On October 28, 2015 Cassini passed below (above?) the south pole of Enceladus at an altitude of 49 kilometers. The probe was flown here in order to get a taste of the water-ice particles that are streaming out into space from Enceladus’ suspected sub-surface ocean in this location. This is the lowest pass Cassini has made through the alien ocean geyser.
This was done in order to help scientists understand the nature of the ocean, how close to the surface it might be, and if the water contained in it could accommodate life. Also of particular interest, the Cassini team is looking for a particular chemical signature of hydrogen that could support the theory that Enceladus has hydro-thermal vents heating water deep in the moon’s ocean.
Related reading: Water, water everywhere!
It’s important to note, however, the instruments Cassini carries on board can characterize the chemical composition of any particles it encounters, but it doesn’t have the ability to directly test for life.
The detailed analysis of the tiny water droplets that Cassini caught as it flew through the plume is now underway (with full results a few weeks away), but some images of the fly-by have already been sent back. And as we’ve come to expect from Cassini, they’re spectacular.
The south polar region of Saturn’s active, icy moon Enceladus awaits NASA’s Cassini spacecraft in this view, acquired on approach to the mission’s deepest-ever dive through the moon’s plume of icy spray. The wavy boundary of the moon’s south polar region is visible at bottom, where it disappears into wintry darkness. CREDIT: NASA/JPL-Caltech/Space Science Institute
A RAW and unprocessed image from Cassini as it flew towards the icy plume at Enceladus’ south pole. CREDIT: NASA/JPL-Caltech/Space Science Institute
During its closest ever dive past the active south polar region of Saturn’s moon Enceladus, NASA’s Cassini spacecraft quickly shuttered its imaging cameras to capture glimpses of the fast moving terrain below. This view has been processed to remove slight smearing present in the original, unprocessed image that was caused by the spacecraft’s fast motion. CREDIT: NASA/JPL-Caltech/Space Science Institute
Following a successful close flyby of Enceladus, NASA’s Cassini spacecraft captured this artful composition of the icy moon with Saturn’s rings beyond. This view looks towards the trailing/anti-Saturn side of Enceladus. North is up. The image was taken in visible light with the Cassini spacecraft wide-angle camera on Oct. 28, 2015. The view was acquired at a distance of approximately 171,000 km from Enceladus and at a Sun-Enceladus-spacecraft, or phase, angle of 141 degrees. Image scale is 10 km per pixel. CREDIT: NASA/JPL-Caltech/Space Science Institute
For 12 hours in 2006 Cassini passed into the shadow of Saturn
Cassini launched in October 1997 along with the European Space Agency’s Huygens probe. The probe was equipped with six instruments to study Titan, Saturn’s largest moon. It landed on Titan’s surface on Jan. 14, 2005, and returned spectacular results.
Meanwhile, the Cassini probe’s 12 instruments have returned a daily stream of data from Saturn’s system since arriving at Saturn in 2004.
Among the most important targets of the mission are the moons Titan and Enceladus, as well as some of Saturn’s other icy moons. Towards the end of the mission in 2017, Cassini will make closer studies of the planet and its rings.
The image featured at the top of this page is one of the most stunning images I have ever seen. It was taken in 2006 when Cassini passed into the giant shadow of Saturn. It is a composite of 165 images taken by the wide-angle camera on board Cassini, and then compiled together. Colour in the view was created by digitally compositing ultraviolet, infrared and clear filter images and was then adjusted to resemble natural colour. Cassini was about 2.2 million kilometers above Saturn when it captured these images, and about 15 degrees above the ring-plane.
Two new sets of rings were discovered when scientists looked at Saturn in that image, as we had never seen it like this before.
And the part that makes this image all the more beautiful: you can even see Earth, a tiny dot just above the main rings on the left side of the image. Earth is about 1.5 billion kilometres away – the pale blue dot that we all share. To spot Earth in the image at the top of the page you’ll probably need to click on the image to view it in full size, because Earth is just so small.
Earth is 1.5 billion km away in this image
For more on the Cassini mission (including some of the most amazing images you’ll ever see), here is the mission homepage: http://saturn.jpl.nasa.gov/index.cfm.