the Department of Energy -- is about $988 million through September.


For a sound file of the oscillations detected by Voyager in interstellar space, animations and other information, visit: http://www.nasa.gov/voyager and http://www.jpl.nasa.gov/interstellarvoyager/ .


For an image of the radio signal from Voyager 1 on Feb. 21 by the National Radio Astronomy Observatory's Very Long Baseline Array, which links telescopes from Hawaii to St. Croix, visit:
http://www.nrao.edu .

Jia-Rui C. Cook/D.C. Agle 818-354-0850/818-393-9011

Jet Propulsion Laboratory, Pasadena, Calif.

jccook@jpl.nasa.gov


Dwayne Brown 202-358-1726

Headquarters, Washington

dwayne.c.brown@nasa.gov


2013-277

NASA News Conference Today to Discuss Voyager Spacecraft

NASA News Conference Today to Discuss Voyager Spacecraft:

Voyager in Space
This artist's concept shows NASA's Voyager spacecraft against a backdrop of stars. Image credit: NASA/JPL-Caltech
› Full image and caption

September 11, 2013

PASADENA, Calif. - NASA will host a news conference today at 11 a.m. PDT (2 p.m. EDT), to discuss NASA's Voyager mission. It is related to a paper to be published in the journal Science, which is embargoed until 11 a.m. PDT (2 p.m. EDT).


The briefing will be held at NASA Headquarters in Washington and air live on NASA Television and the agency's website.


During the news conference, the public may send questions via Twitter to #AskNASA.


For NASA TV streaming video, scheduling and downlink information, visit: http://www.nasa.gov/ntv .


The event will also be streamed live on Ustream at: http://www.ustream.tv/nasajpl2 .


For information about the Voyager mission, visit: http://www.nasa.gov/voyager .

DC Agle/Jia-Rui Cook 818-393-9011/818-354-0850

Jet Propulsion Laboratory, Pasadena, Calif.

agle@jpl.nasa.gov/jccook@jpl.nasa.gov


Dwayne Brown 202-358-1726

NASA Headquarters, Washington

dwayne.c.brown@nasa.gov


2013-276b

NASA Invites Social Media Fans to Earth Science Event

NASA Invites Social Media Fans to Earth Science Event:

This view of Earth comes from NASA's Moderate Resolution Imaging Spectroradiometer aboard the Terra satellite.
This view of Earth comes from NASA's Moderate Resolution Imaging Spectroradiometer aboard the Terra satellite. Larger image
› Larger image


September 16, 2013

PASADENA, Calif. - NASA is inviting its social media followers to apply for participation in a two-day NASA Social on Nov. 4 and 5 at the agency's Jet Propulsion Laboratory in Pasadena, Calif. The event will highlight NASA and JPL's role in studying Earth and its climate and will preview three Earth-observing missions JPL is preparing for launch in 2014.


The event will offer people who connect with NASA through Twitter, Facebook, Google+ and other social networks the opportunity to interact with scientists and engineers working on upcoming missions and participate in hands-on demonstrations. Participants will also interact with fellow tweeps, space enthusiasts and members of NASA's social media team. They will get a behind-the-scenes tour of JPL, including:


-- The Spacecraft Assembly Facility, where hardware for two upcoming Earth missions is currently under construction. This clean room is also where NASA's Voyager and Cassini spacecraft and the Curiosity, Opportunity and Spirit Mars rovers were built and tested.
-- The JPL Earth Science Center, where data from many of the agency's Earth-observing missions are showcased in interactive displays.
-- The Mission Control Center of NASA's Deep Space Network, where engineers "talk to" spacecraft across the solar system and in interstellar space.
-- The JPL Mars Yard, where engineers and scientists test engineering models of NASA's Curiosity rover in a sandy, Mars-like environment.


Registration for the NASA Social is open until noon PDT (3 p.m. EDT) on Wednesday, Sept. 18. NASA will randomly select at least 100 participants from online registrations.
More information on NASA Socials and the application for the Nov. 4/5 event are online at: http://www.nasa.gov/social .


The two NASA/JPL Earth-observing missions being assembled at JPL are the Soil Moisture Active Passive (SMAP) spacecraft and ISS-RapidScat. SMAP will produce global maps of soil moisture for tracking water availability around our planet. ISS-RapidScat is a scatterometer instrument that will be mounted outside the International Space Station to measure ocean surface wind speeds and directions. ISS-RapidScat is scheduled to launch first, in April 2014, with SMAP scheduled to launch in October 2014.


A third NASA/JPL Earth mission, the Orbiting Carbon Observatory-2 (OCO-2), scheduled to launch in July 2014, is in final assembly and testing at an Orbital Sciences Corp. facility in Gilbert, Ariz. The mission will be NASA's first dedicated Earth remote-sensing satellite to study atmospheric carbon dioxide from space.


To join and track the conversation online during the NASA Socials, follow the hashtag #NASASocial.


More information about connecting and collaborating with NASA is at: http://www.nasa.gov/connect .


For more on SMAP, visit: http://smap.jpl.nasa.gov/ .


For more on ISS-RapidScat, visit: http://www.nasa.gov/mission_pages/station/research/experiments/ISSRapidScat.html and http://winds.jpl.nasa.gov/missions/RapidScat/ .


For more on OCO-2, visit: http://oco.jpl.nasa.gov/ .


The California Institute of Technology in Pasadena manages JPL for NASA.

Courtney O'Connor 818-354-2274

Jet Propulsion Laboratory, Pasadena, Calif.

oconnor@jpl.nasa.gov


John Yembrick/Jason Townsend 650-604-2065 / 202-358-0359

NASA Headquarters, Washington

john.yembrick@nasa.gov / jason.c.townsend@nasa.gov


2013-280

NASA's Deep Space Comet Hunter Mission Comes to an End

NASA's Deep Space Comet Hunter Mission Comes to an End:

Artist's concept of NASA's Deep Impact spacecraft.
Artist's concept of NASA's Deep Impact spacecraft. Image Credit: NASA/JPL-Caltech.
› Larger image

September 20, 2013

PASADENA, Calif. - After almost 9 years in space that included an unprecedented July 4th impact and subsequent flyby of a comet, an additional comet flyby, and the return of approximately 500,000 images of celestial objects, NASA's Deep Impact mission has ended.

The project team at NASA's Jet Propulsion Laboratory in Pasadena, Calif., has reluctantly pronounced the mission at an end after being unable to communicate with the spacecraft for over a month. The last communication with the probe was Aug. 8. Deep Impact was history's most traveled comet research mission, going about 4.7 billion miles (7.58 billion kilometers).

"Deep Impact has been a fantastic, long-lasting spacecraft that has produced far more data than we had planned," said Mike A'Hearn, the Deep Impact principal investigator at the University of Maryland in College Park. "It has revolutionized our understanding of comets and their activity."

Deep Impact successfully completed its original bold mission of six months in 2005 to investigate both the surface and interior composition of a comet, and a subsequent extended mission of another comet flyby and observations of planets around other stars that lasted from July 2007 to December 2010. Since then, the spacecraft has been continually used as a space-borne planetary observatory to capture images and other scientific data on several targets of opportunity with its telescopes and instrumentation.

Launched in January 2005, the spacecraft first traveled about 268 million miles (431 million kilometers) to the vicinity of comet Tempel 1. On July 3, 2005, the spacecraft deployed an impactor into the path of comet to essentially be run over by its nucleus on July 4. This caused material from below the comet's surface to be blasted out into space where it could be examined by the telescopes and instrumentation of the flyby spacecraft. Sixteen days after that comet encounter, the Deep Impact team placed the spacecraft on a trajectory to fly back past Earth in late December 2007 to put it on course to encounter another comet, Hartley 2 in November 2010.

"Six months after launch, this spacecraft had already completed its planned mission to study comet Tempel 1," said Tim Larson, project manager of Deep Impact at JPL. "But the science team kept finding interesting things to do, and through the ingenuity of our mission team and navigators and support of NASA's Discovery Program, this spacecraft kept it up for more than eight years, producing amazing results all along the way."

The spacecraft's extended mission culminated in the successful flyby of comet Hartley 2 on Nov. 4, 2010. Along the way, it also observed six different stars to confirm the motion of planets orbiting them, and took images and data of Earth, the moon and Mars. These data helped to confirm the existence of water on the moon, and attempted to confirm the methane signature in the atmosphere of Mars. One sequence of images is a breathtaking view of the moon transiting across the face of Earth.

In January 2012, Deep Impact performed imaging and accessed the composition of distant comet C/2009 P1 (Garradd). It took images of comet ISON this year and collected early images of ISON in June.

After losing contact with the spacecraft last month, mission controllers spent several weeks trying to uplink commands to reactivate its onboard systems. Although the exact cause of the loss is not known, analysis has uncovered a potential problem with computer time tagging that could have led to loss of control for Deep Impact's orientation. That would then affect the positioning of its radio antennas, making communication difficult, as well as its solar arrays, which would in turn prevent the spacecraft from getting power and allow cold temperatures to ruin onboard equipment, essentially freezing its battery and propulsion systems.

"Despite this unexpected final curtain call, Deep Impact already achieved much more than ever was envisioned," said Lindley Johnson, the Discovery Program Executive at NASA Headquarters, and the Program Executive for the mission since a year before it launched. "Deep Impact has completely overturned what we thought we knew about comets and also provided a treasure trove of additional planetary science that will be the source data of research for years to come."

The mission is part of the Discovery Program managed at NASA's Marshall Space Flight Center in Huntsville, Ala. JPL manages the Deep Impact mission for NASA's Science Mission Directorate in Washington. Ball Aerospace & Technologies Corp. of Boulder, Colo., built the spacecraft. The California Institute of Technology in Pasadena manages JPL for NASA.

To find out more about Deep Impact's scientific results, visit:

http://www.jpl.nasa.gov/news/news.php?release=2013-286

For more information about Deep Impact, visit:

http://www.nasa.gov/deepimpact

D.C. Agle 818-393-9011

Jet Propulsion Laboratory, Pasadena, Calif.

agle@jpl.nasa.gov

Dwayne Brown 202-358-1726

NASA Headquarters, Washington

dwayne.c.brown@nasa.gov


Lee Tune 301-405-4679
University of Maryland, College Park, Md.
ltune@umd.edu

2013-287

How Engineers Revamped Spitzer to Probe Exoplanets

How Engineers Revamped Spitzer to Probe Exoplanets:

Spitzer Trains Its Eyes on Exoplanets
Over its ten years in space, NASA's Spitzer Space Telescope has evolved into a premier tool for studying exoplanets. The engineers and scientists behind Spitzer did not have this goal in mind when they designed the observatory back in the 1990s. But thanks to its extraordinary stability, and a series of engineering reworks after launch, Spitzer now has observational powers far beyond its original limits and expectations. Image credit: NASA/JPL-Caltech
› Full image and caption

September 24, 2013

Now approaching its 10th anniversary, NASA's Spitzer Space Telescope has evolved into a premier observatory for an endeavor not envisioned in its original design: the study of worlds around other stars, called exoplanets. While the engineers and scientists who built Spitzer did not have this goal in mind, their visionary work made this unexpected capability possible. Thanks to the extraordinary stability of its design and a series of subsequent engineering reworks, the space telescope now has observational powers far beyond its original limits and expectations.


"When Spitzer launched back in 2003, the idea that we would use it to study exoplanets was so crazy that no one considered it," said Sean Carey of NASA's Spitzer Science Center at the California Institute of Technology in Pasadena. "But now the exoplanet science work has become a cornerstone of what we do with the telescope."


Spitzer views the universe in the infrared light that is a bit less energetic than the light our eyes can see. Infrared light can easily pass through stray cosmic gas and dust, allowing researchers to peer into dusty stellar nurseries, the centers of galaxies, and newly forming planetary systems.


This infrared vision of Spitzer's also translates into exoplanet snooping. When an exoplanet crosses or "transits" in front of its star, it blocks out a tiny fraction of the starlight. These mini-eclipses as glimpsed by Spitzer reveal the size of an alien world.


Exoplanets emit infrared light as well, which Spitzer can capture to learn about their atmospheric compositions. As an exoplanet orbits its sun, showing different regions of its surface to Spitzer's cameras, changes in overall infrared brightness can speak to the planet's climate. A decrease in brightness as the exoplanet then goes behind its star can also provide a measurement of the world's temperature.


While the study of the formation of stars and the dusty environments from which planets form had always been a cornerstone of Spitzer's science program, its exoplanet work only became possible by reaching an unprecedented level of sensitivity, beyond its original design specifications.


Researchers had actually finalized the telescope's design in 1996 before any transiting exoplanets had even been discovered. The high degree of precision in measuring brightness changes needed for observing transiting exoplanets was not considered feasible in infrared because no previous infrared instrument had offered anything close to what was needed.


Nevertheless, Spitzer was built to have excellent control over unwanted temperature variations and a better star-targeting pointing system than thought necessary to perform its duties. Both of these foresighted design elements have since paid dividends in obtaining the extreme precision required for studying transiting exoplanets.


The fact that Spitzer can still do any science work at all still can be credited to some early-in-the-game, innovative thinking. Spitzer was initially loaded with enough coolant to keep its three temperature-sensitive science instruments running for at least two-and-a-half years. This "cryo" mission ended up lasting more than five-and-a-half-years before exhausting the coolant.


But Spitzer's engineers had a built-in backup plan. A passive cooling system has kept one set of infrared cameras humming along at a super-low operational temperature of minus 407 degrees Fahrenheit (minus 244 Celsius, or 29 degrees above absolute zero). The infrared cameras have continued operating at full sensitivity, letting Spitzer persevere in a "warm" extended mission, so to speak, though still extremely cold by Earthly standards.


To stay so cool, Spitzer is painted black on the side that faces away from the sun, which enables the telescope to radiate away a maximum amount of heat into space. On the sun-facing side, Spitzer has a shiny coating that reflects as much of the heat from the sun and solar panels as possible. It is the first infrared telescope to use this innovative design and has set the standard for subsequent missions.


Fully transitioning Spitzer into an exoplanet spy required some clever modifications in-flight as well, long after it flew beyond the reach of human hands into an Earth-trailing orbit. Despite the telescope's excellent stability, a small "wobbling" remained as it pointed at target stars. The cameras also exhibited small brightness fluctuations when a star moved slightly across an individual pixel of the camera. The wobble, coupled with the small variation in the cameras, produced a periodic brightening and dimming of light from a star, making the delicate task of measuring exoplanet transits that much more difficult.


To tackle these issues, engineers first began looking into a source for the wobble. They noticed that the telescope's trembling followed an hourly cycle. This cycle, it turned out, coincided with that of a heater, which kicks on periodically to keep a battery aboard Spitzer at a certain temperature. The heater caused a strut between the star trackers and telescope to flex a bit, making the position of the telescope wobble compared to the stars being tracked.


Ultimately, in October 2010, the engineers figured out that the heater did not need to be cycled through its full hour and temperature range -- 30 minutes and about 50 percent of the heat would do. This tweak served to cut the telescope's wobble in half.


Spitzer's engineers and scientists were still not satisfied, however. In September 2011, they succeeded in repurposing Spitzer's Pointing Control Reference Sensor "Peak-Up" camera. This camera was used during the original cryo mission to put gathered infrared light precisely into a spectrometer and to perform routine calibrations of the telescope's star-trackers, which help point the observatory. The telescope naturally wobbles back and forth a bit as it stares at a particular target star or object. Given this unavoidable jitter, being able to control where light goes within the infrared camera is critical for obtaining precise measurements. The engineers applied the Peak-Up to the infrared camera observations, thus allowing astronomers to place stars precisely on the center of a camera pixel.


Since repurposing the Peak-Up Camera, astronomers have taken this process even further, by carefully "mapping" the quirks of a single pixel within the camera. They have essentially found a "sweet spot" that returns the most stable observations. About 90 percent of Spitzer's exoplanet observations are finely targeted to a sub-pixel level, down to a particular quarter of a pixel. "We can use the Peak-Up camera to position ourselves very precisely on the camera and put light right on the best part of a pixel," said Carey. "So you put the light on the sweet spot and just let Spitzer stare."


These three accomplishments -- the modified heater cycling, repurposed Peak-Up camera and the in-depth characterization of individual pixels in the camera -- have more than doubled Spitzer's stability and targeting, giving the telescope exquisite sensitivity when it comes to taking exoplanet measurements.


"Because of these engineering modifications, Spitzer has been transformed into an exoplanet-studying telescope," said Carey. "We expect plenty of great exoplanetary science to come from Spitzer in the future."


NASA's Jet Propulsion Laboratory in Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate in Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. Data are archived at the Infrared Science Archive housed at the Infrared Processing and Analysis Center at Caltech. Caltech manages JPL for NASA.


For more information about Spitzer, visit: http://www.nasa.gov/spitzer or http://www.spitzer.caltech.edu .

Whitney Clavin 818-354-4673

Jet Propulsion Laboratory, Pasadena, Calif.

whitney.clavin@jpl.nasa.gov


2013-289

NASA's Cassini Spacecraft Finds Ingredient of Household Plastic in Space

NASA's Cassini Spacecraft Finds Ingredient of Household Plastic in Space:

A Ring of Color
NASA's Cassini spacecraft looks toward the night side of Saturn's largest moon and sees sunlight scattering through the periphery of Titan's atmosphere and forming a ring of color. Image credit: NASA/JPL-Caltech/Space Science Institute
› Full image and caption

September 30, 2013

PASADENA, Calif. - NASA's Cassini spacecraft has detected propylene, a chemical used to make food-storage containers, car bumpers and other consumer products, on Saturn's moon Titan.


This is the first definitive detection of the plastic ingredient on any moon or planet, other than Earth.


A small amount of propylene was identified in Titan's lower atmosphere by Cassini's composite infrared spectrometer (CIRS). This instrument measures the infrared light, or heat radiation, emitted from Saturn and its moons in much the same way our hands feel the warmth of a fire.


Propylene is the first molecule to be discovered on Titan using CIRS. By isolating the same signal at various altitudes within the lower atmosphere, researchers identified the chemical with a high degree of confidence. Details are presented in a paper in the Sept. 30 edition of the Astrophysical Journal Letters.


"This chemical is all around us in everyday life, strung together in long chains to form a plastic called polypropylene," said Conor Nixon, a planetary scientist at NASA's Goddard Space Flight Center in Greenbelt, Md., and lead author of the paper. "That plastic container at the grocery store with the recycling code 5 on the bottom -- that's polypropylene."


CIRS can identify a particular gas glowing in the lower layers of the atmosphere from its unique thermal fingerprint. The challenge is to isolate this one signature from the signals of all other gases around it.


The detection of the chemical fills in a mysterious gap in Titan observations that dates back to NASA's Voyager 1 spacecraft and the first-ever close flyby of this moon in 1980.


Voyager identified many of the gases in Titan's hazy brownish atmosphere as hydrocarbons, the chemicals that primarily make up petroleum and other fossil fuels on Earth.


On Titan, hydrocarbons form after sunlight breaks apart methane, the second-most plentiful gas in that atmosphere. The newly freed fragments can link up to form chains with two, three or more carbons. The family of chemicals with two carbons includes the flammable gas ethane. Propane, a common fuel for portable stoves, belongs to the three-carbon family.


Previously, Voyager found propane, the heaviest member of the three-carbon family, and propyne, one of the lightest members. But the middle chemicals, one of which is propylene, were missing.


As researchers continued to discover more and more chemicals in Titan's atmosphere using ground- and space-based instruments, propylene was one that remained elusive. It was finally found as a result of more detailed analysis of the CIRS data.


"This measurement was very difficult to make because propylene's weak signature is crowded by related chemicals with much stronger signals," said Michael Flasar, Goddard scientist and principal investigator for CIRS. "This success boosts our confidence that we will find still more chemicals long hidden in Titan's atmosphere."


Cassini's mass spectrometer, a device that looks at the composition of Titan's atmosphere, had hinted earlier that propylene might be present in the upper atmosphere. However, a positive identification had not been made.


"I am always excited when scientists discover a molecule that has never been observed before in an atmosphere," said Scott Edgington, Cassini's deputy project scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "This new piece of the puzzle will provide an additional test of how well we understand the chemical zoo that makes up Titan's atmosphere."


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 CIRS team is based at Goddard.


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


Nancy Neal-Jones/Elizabeth Zubritsky

Goddard Space Flight Center, Greenbelt, Md.

301-286-0039/301-614-5438

nancy.n.jones@nasa.gov / elizabeth.a.zubritsky@nasa.gov


2013-295

NASA Space Telescopes Find Patchy Clouds on Exotic World

NASA Space Telescopes Find Patchy Clouds on Exotic World:

Partially Cloudy Skies on Kepler-7b
Kepler-7b (left), which is 1.5 times the radius of Jupiter (right), is the first exoplanet to have its clouds mapped. The cloud map was produced using data from NASA's Kepler and Spitzer space telescopes. Image credit: NASA/JPL-Caltech/MIT
› Full image and caption

September 30, 2013

PASADENA, Calif. -- Astronomers using data from NASA's Kepler and Spitzer space telescopes have created the first cloud map of a planet beyond our solar system, a sizzling, Jupiter-like world known as Kepler-7b.


The planet is marked by high clouds in the west and clear skies in the east. Previous studies from Spitzer have resulted in temperature maps of planets orbiting other stars, but this is the first look at cloud structures on a distant world.


"By observing this planet with Spitzer and Kepler for more than three years, we were able to produce a very low-resolution 'map' of this giant, gaseous planet," said Brice-Olivier Demory of Massachusetts Institute of Technology in Cambridge. Demory is lead author of a paper accepted for publication in the Astrophysical Journal Letters. "We wouldn't expect to see oceans or continents on this type of world, but we detected a clear, reflective signature that we interpreted as clouds."


Kepler has discovered more than 150 exoplanets, which are planets outside our solar system, and Kepler-7b was one of the first. The telescope's problematic reaction wheels prevent it from hunting planets any more, but astronomers continue to pore over almost four years' worth of collected data.


Kepler's visible-light observations of Kepler-7b's moon-like phases led to a rough map of the planet that showed a bright spot on its western hemisphere. But these data were not enough on their own to decipher whether the bright spot was coming from clouds or heat. The Spitzer Space Telescope played a crucial role in answering this question.


Like Kepler, Spitzer can fix its gaze at a star system as a planet orbits around the star, gathering clues about the planet's atmosphere. Spitzer's ability to detect infrared light means it was able to measure Kepler-7b's temperature, estimating it to be between 1,500 and 1,800 degrees Fahrenheit (1,100 and 1,300 Kelvin). This is relatively cool for a planet that orbits so close to its star -- within 0.6 astronomical units (one astronomical unit is the distance from Earth and the sun) -- and, according to astronomers, too cool to be the source of light Kepler observed. Instead, they determined, light from the planet's star is bouncing off cloud tops located on the west side of the planet.


"Kepler-7b reflects much more light than most giant planets we've found, which we attribute to clouds in the upper atmosphere," said Thomas Barclay, Kepler scientist at NASA's Ames Research Center in Moffett Field, Calif. "Unlike those on Earth, the cloud patterns on this planet do not seem to change much over time -- it has a remarkably stable climate."


The findings are an early step toward using similar techniques to study the atmospheres of planets more like Earth in composition and size.


"With Spitzer and Kepler together, we have a multi-wavelength tool for getting a good look at planets that are billions of miles away," said Paul Hertz, director of NASA's Astrophysics Division in Washington. "We're at a point now in exoplanet science where we are moving beyond just detecting exoplanets, and into the exciting science of understanding them."


Kepler identified planets by watching for dips in starlight that occur as the planets transit, or pass in front of their stars, blocking the light. This technique and other observations of Kepler-7b previously revealed that it is one of the puffiest planets known: if it could somehow be placed in a tub of water, it would float. The planet was also found to whip around its star in just less than five days.


Explore all 900-plus exoplanet discoveries with NASA's "Eyes on Exoplanets," a fully rendered 3D visualization tool, available for download at http://eyes.nasa.gov/exoplanets. The program is updated daily with the latest findings from NASA's Kepler mission and ground-based observatories around the world as they search for planets like our own.


Other authors include: Julien de Wit, Nikole Lewis, Adras Zsom and Sara Seager of Massachusetts Institute of Technology; Jonathan Fortney of the University of California, Santa Cruz; Heather Knutson and Jean-Michel Desert of the California Institute of Technology, Pasadena; Kevin Heng of the University of Bern, Switzerland; Nikku Madhusudhan of Yale University, New Haven, Conn.; Michael Gillon of the University of Liège, Belgium; Vivien Parmentier of the French National Center for Scientific Research, France; and Nicolas Cowan of Northwestern University, Evanston, Ill. Lewis is also a NASA Sagan Fellow.


The technical paper is online at http://www.mit.edu/~demory/preprints/kepler-7b_clouds.pdf .


NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA. 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 at Caltech. Caltech manages JPL for NASA. For more information about Spitzer, visit: http://spitzer.caltech.edu and http://www.nasa.gov/spitzer .


Ames is responsible for Kepler's ground system development, mission operations and science data analysis. JPL 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. For more information about the Kepler mission, visit: http://www.nasa.gov/kepler and http://www.kepler.nasa.gov .

Whitney Clavin 818-354-4673

Jet Propulsion Laboratory, Pasadena, Calif.

whitney.clavin@jpl.nasa.gov


Michele Johnson 650-604-6982

Ames Research Center, Moffett Field, Calif.

michele.johnson@nasa.gov


Steve Cole 202-358-0918

NASA Headquarters, Washington

stephen.e.cole@nasa.gov


2013-296

Rings, Dark Side of Saturn Glow in New Cassini Image

Rings, Dark Side of Saturn Glow in New Cassini Image:

This colorized mosaic from NASA's Cassini mission shows an infrared view of the Saturn system, backlit by the sun, from July 19, 2013.
This colorized mosaic from NASA's Cassini mission shows an infrared view of the Saturn system, backlit by the sun, from July 19, 2013. Image credit: NASA/JPL-Caltech/University of Arizona/Cornell
› Full image and caption

October 17, 2013

Story Highlights:


• The Cassini spacecraft scanned across Saturn and its rings when the sun was behind the planet and faint rings were easier to detect.

• This latest infrared image shows a strip about 340,000 miles (540,000 kilometers) across that includes the planet and its rings out to Saturn's second most distant ring.


PASADENA, Calif. -- The gauzy rings of Saturn and the dark side of the planet glow in newly released infrared images obtained by NASA's Cassini spacecraft.


"Looking at the Saturn system when it is backlit by the sun gives scientists a kind of inside-out view of Saturn that we don't normally see," said Matt Hedman, a participating scientist based at the University of Idaho, Moscow, Idaho. "The parts of Saturn's rings that are bright when you look at them from backyard telescopes on Earth are dark, and other parts that are typically dark glow brightly in this view."


The images are available at: http://www.jpl.nasa.gov/spaceimages/details.php?id=pia17468 and
http://www.jpl.nasa.gov/spaceimages/details.php?id=pia17469 .


It can be difficult for scientists to get a good look at the faint outer F, E and G rings, or the tenuous inner ring known as the D ring when light is shining directly on them. That's because they are almost transparent and composed of small particles that do not reflect light well. What's different about this viewing geometry?


• When these small particles are lit from behind, they show up like fog in the headlights of an oncoming vehicle.

• The C ring also appears relatively bright here; not because it is made of dust, but because the material in it -- mostly dirty water ice -- is translucent. In fact, in the 18th and 19th centuries, it was known as the "crepe ring" because of its supposed similarity to crepe paper.

• The wide, middle ring known as the B ring -- one of the easiest to see from Earth through telescopes because it is densely packed with chunks of bright water ice -- looks dark in these images because it is so thick that it blocks almost all of the sunlight shining behind it.


Infrared images also show thermal, or heat, radiation. While a visible-light image from this vantage point would simply show the face of the planet as dimly lit by sunlight reflected off the rings, Saturn glows brightly in this view because of heat from Saturn's interior.


In a second version of the image, scientists "stretched" or exaggerated the contrast of the data, which brings out subtleties not initially visible.


• Structures in the wispy E ring -- made from the icy breath of the moon Enceladus -- reveal themselves in this exaggerated view.


"We're busy working on analyzing the infrared data from this special view of the Saturn system," said Phil Nicholson, a visual and infrared mapping spectrometer team member from Cornell University, Ithaca, N.Y. "The infrared data should tell us more about the sizes of the particles which make up the D, E, F and G rings, and how these sizes vary with location in the rings, as well as providing clues as to their chemical composition."


Launched in 1997, Cassini has been exploring the Saturn system for more than nine years with a suite of instruments that also includes visible-light cameras, ultraviolet and infrared spectrometers, as well as magnetic field and charged particle sensors. Scientists working with the visible light cameras are still busy putting together and analyzing their mosaic -- or multi-image picture -- of the Saturn system.


"Cassini's long-term residency at the ringed planet means we've been able to observe change over nearly half a Saturn-year (one Saturn-year is equal to almost 30 Earth-years) with a host of different tools," said Linda Spilker, Cassini project scientist, based at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "Earth looks different from season to season and Saturn does, too. We can't wait to see how those seasonal changes affect the dance of icy particles as we continue to observe in Saturn's rings with all of Cassini's different 'eyes.'"


The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL manages the mission for NASA's Science Mission Directorate, Washington. The California Institute of Technology in Pasadena manages JPL for NASA. 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 Cook 818-354-0850

Jet Propulsion Laboratory, Pasadena, Calif.

jccook@jpl.nasa.gov


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