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| Cassini-Huygens spacecraft |
In October 1997 the Cassini-Huygens spacecraft began its incredible seven-year travel towards the magnificent planet Saturn.
The spacecraft launched with two elements the Cassini orbiter that was designed to study the Saturn system and its passenger the Huygens probe that was destined for the mysterious moon Titan because of its size and weight.
Cassini was unable to travel directly to Saturn instead the heavy spacecraft performed multiple gravity assist maneuvers in order to increase its velocity and reach the ringed world.
It's first encounter was with Venus where it received to gravitational boosts. Then for nearly two years after its launch Cassini briefly came home when it passed within 700 miles of our blue planets receiving another gravity boost that accelerated the spacecraft to a speed of around 13,400 miles per hour relative to the Sun.
During the flyby Cassini passed the moon where it used the opportunity to calibrate its camera and capture its first photograph of the journey although Cassini was nearly as close to Earth as it had been shortly after its launch the successful flybys enabled the spacecraft to escape the Sun's gravitational pull and eventually reach its destination. But before Cassini could arrive at Saturn it would first have to fly by our solar system's largest planets for one more boost far beyond the asteroid belt.
Cassini eventually encountered Jupiter in December 2000 from a distance of approximately 6.2 million miles away. It took about 26,000 images of the gas giants, it's faint rings and its many moons were taken during the flyby. It took most detailed global color portrait of Jupiter ever produced. It reveals the planets parallel reddish brown and white bands, it's white oval storms and it's giant famous storm the great red spots. A closer look at Jupiter during the flyby also revealed an incredible view of the Galilean satellites Io.
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| Io |
For over four years Cassini coasted through the darkness of space until February 2004 when the spacecraft began its final approach to the ringed world this strikingly beautiful image of Saturn was created using a series of exposures taken by Cassini's narrow angle camera from 43.1 million miles away the image contrast and colors have been slightly enhanced so that we can see the finer details of the magnificent planet such as the subtle color differences within Saturn's atmosphere the structure of its huge bright rings.
During its final approach Cassini observed colossal storms within Saturn's atmosphere as they merged into one and discovered two small moons that have been named Metheny and Pelini but Cassini's first close encounter was with the dark moon Pheobe.
After the successful flyby of Phoebe, Cassini entered into orbit around Saturn in July 2004 becoming the first spacecraft ever to orbit the ringed world. For months Cassini beamed back thousands of images including some incredible photographs of the large hazy moon Titan. Until the Cassini mission, little was known about Saturn's largest moon other than its slightly larger than mercury and that its surface is covered with a thick nitrogen-rich atmosphere.
In October 2004 Cassini successfully skimmed the atmosphere of Titan coming within 750 miles of its surface in these near infrared images clouds can be seen covering strange features that run from east to west. The features appear to be surface streaks that may have been caused by the movement of liquid. Just a few months later in December 2004 Cassini sleeping passenger the Huygens probe successfully detached beginning its three-week journey to Titan surface. In January 2005 at first the Huygens probe could only capture the thick orange brown fog that shrouds the moon but as the fog started to clear at around 37 miles above Titan large never-seen-before features slowly became visible. The probe appears to land in a dry riverbed however the liquid that flowed here was not water but methane. Many small pebble like rocks can be seen scattered across the moon's hazy landscape and small hills. A few meters in height are visible in the distance during the probes historical trip to Titan. Cassini was also encountering a strange moon called a Pitous.
In March 2006 Cassini began capturing rare images of the frigid moon Enceladus as Jets of water ice spew out into space during a close flyby of Enceladus. Cassini sampled the icy plume directly and detected a brew of volatile gases water vapor carbon dioxide and carbon monoxide as well as some organic material. These icy plumes indicates that the frigid moon has a large-scale saltwater ocean below its thick crust. After four long years of orbiting Saturn Cassini completed its primary mission. The spacecraft revealed wonder after wonder increasing our knowledge of Saturn and unraveling many of its greatest mysteries but Cassini wasn't finished yet. In July of 2008 it started the first of multiple mission extensions. Cassini completed over a hundred flybys of Titan and captured thousands of images of the hazy moon Titan. Titan is one of the most earth-like places in the solar system but vastly colder and with a very different chemistry. The darkest areas are huge lakes of liquid methane and ethane that are surrounded by shorelines hills dunes and long drainage channels. In August 2008 during another close encounter with Enceladus. Cassini identified the icy jets which were erupting from the moon's southern region and shows us an extreme area of tiger stripe like fractures within the icy crust.
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| Saturn |
It is believed that Saturn's intense gravity causes the moon to stretch and compress creating friction which generates heat and pressure forcing the underground water out through the thick icy crust where the liquid instantly freezes on contact with the cold temperatures of space. During its time orbiting Saturn Cassini also studied to the size, temperature, composition and distribution of the planet's rings over many years while beaming back thousands of magnificent images.
For nearly thirteen years Cassini completed multiple flybys of the gas planet and its many moons. While beaming back over four hundred and fifty thousand images it discovered six new moons collected over six hundred and thirty-five gigabytes of scientific data. It completed 294 orbits of Saturn and traveled four point nine billion miles during its time in space. The spacecraft was extremely successful over its multiple missions but in April 2017 Cassini's propellant was almost too depleted and the remarkable spacecraft entered the last part of its mission the grand finale at the end of its nearly two decades long historic mission. Cassini made its last close flyby of Titan and used the moon's gravity to reshape its trajectory placing it into an orbit that would enable the spacecraft to explore the 1200 mile gap between Saturn and its rings. Then in September 2017 in the skies above this alien world the Cassini mission had finally come to its end. This incredible spacecraft that started on our little blue planet nearly a billion miles away plunged directly into Saturn's atmosphere burning up like a meteor and becoming a part of the gas giants forever.