The Cassini mission was a collaboration between NASA, ESA and ASI (Italian Space Agency) to send a spacecraft to study Saturn and its moons and rings.
Launched on 15th October, 1997, the spacecraft was active in space for over 18 years, of which it spent 13 years orbiting Saturn (entered in Saturn’s orbit on 1st July 2004). The mission ended on 15th September 2017, when the probe was commanded to crash itself into Saturn’s upper atmosphere. The mission achieved success beyond expectations. It has revolutionized human understanding of the planet Saturn, including its rings and moons, as well as knowledge of where life might be discovered in the Solar System.
The probe was initially planned to last for 4 years on Saturn’s orbit. It was extended for another 2 years until 2010 and they gave this extended mission a name, Cassini Equinox Mission. Later, the mission was again extended (for 2nd time) with a new name Cassini Solstice Mission, which lasted another 7 years.
Throughout its mission, the probe took thousands of photos that help us imagine what is potentially out there in far, never-ending space. We’ve gathered some of the most stunning images captured by Cassini probe that make us contemplate our place in the vast universe.
It’s an image of the entire Earth, as observed from the dark side of the planet Saturn. This shows how small we are; just a speck of dust.
The hexagon cloud pattern around Saturn’s north pole does not shift in longitude like other clouds. The hexagon sides are longer than the diameter of Earth – 13,800 kilometer.
At the very center of hexagon is a vortex that looks like a an incredible, giant red rose surrounded by green foliage in this false color image.
These images were taken on 14th January 2005, by Huygens probe at different altitudes. The last image was taken when probe was landed on the Titan surface. It saw a rocky landscape billions of miles away from us.
The Glorious Rings
Unilluminated side of Saturn’s rings, 9th May 2007
Icy rings shine in scattered sunlight
Highest-resolution color picture rings, till date
Saturn projects a shadow on its rings
Propeller patterns in the rings, created by small moonlets that form in the rings
The rings orbit around Saturn and consist of billions of small particles, ranging from Micrometer to Meter in size. The particles of ring are mostly made of water ice and rocky materials. The rings have several gaps where density of particle reduces sharply. We still don’t know how exactly these rings formed. However, theoretical model suggests that they were formed early in the history of Solar System.
Plumes on Enceladus
Cassini found water rich plumes on Enceladus (6th largest moon of Saturn). The south pole region of the moon shoots molecular hydrogen, geysers-like jets of water vapor and other solid material like ice particles, sodium chloride crystal, totaling around 400 kilogram per second.
Pan, Walnut-Shaped Moon
Even small things are quite astonishing around Saturn. Cassini captured a small oddly-shaped moon, which is 35 kilometers across and 23 kilometers wide. It orbits within the Encke Gap in A ring of the Saturn. It keeps Saturn’s Encke Gap free of ring particles.
Cassini aircraft takes an image of Saturn backlit by the sun. The lighting reveals the gauzy texture of the rings and faint, icy outermost F-ring. This panoramic view is made by joining 165 images captured by the Cassini’s wide-angle camera for over 3 hours, on 15th September, 2006. Color is in this picture was made by digitally compositing infrared, ultraviolet and clear filter photos and was further modified to resemble natural color.
Titan is the largest moon of Saturn, discovered way back in 1655. Cassini and Huygens gave us a detailed view of Titan – which is much like planet Earth and it has nitrogen-dense atmosphere, where methane-rain, along with other liquid hydrocarbon-rain is usual. It has mountains, lakes, rivers and volcanoes. This is an infrared image, revealing some surface features.
Titan Orbiting Saturn
Saturn’s largest moon orbit at 20 Saturn radii, once every 15 days and 22 hours. Titan synchronously rotates with Saturn, so it shows only one face to the planet, which makes one day of Titan equal to its orbit period.
The Last Image
The very last photos of Cassini took before it shut down its camera and prepared to be crashed on Saturn’s upper atmosphere. It’s the icy moon Enceladus setting behind Saturn.
Read: 40 Years of Voyager: Still Active and Reaching stars
Over the past few weeks, NASA captured some final shots. They are magnificent, but a bit sad. There is no guarantee NASA or any other space agency ever send a probe back to Saturn.