As NASA’sCassini spacecraft made its first-ever dive through the gap between Saturn and its rings on April 26, 2017, one of its imaging cameras took a series of rapid-fire images that were used to make this movie sequence. The video begins with a view of the vortex at Saturn’s north pole, then heads past the outer boundary of the planet’s hexagon-shaped jet stream and continues further southward.
A detailed caption describing these video clips, and the unedited clips themselves, are available here. For more information about Cassini‘s Grand Finale, visit here.
The first Cassini to explore Saturn was a person. Space probe preparing to crash into ringed planet was named for an astronomical pioneer, by Tom Siegfried, 7:00am, May 15, 2017: here.
50 years ago, an Earth-based telescope spotted Saturn’s fourth ring: here.
Closest Saturn Pics Yet Snapped During Daring Cassini Dive
27 April 2017
NASA’s Cassini spacecraft’s ’Grand Finale’ has begun with the first of 22 planned dives between Saturn‘s innermost rings and the planet itself. The probe came within about 1900 miles (3000 km) of the planet’s cloudtops and captured some amazing images.
The first closeup pictures of the planet’s atmosphere reveal peculiar threadlike clouds and puffy cumulus ones, plus the giant hurricane first spotted on Saturn in 2008 (SN: 11/8/08, p. 9). Released April 27, the images of Saturn’s cloud tops are a “big step forward” for understanding the planet’s atmosphere, says Cassini imaging team member Andy Ingersoll, an atmospheric scientist at Caltech.
“I was pretty struck by the prevalence of the filamentary type of clouds,” he says. “It’s as if the long threads of clouds refuse to mix with each other.” Studying the interactions of these clouds and the cumulus ones will reveal what’s going on in Saturn’s skies.
During its dive, Cassini swooped to within 3,000 kilometers of the planet’s atmosphere and 300 kilometers of the innermost edge of the rings at 124,000 kilometers per hour. Slamming into even tiny particles from the rings could have damaged the spacecraft. To protect Cassini, mission scientists used the spacecraft’s 4-meter-wide antenna as a shield, putting the spacecraft temporarily out of contact with NASA.
Cassini reestablished contact with mission control early on April 27 and started to send back data minutes later. Shots of the rings and other features will be available in the coming days, and more stunning views are expected when the spacecraft shoots through the gap between Saturn and its rings again on May 2. It will ultimately orbit 20 more times before plunging into the planet’s atmosphere on September 15 (SN Online: 4/21/17).
In Cassini‘s last act, the spacecraft will whiz 22 times between Saturn and its rings. This animation illustrates the spacecraft’s final orbits. Read more here.
Other ocean-harboring moons, such as Jupiter’s Europa and Saturn’s Enceladus, are crisscrossed by fractures opened by strong tides that cause their oceans to bulge outward. Mimas, though freckled with craters, lacks any such cracks.
Planetary scientist Alyssa Rhoden of Arizona State University in Tempe and colleagues calculated whether Mimas’ icy shell could withstand the stress of a subsurface ocean pushing outward. Taking into account the moon’s elongated orbit, the researchers estimate that a subsurface ocean would produce tidal stresses larger than those on crack-riddled Europa. Mimas therefore probably doesn’t have an ocean, the researchers conclude February 24 in the Journal of Geophysical Research: Planets.
In new Cassini portraits, Saturn’s moon Pan looks like pasta, by Helen Thompson, 5:30pm, March 10, 2017: here.
At just 240,000 miles from Saturn‘s north pole, NASA’s Cassini spacecraft snapped some stunning photos. These are the first images of the spacecraft’s new mission, which is taking it closer to Saturn than it has been since it arrived at Saturn in 2004.
NASA’s Cassini takes breathtaking images of Saturn’s northern hemisphere
NASA’s Cassini has been soaring through the cosmos for nearly 20 years and to celebrate the latest phase of its journey, the intrepid spacecraft has sent scientists new images of Saturn’s northern hemisphere.
The purpose of Cassini’s newest mission phase, called Ring-Grazing Orbits, is to skim past the outer edges of the planet’s main rings, according to NASA. The pictures … which highlight the planet’s hexagon-shaped jet stream, were taken in early December.
Cassini will continue its ring-grazing orbits until April 22 of next year, where it will then begin its descent toward the planet’s surface. By September of 2017, Cassini will no longer exist.
The beginning of the end
Cassini launched all the way back in 1997 and has continued to study the Saturn system since arriving in 2004.
Over the years, the orbiter has uncovered a potential ocean on a Saturn moon, and sent back an incredibly beautiful image of a hurricane on the planet, among many other accomplishments.
Saturn’s 10th moon was the first satellite discovered in the modern space age. Excerpt from the January 14, 1967, issue of Science News: here.
NASA found the “Death Star” — or at least a moon of Saturn that looks just like it: here.
Thirteen hours of radio emissions from Jupiter’s intense auroras are presented here, both visually and in sound. The data was collected when the spacecraft made its first orbital pass of the gas giant on Aug 27, 2016, with all spacecraft instruments turned on. The frequency range of these signals is from 7 to 140 kilohertz. Radio astronomers call these “kilometric emissions” because their wavelengths are about a kilometer long.
The full story and more images from Juno‘s first pass of Jupiter with all instruments on is here.
Juno spacecraft goes into ‘safe mode’, continues to orbit Jupiter
by Christopher Crockett
6:57pm, October 19, 2016
PASADENA, Calif. — NASA’s Juno spacecraft, in orbit around Jupiter since July 4, is lying low after entering an unexpected “safe mode” early on October 19. A misbehaving valve in the fuel system, not necessarily related to the safe mode, has also led to a delay in a planned engine burn that would have shortened the probe’s orbit.
Juno turned off its science instruments and some other nonessential components this morning at 1:47 a.m. EDT after computers detected some unexpected situation, mission head Scott Bolton reported at an October 19 news conference. The spacecraft was hurtling toward its second close approach to the planet, soaring about 5,000 kilometers from the cloud tops. It has now passed that point and is moving back away from the planet with all science instruments switched off.
The rocket firing was intended to take Juno from a 53.5-day orbit to a 14-day orbit. Juno can stay in its current orbit indefinitely without any impact on the science goals, Bolton said. The goal of the mission — to peer deep beneath Jupiter’s clouds — depends on the close approaches that it makes with every orbit, not how quickly it loops around. “We changed to a 14-day orbit primarily because we wanted the science faster,” he said. “But there’s no requirement to do that.”
For now, mission scientists are trying to figure what happened with the fuel valve and what triggered the safe mode before proceeding with further instructions to the probe.
First peek under clouds reveals Jupiter’s surprising depths. Colorful bands stretch hundreds of kilometers inward, Juno spacecraft data show. By Christopher Crockett, 9:00am, October 21, 2016: here.
Essential data from the ExoMars Schiaparelli lander sent to its mothership Trace Gas Orbiter during the module’s descent to the Red Planet’s surface yesterday has been downlinked to Earth and is currently being analysed by experts.
Early indications from both the radio signals captured by the Giant Metrewave Radio Telescope (GMRT), an experimental telescope array located near Pune, India, and from orbit by ESA’s Mars Express, suggested the module had successfully completed most steps of its 6-minute descent through the martian atmosphere. This included the deceleration through the atmosphere, and the parachute and heat shield deployment, for example.
But the signals recorded by both Pune and Mars Express stopped shortly before the module was expected to touchdown on the surface. Discrepancies between the two data sets are being analysed by experts at ESA’s space operations centre in Darmstadt, Germany.
ExoMars mission has both success and failure: here.
First signs of boron on Mars hint at past groundwater, habitability: here.
Red Planet’s interior may not churn much. Composition of 2.4-billion-year-old Martian meteorite matches that of younger ones. By Thomas Sumner
2:00pm, February 1, 2017: here.
Experts don’t agree on age of Saturn’s rings. Data from orbiting Cassini craft may help resolve debate. By Christopher Crockett, 8:53am, October 20, 2016: here.
Possibly cloudy forecast for parts of Pluto. Bright patches in New Horizons images hint at rare atmospheric formation. By Christopher Crockett, 3:05pm, October 19, 2016: here.
WE’RE STILL MOURNING PLUTO’S PLANET DEMOTION But there might just be another ninth planet out there. [NYT]
New gravity data from recent Cassini flybys of the giant planet suggest that Dione’s crust floats on an ocean 62 miles below the surface, and may harbor microbial life.
Dione’s ocean is about 100 kilometers below the surface and is roughly 65 kilometers deep, Mikael Beuthe, a planetary scientist at the Royal Observatory of Belgium in Brussels, and colleagues report. They inferred the ocean’s presence from measurements of Dione’s gravity made by the Cassini spacecraft, which has been in orbit around Saturn since 2004.
