Posing for portraits for NASA’s Cassini spacecraft, Saturn and its largest moon, Titan, show spectacular colors in a quartet of images being released today. One image captures the changing hues of Saturn’s northern and southern hemispheres as they pass from one season to the next.

A wide-angle view in today’s package captures Titan passing in front of
Saturn, as well as the planet’s changing colors. Upon Cassini’s arrival
at Saturn eight years ago, Saturn’s northern winter hemisphere was an
azure blue. 

Now that winter is encroaching on the planet’s southern
hemisphere and summer on the north, the color scheme is reversing:  blue
is tinting the southern atmosphere and is fading from the north. 

The images can be found at http://www.nasa.gov/cassini, http://saturn.jpl.nasa.gov and http://ciclops.org.

The other three images depict the newly discovered south polar vortex in the atmosphere of Titan, reported recently by Cassini scientists. Cassini’s visible-light cameras have seen a concentration of yellowish haze in the detached haze layer at the south pole of Titan since at least March 27. Cassini’s visual and infrared mapping spectrometer spotted the massing of clouds around the south pole as early as May 22 in infrared wavelengths. After a June 27 flyby of the moon, Cassini released a dramatic image and movie showing the vortex rotating faster than the moon’s rotation period. The four images being released today were acquired in May, June and July of 2012.

Some of these views, such as those of the polar vortex, are only possible because Cassini’s newly inclined — or tilted — orbits allow more direct viewing of the polar regions of Saturn and its moons.    

Scientists are looking forward to seeing more of the same — new phenomena like Titan’s  south polar vortex and changes wrought by the passage of time and seasons  — during the remainder of Cassini’s mission.

“Cassini has been in orbit now for the last eight years, and despite the fact that we can’t know exactly what the next five years will show us, we can be certain that whatever it is will be wondrous," said Carolyn Porco, imaging team lead based at the Space Science Institute in Boulder, Colo.
 
Launched in 1997, Cassini went into orbit around Saturn on July 1, 2004. It is in its second mission extension, known as the Solstice Mission, and one of its main goals is to analyze seasonal changes in the Saturn system.

"It is so fantastic to experience, through the instruments of Cassini, seasonal changes in the Saturn system," said Amanda Hendrix, deputy project scientist, based at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. "Some of the changes we see in the data are completely unexpected, while some occur like clockwork on a seasonal timescale. It’s an exciting time to be at Saturn."

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 in Pasadena, manages the Cassini-Huygens mission for NASA’s Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute in Boulder, Colo. 

Updated:  NASA’s most advanced Mars rover Curiosity has landed on the Red Planet. The one-ton rover, hanging by ropes from a rocket backpack, touched down onto Mars Sunday to end a 36-week flight and begin a two-year investigation.

The Mars Science Laboratory (MSL) spacecraft that carried Curiosity succeeded in every step of the most complex landing ever attempted on Mars, including the final severing of the bridle cords and flyaway maneuver of the rocket backpack.

"Today, the wheels of Curiosity have begun to blaze the trail for human footprints on Mars.  Curiosity, the most sophisticated rover ever built, is now on the surface of the Red Planet, where it will seek to answer age-old questions about whether life ever existed on Mars — or if the planet can sustain life in the future," said NASA Administrator Charles Bolden. "This is an amazing achievement, made possible by a team of scientists and engineers from around the world and led by the extraordinary men and women of NASA and our Jet Propulsion Laboratory. President Obama has laid out a bold vision for sending humans to Mars in the mid-2030’s, and today’s landing marks a significant step toward achieving this goal."  

Curiosity landed at 10:32 p.m. Aug. 5, PDT, (1:32 a.m. EDT Aug. 6) near the foot of a mountain three miles tall and 96 miles in diameter inside Gale Crater. During a nearly two-year prime mission, the rover will investigate whether the region ever offered conditions favorable for microbial life.

"The Seven Minutes of Terror has turned into the Seven Minutes of Triumph," said NASA Associate Administrator for Science John Grunsfeld. "My immense joy in the success of this mission is matched only by overwhelming pride I feel for the women and men of the mission’s team.”

Curiosity returned its first view of Mars, a wide-angle scene of rocky ground near the front of the rover. More images are anticipated in the next several days as the mission blends observations of the landing site with activities to configure the rover for work and check the performance of its instruments and mechanisms.

"Our Curiosity is talking to us from the surface of Mars," said MSL Project Manager Peter Theisinger of NASA’s Jet Propulsion Laboratory in Pasadena, Calif. "The landing takes us past the most hazardous moments for this project, and begins a new and exciting mission to pursue its scientific objectives."

Confirmation of Curiosity’s successful landing came in communications relayed by NASA’s Mars Odyssey orbiter and received by the Canberra, Australia, antenna station of NASA’s Deep Space Network.

Curiosity carries 10 science instruments with a total mass 15 times as large as the science payloads on the Mars rovers Spirit and Opportunity. Some of the tools are the first of their kind on Mars, such as a laser-firing instrument for checking elemental composition of rocks from a distance. The rover will use a drill and scoop at the end of its robotic arm to gather soil and powdered samples of rock interiors, then sieve and parcel out these samples into analytical laboratory instruments inside the rover.

To handle this science toolkit, Curiosity is twice as long and five times as heavy as Spirit or Opportunity. The Gale Crater landing site places the rover within driving distance of layers of the crater’s interior mountain. Observations from orbit have identified clay and sulfate minerals in the lower layers, indicating a wet history.

The mission is managed by JPL for NASA’s Science Mission Directorate in Washington. The rover was designed, developed and assembled at JPL. JPL is a division of the California Institute of Technology in Pasadena.

For more information on the mission, click here or here.  Follow the mission on Facebook click here and Twitter click here.

NASA Photos and Illustrations

1.) NASA control staff cheer landing.

2.) Curiosity’s Surroundings – Taken through a "fisheye" wide-angle lens on the left "eye" of a stereo pair of Hazard-Avoidance cameras on the left-rear side of the rover. The image is one-half of full resolution. The clear dust cover that protected the camera during landing has been sprung open. Part of the spring that released the dust cover can be seen at the bottom right, near the rover’s wheel. On the top left, part of the rover’s power supply is visible. Some dust appears on the lens even with the dust cover off.

The cameras are looking directly into the sun, so the top of the image is saturated. Looking straight into the sun does not harm the cameras. The lines across the top are an artifact called "blooming" that occurs in the camera’s detector because of the saturation.

As planned, the rover’s early engineering images are lower resolution. Larger color images from other cameras are expected later in the week when the rover’s mast, carrying high-resolution cameras, is deployed. Image credit: NASA/JPL-Caltech

3.) NASA’s $2.5 billion Mars Science Laboratory (MSL) Curiosity will use 10 instruments to probe areas of Mars and determine whether conditions – and chemical ingredients – are favorable for life. Its mission is expected to last two years.

4.) An image from the High Resolution Imaging Science Experiment (HiRISE) camera aboard NASA’s Mars Reconnaissance orbiter captured the Curiosity rover still connected to its 51-foot-wide (almost 16 meter) parachute as it descended towards its landing site at Gale Crater.

"If HiRISE took the image one second before or one second after, we probably would be looking at an empty Martian landscape," said Sarah Milkovich, HiRISE investigation scientist at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. "When you consider that we have been working on this sequence since March and had to upload commands to the spacecraft about 72 hours prior to the image being taken, you begin to realize how challenging this picture was to obtain."

NASA’s Dawn spacecraft has provided researchers with the first orbital analysis of the giant asteroid Vesta, yielding new insights into its creation and kinship with terrestrial planets and Earth’s moon.

Vesta now has been revealed as a special fossil of the early solar system with a more varied, diverse surface than originally thought. Scientists have confirmed a variety of ways in which Vesta more closely resembles a small planet or Earth’s moon than another asteroid. Results appear in today’s edition of the journal Science.

"Dawn’s visit to Vesta has confirmed our broad theories of this giant asteroid’s history, while helping to fill in details it would have been impossible to know from afar," said Carol Raymond, deputy principal investigator at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. "Dawn’s residence at Vesta of nearly a year has made the asteroid’s planet-like qualities obvious and shown us our connection to that bright orb in our night sky."

Scientists now see Vesta as a layered, planetary building block with an iron core – the only one known to survive the earliest days of the solar system. The asteroid’s geologic complexity can be attributed to a process that separated the asteroid into a crust, mantle and iron core with a radius of approximately 68 miles (110 kilometers) about 4.56 billion years ago. The terrestrial planets and
Earth’s moon formed in a similar way.

Dawn observed a pattern of minerals exposed by deep gashes created by space rock impacts, which may support the idea the asteroid once had a subsurface magma ocean. A magma ocean occurs when a body undergoes almost complete melting, leading to layered building blocks that can form planets. Other bodies with magma oceans ended up becoming parts of Earth and other planets.

Data also confirm a distinct group of meteorites found on Earth did, as theorized, originate from Vesta. The signatures of pyroxene, an iron- and magnesium-rich mineral, in those meteorites match those of rocks on Vesta’s surface. These objects account for about 6 percent of all meteorites seen falling on Earth.

This makes the asteroid one of the largest single sources for Earth’s meteorites. The finding also marks the first time a spacecraft has been able to visit the source of samples after they were identified on Earth.

Scientists now know Vesta’s topography is quite steep and varied. Some craters on Vesta formed on very steep slopes and have nearly vertical sides, with landslides occurring more frequently than expected.

Another unexpected finding was that the asteroid’s central peak in the Rheasilvia basin in the southern hemisphere is much higher and wider, relative to its crater size, than the central peaks of craters on bodies like our moon. Vesta also bears similarities to other low-gravity worlds like Saturn’s small icy moons, and its surface has light and dark markings that don’t match the predictable
patterns on Earth’s moon.

"We know a lot about the moon and we’re only coming up to speed now on Vesta," said Vishnu Reddy, a framing camera team member at the Max Planck Institute for Solar System Research in Germany and the University of North Dakota in Grand Forks. "Comparing the two gives us two story lines for how these fraternal twins evolved in the early solar system."

Dawn has revealed details of ongoing collisions that battered Vesta throughout its history. Dawn scientists now can date the two giant impacts that pounded Vesta’s southern hemisphere and created the basin Veneneia approximately 2 billion years ago and the Rheasilvia basin about 1 billion years ago. Rheasilvia is the largest impact basin on Vesta.

"The large impact basins on the moon are all quite old," said David O’Brien, a Dawn participating scientist from the Planetary Science Institute in Tucson, Ariz. "The fact that the largest impact on Vesta is so young was surprising."

Launched in 2007, Dawn began exploring Vesta in mid-2011. The spacecraft will depart Vesta on August 26 for its next study target, the dwarf planet Ceres, in 2015.

Dawn’s mission to Vesta and Ceres is managed by JPL for NASA’s Science Mission Directorate in Washington. Dawn is a project of the directorate’s Discovery Program managed by NASA’s Marshall Space Flight Center in Huntsville, Ala. UCLA is responsible for overall Dawn mission science. Orbital Sciences Corp. in Dulles, Va., designed and built the spacecraft. The German Aerospace Center, the Max Planck Institute for Solar System Research, the Italian Space Agency and the Italian National Astrophysical Institute are international partners on the mission team. The California Institute of Technology in Pasadena manages JPL for NASA.

For images and videos related to the findings, click here.

For more information about the Dawn mission, click here or here.

Now is the time to start searching for the scissor-tailed flycatcher on its way north from the tropics to spend the summer in Oklahoma. Oklahoma is one of only seven United States in which the bird nests.

"Scissortails are neo-tropical migrants, which breed in North America in
the summer and winter in Central and South America or the Caribbean
islands," said Rachel Bradley, wildlife diversity information specialist
for the Oklahoma Department of Wildlife Conservation. "People will
begin seeing them in Oklahoma any day now and they’ll inhabit the state
until late October."

The birds are easily identified by their long, scissor-like tail that is seen outstretched during flight. Scissortails can often be seen perching on fences and telephone wires along open prairie roadsides watching for food.

According to Bradley, the scissortail’s diet consists largely of insects.

Landowners may make their land more attractive to scissor-tailed flycatchers and certain other bird species by planting and maintaining scattered shade and shrubs to add perching and nesting sites.

Wildlife enthusiasts who are not landowners can still benefit scissortails and other wildlife by supporting the Department’s Wildlife Diversity Program, which is committed to species not hunted or fished. They can aid the Wildlife Diversity Program by purchasing a Wildlife Conservation license plate, a Wildlife Department publication or by donating directly to the Wildlife Diversity fund. For more information about the Wildlife Diversity Program, log on to wildlifedepartment.com. 

In a BBC Science story, Jonathan Amos reports on findings that suggest spacecraft could one day navigate through the cosmos using a particular type of dead star (pulsars) as a kind of GPS.

German scientists are developing a technique that allows for very precise positioning anywhere in space by picking up X-ray signals from pulsars.

These dense, burnt-out stars rotate rapidly, sweeping their emission across the cosmos at rates that are so stable they rival atomic clock performance.

This timing property is perfect for interstellar navigation, says the team.

If a spacecraft carried the means to detect the pulses, it could compare their arrival times with those predicted at a reference location. This would enable the craft to determine its position to an accuracy of just five kilometres anywhere in the galaxy.

"The principle is so simple that it will definitely have applications," said Prof Werner Becker from the Max-Planck Institute for Extraterrestrial Physics in Garching.

"These pulsars are everywhere in the Universe and their flashing is so predictable that it makes such an approach really straightforward," he told BBC News.

Prof Becker has been describing his team’s research here at the UK National Astronomy Meeting in Manchester.

Click here to read more from the BBC.