Happy Birthday Cassini!

Credit: NASA/JPL-Caltech
Image source

Cassini rode into space Oct. 15, 1997, atop a U.S. Air Force Titan IVB. Its mission: to orbit and study the Saturnian system for four years and to put the European Space Agency's Huygens Probe in position to parachute down to the frozen surface of Saturn's Earthlike moon Titan. Since entering orbit around Saturn, Cassini's scientific instruments, powered by radioisotope thermoelectric generators, have returned immense amounts of new information via NASA's global Deep Space Network to the international team of scientists working on the mission.

Read the rest.

Presumably as a birthday present of sorts, the Cassini team have released quite a number of colour images onto the Photojournal, in particular this gorgeous portrait of the Saturnian system as it appears from out by Iapetus (click to enlarge):

Credit: NASA/JPL/Space Science Institute
Image source with more information

The little (and not so little) specks around Saturn are, from left to right, Dione, Enceladus, Mimas, Rhea, Tethys and Titan. Quite the family portrait. No Iapetus, because it's on the wrong side of the camera. (This image is a surprisingly small file size for such a huge vista (~75kb), however Blogger has seen fit to shrink it down a bit. Blogger, you cheeky monkey! Click the source to find the 3400 x 1000 version and answer the question, "Where's Mimas?")

Credit: NASA/JPL/Space Science Institute

Image source with larger version

This one's a view of Saturn from 'above', with the rings appearing slightly dim in order to avoid over-exposing the planet itself. It's an image that's big on both beauty and file size, so, once again, click the source for the high-resolution version if you like it.

Finally, as a reminder that Cassini is our robotic photographer out by Saturn, often as interested with art as science, here's a little optical effect it sees from time to time while looking at the rings:

Credit: NASA/JPL/Space Science Institute
Image source with more information

The effect is 'real', which is to say that if you were orbiting Saturn yourself, you could see it with your own eyes, however the variety of colours it shows here are a byproduct of the way Cassini takes colour photos: by taking red, green and blue images in quick succession and then combining them. Here this process has turned a mere spot of light into a beautiful rainbow smear. (The optical effect itself is explained here.)

Time was nuclear-powered robots were only figments of our imaginations, and usually fearful ones at that. Perhaps atomic automata will one day stride through our cities blasting us with their death rays. If it comes to that, I hope we'll remember that one of the first of their race was the quiet sort, mostly interested in pretty pictures and scientific measurements.