I can almost touch Uranus from here.
To give you a concept of how far out Saturn is, let's consider the distance from the Earth to the sun. This distance has been calculated as 8 light-minutes, or a distance equal to that travelled by light in a vacuum in 8 minutes. This 8 light-minute distance is used as a unit of measurement called an AU, short for "astronomical unit," and provides the foundation for our sense of distance in the solar system. The entire inner solar system, which includes Mercury, Venus, Earth, Mars, and their attendant satellites (Luna, for Earth, and Phobos and Deimos, for Mars) occupies an area around the sun with a radius of 1.5 AUs, or 12 light-minutes. By contrast, Jupiter, the first world of the outer solar system and the largest planet anywhere in our solar system, orbits at approximately 5.2 AUs. This means that Jupiter orbits at more than five times the distance of the Earth from the sun. Saturn, even more distant still, orbits at 9.5 AUs. If we run the math, under ideal circumstances, when Saturn and Earth are on the same side of the sun, a radio transmission from Earth to Saturn (radio, of course, being a form of light) would require 68 minutes to make the trip, one way. When Earth and Saturn are on opposite sides of the sun, this time increases to 84 minutes. Needless to say, flying the Cassini is not much like flying a model airplane. Not unless you fly planes where every time you send a command, you can stop and watch a major motion picture before you find out if the plane responded.
For the truly obsessive, Pluto, which is either the most distant planet or the largest of the new Trans-Neptunian Objects, orbits at approximately 39.5 AUs, meaning that under ideal conditions a signal from Earth would require approximately 5 hours to arrive. Be sure to pack a lunch. Of course, Pluto's orbit is more elliptical than the other planets, and actually crosses inside Neptune's orbit periodically, so the actual communications lag can vary considerably.
Getting back on topic, Saturn is also an enormous world, massing approximately as much as 95 Earths, and playing host to 20 known moons, in addition to its magnificent rings. Among these moons is the giant Titan, which masses almost twice that of our own moon, and is larger than the planet Mercury. Amazingly, Titan also has an atmosphere thicker than that of our own Earth, and we have reason to believe that it may play host to organic compounds and, some have speculated, simple forms of life. Unfortunately, Titan's atmosphere has long frustrated attempts to explore its surface, as it obscures the surface from our sensors. All that will soon change, however, thanks to both Cassini's sophisticated instruments, and the Huygens probe.
The Huygens, currently riding shotgun on Cassini, will descend into Titan's atmosphere, collecting information and, it's hoped, giving us at least a few minutes of operation on the moon's surface. While it's impossible to say whether or not speculation about life will be ended by this probe, this represents the first important step in exploring an enormous body about which we are almost totally ignorant.
All in all, the Cassini mission promises to give us an amazing look into the physics of the solar system's second largest planet (the largest, of course, being Jupiter, which weighs in at a staggering 318 Earth masses) and interested parties can follow the news about Saturn at this website.
Now, many of you are probably thinking, "And how much has this boondoggle cost us?" Well, the simple answer is... a lot. The more complicated answer is... a lot, but a LOT less than the average farming subsidy or corporate tax break. "So," you continue, "Couldn't we spend this money better on something else?"
Well, maybe, but the question is... what? I mean, let's be honest, back in the days when Galileo was being forced to recant his assertion that the sun is at the center of the solar system, the same claim might have been made. Wouldn't such a brilliant man be better used devising new ways to build cathedrals, so as to earn God's favor? Likewise, wouldn't it have seemed wiser to spend money on poor relief than on developing chemistry? Certainly it would have, but without chemistry much of our modern technology would be impossible. Truly revolutionary science or learning, rarely seems worth the trouble save in hindsight.
Whatever your views on the space program, basic science has rarely failed to pay off, and this is definitely basic science. What can be more basic than "What is our neighborhood like?" How can we pretend to be a great species, or a wise society, if we turn a blind eye to the 'music of the spheres'? Yet, still, if none of these ideas provides a rationale that satisfies you, here are a few more. Find your group in the list below and see what YOUR reason for continued space exploration is.
If you are religious:
Without knowing your faith, I can only say this- If god created the universe, then he has created a truly vast place full of wonder and majesty. What, in turn, could be more disrespectful of him and his will than to conclude that none of it matters?
If you aren't religious:
If there is no god, then it behooves us to understand our world. We are as much a part of the universe as we are our terrestrial environment- as the dinosaurs learned all too late.
If you are concerned with social justice:
Traditionally the two most lucrative sources of advanced, revolutionary technology have been the military and the space program. You let me know which one you prefer, I'll wait.
If you've ever asked questions like, "Can the subaltern speak?":
Ok, seriously, get the hell off of my website. The answer, by the way, is "No." Fuck you for asking a question that presupposes its own answer.
If you study something like "Post-colonial, post-modern, masculinities in a neo-feminist context":
Ok, let's just all remember that saying about people who live in glass houses.
If you do solid, empirical social science:
Hey, if we don't criticize the physicists, maybe we can get them to not criticize us, and then everyone gets more money from the NSF. A round of grants for everybody!
If you're starving in a peripheral state:
Well, in the first place, it isn't as though the presence of the space program is the decisive factor in your oppression. In the second place, the busier the core is with space, the less time they have to monkey with you. It isn't much, but let's be realists.
If you have even a smidgen of curiosity:
I don't have to convince you at all, you've been convinced since about the second paragraph.
And, as long as we're talking about space,and other far-out stuff, why not take a look at this? Scroll down to the one named "Lucy in the Sky with Shatner." Requires windows media player or Quicktime, but hoo-boy is it ever worth it.
Figures on planetary masses and orbital radii taken from: "Astronomy: A Beginner's Guide to the Universe" by Eric Chaisson & Steve McMillan. Prentice Hall. 1998.