Category Archives: Saturn
Just a week after Curiosity celebrated its first Martian year in Gale Crater and we have yet another milestone anniversary in Solar System exploration: as of 10:48 p.m. EDT tonight Cassini will have been in orbit around Saturn for a full decade!
“There are times when human language is inadequate, when emotions choke the mind, when the magnitude of events cannot properly be conveyed by the same syllables we use to navigate everyday life. The evening of June 30, 2004 was such a time.”
– Carolyn Porco, Cassini Imaging Team Leader, CICLOPS “Captain’s Log” on June 30, 2014
That’s ten years and over 2 billion miles of discoveries and explorations of our Solar System’s most majestic planet and its incredibly varied family of moons. Over the course of its primary mission and three extended missions, we have been able to get a close-up look at Saturn and its moons like never before, witnessing first-hand the changes that occur as their seasons change. What’s been discovered by the Cassini mission about Saturn has offered invaluable insight into the evolution of our entire Solar System, as well as planets that could be found elsewhere in our galaxy.
“Having a healthy, long-lived spacecraft at Saturn has afforded us a precious opportunity,” said Linda Spilker, Cassini project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California. “By having a decade there with Cassini, we have been privileged to witness never-before-seen events that are changing our understanding of how planetary systems form and what conditions might lead to habitats for life.”
Launched on October 15, 1997, the Cassini-Huygens spacecraft established orbit around Saturn on June 30, 2004 (July 1, UTC).
If you’ve been a faithful reader of Lights in the Dark over the past five years you know that I just love Cassini (and you probably do too!) In orbit around Saturn since 2004, Cassini has taken us on an intimate tour of the Saturnian system for a decade now, revealing the incredible beauty of the ringed planet and its family of moons like no spacecraft ever has before. Thanks to Cassini and the Huygens probe, we have seen the surface of Titan for the first time, witnessed the jets of Enceladus, discovered many previously-unknown moons (and moonlets) and basically learned more about Saturn over the past ten years than since Galileo first pointed his telescope at it.
Although nearing the end of its life span, Cassini still has a few good years left and scientists are taking full advantage of its remaining time around Saturn to learn as much as they can before the spacecraft makes its final dive into the planet’s atmosphere in 2017.* The video above shows what awaits Cassini in the years ahead — some of its best discoveries may be yet to come. Check it out!
*The exact plan for the end of Cassini’s mission has not yet been finalized.
Earth isn’t the only planet with auroras — any world with a magnetic field and an atmosphere can get a light show around its poles when its star’s wind is blowing hard enough!* The image above shows Saturn’s northern lights, as seen in ultraviolet light by the Hubble Space Telescope’s Advanced Camera for Surveys in April 2013.
See the full lineup of images below:
You don’t typically see Saturn’s rings looking like this, but then you can’t see in ultraviolet like Cassini (or many insects) can! The image above was acquired by the UVIS (UltraViolet Imaging Spectrograph) instrument aboard the Cassini-Huygens spacecraft on June 30, 2004, just as it was entering orbit around Saturn.
The area shown here is about 10,000 km (6,200 miles) across. It’s a small section of ring segments… just a portion of Saturn’s magnificent expanse of rings. Part of the C ring, toward Saturn, is along the left, and the inner edge of the B ring begins just right of the center. The colors are related to the composition of the ring particles; blue and green colors are from bright water ice, reds are rings with darker, “dirtier” particles.
While the colors aren’t “real” per se — our eyes simply can’t see UV light — the association of colors we can see to specific UV wavelengths allows scientists to accurately observe relative differences in the ring segments.
“It is cool that we can pick our own colors in the pictures we produce,” said Dr. Larry W. Esposito, a professor of Astrophysical and Planetary Sciences at the University of Colorado and UVIS Principal Investigator. “No person has ever seen ultraviolet light, although some butterflies can. Our pictures may thus represent a ‘butterfly’s-eye view’ of the Saturn system.”
Click the image to access a higher-resolution image on ESA’s Flickr page, and read more about the Cassini mission here.
Congratulations! It’s a baby… moon? A bright clump spotted orbiting Saturn at the outermost edge of its A ring may be a brand new moon in the process of being born, according to research recently published in the journal Icarus.
“We have not seen anything like this before,” said Carl Murray of Queen Mary University in London, lead author of the paper. “We may be looking at the act of birth, where this object is just leaving the rings and heading off to be a moon in its own right.”
The weather forecast for Titan? Cloudy, hazy, and cold — just like every other day! The image here is a color-composite made from raw data captured by Cassini during a flyby on April 7, 2014, and it shows a look at the two main features of Titan’s atmosphere: a thick orange “smog” made of organic compounds created by the breakdown of nitrogen and methane by UV light, and a wispy blue upper-level haze composed of complex hydrocarbons.
Cassini was approximately 19,076 miles (30,700 km) from Titan when these particular images were captured.
It’s been suspected for nearly a decade that Saturn’s 315-mile-wide moon Enceladus harbors a hidden ocean beneath its frozen crust, thanks to observations by the Cassini spacecraft of icy plumes spraying from its southern pole, and now scientists have even more evidence supporting its existence: Doppler measurements of the moon’s gravity taken during Cassini’s flybys show variations indicative of a subsurface southern sea as deep as the Pacific’s Mariana Trench!