Unless you are dead to all finer emotion, the picture of NASA's Phoenix lander gently descending toward the surface of Mars made you feel something. But the (so far) successful mission is ground-breaking in several other ways, beyond the sheer technological achievement of creating and transporting Phoenix to Mars, achieving a perfect landing, and having the complex machinery unpack and deploy successfully.
My favorite comment on Phoenix's landing comes from Phil Plait of the Bad Astronomy blog, talking about the image of Phoenix hanging from its parachute: "Think on this, and think on it carefully: you are seeing a manmade object falling gracefully and with intent to the surface of an alien world, as seen by another manmade object already circling that world, both of them acting robotically, and both of them hundreds of million of kilometers away.
Never, ever forget: we did this. This is what we can do."
Bill Higgins, commenting (comment #5) on Making Light points out that on the ground we've got both Mars rovers and now Phoenix while, orbiting the planet, we (and by "we" I mean the planetary we) have the European Space Agency's Mars Express, NASA Odyssey, and NASA Mars Reconaissance Orbiter. It isn't 2001 or any of the other space exploration scenarios as depicted by Heinlein and Hollywood, but it's the closest we've ever gotten to planetary exploration.
Visibility
The other thing that's more noticeable with this landing is the sheer amount of information available online. For instance, you can visit the Mars Phoenix mission page at NASA, stay on top of Phoenix and its activities by checking its page on Twitter, read the team blog, and follow a positive forest of links to find out about the technology, the people, the challenges—the whole ball of wax. I'm positively agog to see what Phoenix will discover as it conducts its mission over the next month.
And if a bunch of curious kids get the space, science, and engineering bug as a result of the pictures, coverage, and video of happy engineers celebrating an epic achievement when Phoenix touched down, light as a feather, on the surface of Mars? I happen to think that's the best result of all.