On July 1, 2004, NASA’s Cassini spacecraft arrived at Saturn’s orbit seven years after launching from Earth in 1997. Within ten years after arriving at the majestic gas giant, Cassini profoundly changed our understanding of the dynamic atmosphere of the planet, rings and moons. Now the mission is entering the last stage of its prolific Saturnian Odyssey, and the organizers hope that the fuel remaining on board will be enough for a series of bold “proximal movements” through the planes of the rings in 2016; the final stage is called the Grand Final Cassini.
Black and white image of Saturn and Titan crescents, published by NASA.
Cassini's Grand Final: The scientific end of Saturn’s bold mission from the beginning of its arrival to orbit was nothing short of amazing, so let's just take a small snippet of key discoveries and stunning observations posted on the last 12 months, as Cassini went through the 10th year of the Saturn study through history books.
The Hexagon, carved in the upper atmosphere of Saturn at its north pole, is one of the longest secrets of the solar system — the first observations were made by Voyager probes in the early 1980s. It was believed that this was caused by high-altitude jet streams. The hexagon recently captured during the Cassini mission also appears to rotate with the inner core of Saturn and the global magnetic field. Although the dynamics underlying the flow of this phenomenon is not entirely clear.
There are several worlds that are considered more promising than Saturn’s largest satellite, such as Titan. The moon is known to have a very dense atmosphere, large accumulations of liquid methane and ethane, a hydrocarbon-rich landscape filled with rivers and valleys, and vast fields of dunes. Someone may be mistaken in thinking that this moon is the Earth in its infancy, filled with organic potential. It may be frozen and uninhabitable, as we know it, but astrobiologists dream of a follow-on mission to Titan after Huygens's descent module (which was aboard Cassini when flying to Saturn) landed and landed on the moon in 2005. May Does Titan be older than Saturn? To add the similarity of Titan with the young Earth, Cassini discovered waves in one of the major seas of Titan under the influence of surface winds. Here you can see how the waves, shown at an oblique angle, reflected in the sunlight.
Having increased the image of the dunes on the vast fields of Titan during several spans, Cassini showed us even more eolian (influenced by the wind) earth-like features. In the case of the black dunes of Titan, the fine grain organic compounds chased by the wind were collected into peculiar rippled "seas".
Using high-resolution cameras, Cassini captured countless amazing pictures of 62 satellites of the planet. In the picture you see one of the favorites of Vkosmose.com readers: Saturn's moon Mimas looms ominously with the smaller moon Pandora moving behind. Mimas also has the nickname "Death Star" in reference to Star Wars, with the great crater of the moon, Herschel, resembling the super-weapon of the Death Star, which destroys the planets.
When it comes to organic chemistry, not everything is about Titan. Enceladus’s small ice moon is known not only for its impressive water-rich geysers, which resemble birth chemistry, but it is also likely that the moon has vast seas of liquid water beneath the surface. It's almost like mini-Europe, Jupiter’s second largest satellite, and scientists are eager to find out what lies under the cracked crust of both moons.
As an amazing discovery this year, Cassini managed to observe something in one of Saturn's rings. Can this bright growth in the outer edge of the gas giant's ring be the birth of a new moon? Astronomers believe that this is possible by providing new clues regarding the formation of natural satellites and proving that although our solar system is old, its planets are still in the active process of star formation, which has been preserved to this day.
Like Saturn’s strange hexagon, the bright “spokes” in Saturn’s rings have puzzled astronomers for some time. Originally seen by Voyagers during flights in the early 1980s, Cassini later observed these phenomena and showed that they were not caused by gravitational interactions in or around Saturn. Instead, they are most likely due to the interaction between dust particles in the ring B of the planet and Saturn’s global magnetic field passing through the ring system.
In an exciting observation, Cassini discovered the influence of one of Saturn’s tiny moons on the outer ring of the planet. Prometheus, who is only 53 miles across, periodically rolls through ring F, creating channels and ribbons as he passes through ice particles.
At one of the most iconic satellite images in July 2013, Cassini looked back at Earth at a distance of almost 900 million miles. The earth looked like a mere speck of light, and the moon was even smaller. This image reminds us, like the famous Voyager photo "Pale Blue Dot" in the 1990s, how tiny we are compared to the vastness of space, and Cassini continues to inspire people on our small planet that we can do great things.