IT’S BEEN A GOOD RUN “NASA’s Cassini spacecraft will end its groundbreaking 13-year mission to Saturn on Friday with a meteor-like plunge into the ringed planet’s atmosphere, transmitting data until the final fiery moment.” [Reuters]
These are Cassini’s parting shots of the Saturn system: here.
R.I.P. Cassini. After 20 years, nearly 300 orbits and pioneering discoveries, the spacecraft plunges to its death in Saturn’s atmosphere. By Lisa Grossman, 9:08am, September 15, 2017.
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.
As Cassini’s tour of Saturn draws to a close, a look back at postcards from the probe. NASA’s veteran spacecraft has revealed a lot about Saturn in its more than 20 years in space. By Lisa Grossman, 3:45pm, August 23, 2017: 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.
Satellite smashups could have given birth to Saturn’s odd moons. Weird moons orbiting the ringed planet might have been forged from head-on collisions. By Christopher Crockett, 11:00am, May 21, 2018.
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.
