the cassini-huygens mission to saturn

the sixth planet from the sun, saturn, is probably best known for its extraordinary rings which were first observed by gallileo galilei in 1610. i’ve been following the cassini-huygens mission to saturn and titan since it was first launched in 1997.

at that time my class and i did a heap of research on the net and watched as the spacecraft was assembled on real-time cameras. an extraordinary experience when you consider how relatively long ago that was. since then as each successive class has passed through my room we have spent some time looking at the wealth of information that has come out of what i think is the most extraordinary space mission since the apollo missions to the moon.

the mission bears the names of two men. the italian mathematician, astrologer, and astronomer giovanni cassini who was the first to observe four of saturn’s moons. also christiaan huygens, who hailed from holland, a mathematician and astronomer who discovered saturn’s moon titan as well as examining saturn’s rings and discovering that those rings consisted of rocks. both men hail from the seventeenth century.

at the time of its launching, the mission ran into controversy as concerns ran high over the amount of plutonium the spacecraft was carrying (32.8 kg) and the potential disaster that would ensue were the rocket to run into trouble. happily the liftoff and subsequent exit from earth’s atmosphere passed without incident and cassini-huygens was able to embark on its six year, seven month, and sixteen day journey from earth to saturn.

nasa has been incredibly generous and transparent in its sharing and presentation of data that has been gathered by the cassini-huygens mission often posting raw data as and when it appears to them. the volume of material available is happily staggering. countless videos, thousands of still shots, and animations, of every stage and event in the mission. these can all be accessed here.

the most recent major event is a close flyby of enceladus, one of saturn’s moons that has among other things the unique feature of spouting huge geysers of frozen particles from its south polar region.
here’s what nasa says will happen:

“this flyby will be cassini's closest approach to enceladus so far, the fourth and final enceladus flyby of the four-year prime mission, and the first of four close brushes with this moon that have been proposed for 2008. At closest approach, the spacecraft will be only about 50 kilometres above the surface of enceladus, and will pass the moon at a speed of about 14 kilometres per second. enceladus is 505 kilometres across . . . while flying through the plume, cassini's altitude will be 200 kilometres from the moon.” imagine. nasa is able to instruct and control a vehicle to fly within fifty kilometres of the surface of an object more than seven hundred and ninety four million miles away!

nasa’s investigations of enceladus so far have revealed:
• the presence of a strange atmosphere concentrated at the south pole
• an atmosphere that is mostly (91%) water vapour, but with some nitrogen, carbon dioxide and other simple carbon-based molecules (organics)
• large crevasse features at the south pole termed “tiger stripes”
• an intriguing hotspot at the south pole - anomalous warmth in the area of the tiger stripes shown here . . .

• the presence of simple organics along the fractures
• indications that water vapour and fine material are being ejected from tiger stripes

to learn more about the most recent findings relating to enceladus then visit this page and view the excellent and informative video.

apparently there are fractures in the surface at the south pole that are considerably warmer than they should be leading to conjecture that a body of liquid - possibly water - resides under the surface. the thinking is that a fly through of the geysers might reveal the presence of microbial lifeforms.
animated and narrated video of this event can be viewed here.

here’s an image of the surface of enceladus taken on march 12th, 2008.

here’s the news release to accompany this event.
most amazingly, the nasa team connected to this project blogs their way through their experiences and discoveries so that we can read and share their excitement on the fly!