cassini division

What’s Up for June 2017?

Have a planet party and compare Saturn and Jupiter! We’ll show you where and when to point your telescope or binoculars to see these planets and their largest moons. 

Meet at midnight to have a planetary party when Jupiter and Saturn are visible at the same time!

The best time will be after midnight on June 17. To see the best details, you’ll need a telescope.

Saturn will be at opposition on June 15, when Saturn, the Earth and the sun are in a straight line.

Opposition provides the best views of Saturn and several of its brightest moons. At the very least, you should be able to see Saturn’s moon Titan, which is larger and brighter than Earth’s moon.

As mentioned earlier, you’ll be able to see Jupiter and Saturn in the night sky this month. Through a telescope, you’ll be able to see the cloud bands on both planets. Saturn’s cloud bands are fainter than those on Jupiter. 

You’ll also have a great view of Saturn’s Cassini Division, discovered by astronomer Giovanni Cassini in 1675, namesake of our Cassini spacecraft.

Our Cassini spacecraft has been orbiting the planet since 2004 and is on a trajectory that will ultimately plunge it into Saturn’s atmosphere on September 15, 2017, bringing the mission to a close. 

Our Juno spacecraft recently completed its sixth Jupiter flyby. Using only binoculars you can observe Jupiter’s 4 Galilean moons - Io, Callisto, Ganymede and Europa.

To learn about What’s Up in the skies for June 2017, watch the full video:

For more astronomy events, check out NASA’s Night Sky Network at https://nightsky.jpl.nasa.gov/.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

Saturn near Opposition : Saturn reached its 2017 opposition on June 16. Of course, opposition means opposite the Sun in Earth’s sky and near opposition Saturn is up all night, at its closest and brightest for the year. This remarkably sharp image of the ringed planet was taken only days before, on June 11, with a 1-meter telescope from the mountain top Pic du Midi observatory. North is at the top with the giant planet’s north polar storm and curious hexagon clearly seen bathed in sunlight. But Saturn’s spectacular ring system is also shown in stunning detail. The narrow Encke division is visible around the entire outer A ring, small ringlets can be traced within the fainter inner C ring, and Saturn’s southern hemisphere can be glimpsed through the wider Cassini division. Near opposition Saturn’s rings also appear exceptionally bright, known as the opposition surge or Seeliger Effect. Directly illuminated from Earth’s perspective, the ring’s icy particles cast no shadows and strongly backscatter sunlight creating the dramatic increase in brightness. Still, the best views of the ringed planet are currently from the Saturn-orbiting Cassini spacecraft. Diving close, Cassini’s Grand Finale orbit number 9 is in progress. via NASA

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Saturn reached its 2017 opposition on June 16. Of course, opposition means opposite the Sun in Earth’s sky and near opposition Saturn is up all night, at its closest and brightest for the year. This remarkably sharp image of the ringed planet was taken only days before, on June 11, with a 1-meter telescope from the mountain top Pic du Midi observatory. North is at the top with the giant planet’s north polar storm and curious hexagon clearly seen bathed in sunlight. But Saturn’s spectacular ring system is also shown in stunning detail. The narrow Encke division is visible around the entire outer A ring, small ringlets can be traced within the fainter inner C ring, and Saturn’s southern hemisphere can be glimpsed through the wider Cassini division. Near opposition Saturn’s rings also appear exceptionally bright, known as the opposition surge or Seeliger Effect. Directly illuminated from Earth’s perspective, the ring’s icy particles cast no shadows and strongly backscatter sunlight creating the dramatic increase in brightness. Still, the best views of the ringed planet are currently from the Saturn-orbiting Cassini spacecraft. Diving close, Cassini’s Grand Finale orbit number 9 is in progress.

Image Credit & Copyright: D. Peach, E. Kraaikamp, F. Colas, M. Delcroix, R. Hueso, G. Therin, C. Sprianu, S2P, IMCCE, OMP

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Cassini’s ‘Inside-Out’ Rings Movie

This movie sequence of images from NASA’s Cassini spacecraft offers a unique perspective on Saturn’s ring system. Cassini captured the images from within the gap between the planet and its rings, looking outward as the spacecraft made one of its final dives through the gap as part of the mission’s Grand Finale.

Using its wide-angle camera, Cassini took the 21 images in the sequence over a span of about four minutes during its dive through the gap on Aug. 20, 2017. The images have an original size of 512 x 512 pixels; the smaller image size allowed for more images to be taken over the short span of time.

The entirety of the main rings can be seen here, but due to the low viewing angle, the rings appear extremely foreshortened. The perspective shifts from the sunlit side of the rings to the unlit side, where sunlight filters through. On the sunlit side, the grayish C ring looks larger in the foreground because it is closer; beyond it is the bright B ring and slightly less-bright A ring, with the Cassini Division between them. The F ring is also fairly easy to make out.

Ring Scan 

Scroll down and you can cruise along the icy rings of Saturn. This high resolution scan is a mosaic of images presented in natural color. The images were recorded in May 2007 over about 2.5 hours as the Cassini spacecraft passed above the unlit side of the rings. To help track your progress, major rings and gaps are labeled along with the distance from the center of the gas giant in kilometers.

The alphabetical designation of Saturn’s rings is historically based on their order of discovery; rings A and B are the bright rings separated by the Cassini division. In order of increasing distance from Saturn, the seven main rings run D,C,B,A,F,G,E. (Faint, outer rings G and E are not imaged here.) Four days from now, on November 29, Cassini will make a close flyby of Saturn’s moon Titan and use the large moon’s gravity to nudge the spacecraft into a series of 20 daring, elliptical, ring-grazing orbits. Diving through the ring plane just 11,000 kilometers outside the F ring (image bottom) Cassini’s first ring-graze will be on December 4.

What’s more majestic than Saturn’s rings? LITERALLY NOTHING!!

Zoom in on this awesome high resolution scan of Saturn’s rings. It’s a mosaic of images presented in natural color. The images were recorded in May 2007 over about 2.5 hours as the Cassini spacecraft passed above the unlit side of the rings.

The alphabetical designation of Saturn’s rings is historically based on their order of discovery; rings A and B are the bright rings separated by the Cassini division. In order of increasing distance from Saturn, the seven main rings run D,C,B,A,F,G,E. (Faint, outer rings G and E are not seen in this image.)

FOUR days from now, on November 29, Cassini will make a close flyby of Saturn’s moon Titan and use the large moon’s gravity to nudge the spacecraft into a series of 20 daring, elliptical, ring-grazing orbits. Diving through the ring plane just 11,000 kilometers outside the F ring (far right) Cassini’s first ring-graze will be on December 4.

Image Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA

Jet Propulsion Laboratory (JPL) workers examine the Huygens probe after removal from the Cassini spacecraft in the Payload Hazardous Servicing Facility (PHSF) at KSC. The spacecraft was returned to the PHSF after damage to the thermal insulation was discovered inside Huygens from an abnormally high flow of conditioned air. The damage required technicians to inspect the inside of the probe, repair the insulation, and clean the instruments.

After returning from the PHSF to Launch Pad 40 at Cape Canaveral Air Station, Cassini/Huygens launched successfully in October 1997, and reached Saturn in July of 2004. Scientific instruments carried aboard the Cassini orbiter studied Saturn’s atmosphere, magnetic field, rings, and several moons, while the Huygens probe separated and landed on the surface of Titan, Saturn’s largest moon.

The Cassini-Huygens mission owes its name to the Dutch astronomer Christiaan Huygens and Italian astronomer Giovanni Domenico Cassini. Both had spectacular careers as observers of the heavens, which included important discoveries about Saturn and its satellites. Huygens (1629-1695) discovered Saturn’s largest moon, Titan, in 1655 and in 1656 described the shape and phase changes of Saturn’s rings. Cassini (1625-1712) was the first to observe four of Saturn’s moons, Iapetus, Rhea, Tethys, and Dione, in the 1670s and 1680s. He also, in 1675, discovered the gap in Saturn’s rings, now called the Cassini Division, and proposed that the rings were formed from many tiny particles.

Cassini-Huygens is a joint mission of NASA, the European Space Agency (ESA), and the Italian Space Agency, Agenzia Spaziale Italiana (ASI).

What’s Up for June 2016?

What’s Up for June? Saturn at its best! Plus, good views of Mars, Jupiter and Jupiter’s moons continue from dusk to dawn.

You don’t have to stay up late to see Jupiter, Mars and Saturn this month, because they’re all visible soon after sunset. Jupiter is the brightest of the three, visible in the western sky all evening. 

The four Galilean moons are easily visible in binoculars or telescopes. If you think you’re seeing 5 moons on June 10th, you’re not. One of them is a distant star in the constellation Leo.

For telescope viewers, the time near Mars’ closest approach to Earth, May 30th this year, is the best time to try to see the two moons of Mars: Phobos and Deimos. It takes patience, very steady skies and good charts! Mars is still large and bright in early June, but it fades as speedy Earth, in its shorter orbit around the sun, passes it.

Saturn has been close to Mars recently. This month Saturn reaches opposition, when Saturn, Earth and the sun are in a straight line with Earth in the middle, providing the best and closest views of the ringed beauty and several of its moons. You’ll be able to make out cloud bands on Saturn, in delicate shades of cream and butterscotch. They’re fainter than the bands of Jupiter. Through a telescope you’ll see Saturn’s rings tilted about as wide as they get: 26 degrees.

You’ll also have a ring-side view of the Cassini division, discovered by Giovanni Domenico Cassini, namesake of our Cassini spacecraft, orbiting Saturn since 2004 and continuing through September 2017. When you look at Saturn through a telescope, you can’t help but see several of its 4 brightest moons, and maybe more. If you just see one, that’s Titan, 50% larger than our own moon. A telescope can also reveal more moons, like Saturn’s two-colored moon Iapetus. It takes 3 months to orbit Saturn, and it’s fairly easy to see.

There’s a bright comet visible this month, Comet PanSTARRS. It’s best seen from the southern hemisphere, but it’s also visible from the U.S. low in the morning sky. Comet PanSTARRS can be seen through a telescope near the beautiful Helix Nebula on June 4, but it is visible all month.

Watch the full June “What’s Up” video for more: https://youtu.be/M7RtIa9zBYA

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

Saturn’s glorious rings up close.

Space.com: “From the inside out, the "Cassini division” in faint red at left is followed by the A ring in its entirety in this ultraviolet-light image. The A ring begins with a “dirty” interior of red followed by more blue as it spreads away from the planet. The blue is a signature of water ice. The red band roughly three-fourths of the way outward in the A ring is known as the Encke gap.“

Credit: NASA/JPL

Ring Structure Discovered

This picture is a close-up of a section of vertical structures within Saturn’s main rings. The structures pictured are some of the tallest ever seen and cast long shadows as they rise sharply from the edge of the B ring. Taken just before the August equinox in 2009, the pictures shows the Cassini division (top of the image), which is the space between the A ring and the B ring.

The section in this photo shows a 750 mile long (1,200 km) section with the vertical structures spanning a whopping 1.6 miles (2.5 km) above the plane of the rings. This is quite different from the main A, B, and C rings as they typically span 30 feet (10 meters) across.

Cassini scientists hypothesize that large bodies, such as moonlets, up to one kilometer or more in size can be found. These large bodies can have an impact on the ring material around them, forcing particles upwards and potentially causing these structures. 

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Image & Source Credit: NASA/JPL/SSI

Saturn’s Rings and Shadow

Saturn’s rings cast shadows on the planet, except their shadows appear to be inside out! The edge of the outermost A ring can be seen at the top left corner of the image. Moving towards the bottom of the page, one can see the faint Cassini Division, the opaque B ring and the innermost C ring, which contains several ringlets that appear dark against Saturn in this geometry. The bottom half of the image features the shadows of these rings in reverse order superposed against the disk of the planet: the C ring, the B ring, the Cassini Division and the inner half of the A ring.

This view looks toward the unilluminated side of the rings from about 28 degrees below the ringplane. The image was taken with the Cassini spacecraft wide-angle camera on Dec. 2, 2013 using a spectral filter which preferentially admits wavelengths of near-infrared light centered at 752 nanometers. The view was acquired at a distance of approximately 750,000 miles (1.2 million kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 57 degrees. Image scale is 45 miles (72 kilometers) per pixel.

Image Credit: NASA/JPL-Caltech/Space Science Institute

Environmental Health Specialist Jamie A. Keeley of EG&G Florida Inc., KSC’s base operations contractor, uses an ion chamber dose rate meter to measure radiation levels in one of the three radioisotope thermoelectric generators (RTGs) that will provide electrical power to the Cassini spacecraft. Technicians tested and monitored four RTGs, including one spare, in the Radioisotope Thermoelectric Generator Storage building in KSC’s Industrial Area. The RTGs use heat from the natural decay of plutonium to generate electric power. This nuclear powered system enables the spacecraft to operate far from the Sun, where solar power systems are not feasible. Similar RTGs powered the Galileo and Ulysses spacecraft.

A close-up study of Saturn and its moons, the Cassini/Huygens mission launched from Cape Canaveral Air Station in October 1997 and reached the Saturnian system in July 2004 for four years of observation. Scientific instruments carried aboard the Cassini orbiter will study Saturn’s atmosphere, magnetic field, rings, and several moons, while the Huygens probe will separate and land on the surface of Titan, Saturn’s largest moon.

The Cassini-Huygens mission owes its name to the Dutch astronomer Christiaan Huygens and Italian astronomer Giovanni Domenico Cassini. Both had spectacular careers as observers of the heavens, which included important discoveries about Saturn and its satellites. Huygens (1629-1695) discovered Saturn’s largest moon, Titan, in 1655 and in 1656 described the shape and phase changes of Saturn’s rings. Cassini (1625-1712) was the first to observe four of Saturn’s moons, Iapetus, Rhea, Tethys, and Dione, in the 1670s and 1680s. He also, in 1675, discovered the gap in Saturn’s rings, now called the Cassini Division, and proposed that the rings were formed from many tiny particles.

Cassini-Huygens is a joint mission of NASA, the European Space Agency (ESA), and the Italian Space Agency, Agenzia Spaziale Italiana (ASI). JPL is managing the Cassini project for NASA. The mission was proposed in November 1982 by a group of European and American scientists from the European Science Foundation and the National Academy of Sciences. The Solar System Exploration Committee of the NASA Advisory Council endorsed the idea in April 1983, and NASA and ESA began a joint assessment study in 1984. ESA officially adopted the project in November 1988, and Congress approved funding for NASA’s portion of the mission in FY 89.