What's our fascination with Mars?

By Sophia Dengo CNN - When you look up basic information on Mars on NASA's website, in the field for the name of the discoverer, it says "known by the ancients." Unlike Neptune, and the no-longer-a-planet Pluto, Mars has always figured in to the way we understand our solar system.

If you know what to look for in the sky, the reason why is obvious enough: Mars is visible to the naked eye, and clearly red. It's also close: our ability to see it with the naked eye attests to the relative nearness of the planet.

Pop culture is loaded with references to Mars: witness movies with titles like "Mission to Mars" (2000) and "Red Planet," (2000) documentaries like NOVA's "Can we make it to Mars?", not to mention numerous science fiction stories like Ray Bradbury's 1950s "The Martian Chronicles," and non-fiction books like "The Case for Mars," and of course "Packing for Mars," which both explore what it would take to send not just a robotic analog for humanity, but actual living, breathing people.

Mary Roach, author of "Packing for Mars", finds her fascination with Mars is a lot more personal.

"I picture myself in the landscape, sitting on a rock in this or that panorama shot, and what that would feel like, be like. The more real the images become, the more it fascinates me."

At 1:31 a.m. eastern on Monday, August 6, our fascination with Mars continued when the Mars Science Laboratory (MSL, or Curiosity) landed on the Red Planet. It's not the first rover humans have sent to Mars: NASA has been sending robotic emissaries since Viking 1 landed in 1976.

Because Curiosity is the latest in a long line of Mars-bound spacecraft, this mission begs the question: Why do we seem to love it so much?

@CNNLightyears posed the question to many asking people why they love Mars. The responses on Twitter and Facebook varied in details, but the gist of them was effectively the same.

Cindie Hurley, a space enthusiast, sums it up via Facebook: "It's the 'new world' of space... If the moon was an offshore island, well Mars is that distant continent...it's only the FIRST step in a much bigger journey. If we can get there, then maybe, just maybe, we can get to the next destination."

Mars, even with its inhospitable atmosphere and barren landscape, is the closest analog to Earth that we're aware of.

James Wray, an assistant professor of Earth and Atmospheric Sciences at Georgia Tech who collaborated on Curiosity's SAM (Sample Analysis at Mars) suite of instruments, tells us, "It's the most "Earth-like" planet we've yet found, with mountains, canyons, dry river valleys, rocks, sand and dust of compositions and appearances not unlike those here at home. The surface is cold, but at times no colder than Earth's polar regions."

"There is water in the clouds and polar ice caps, and a day is only slightly longer than Earth's 24 hours. Every day is sunny (well, except during major dust storms), with pale rose-colored skies instead of the Moon's harsh black," he says.

Basically, life could survive on Mars but we couldn't survive on, say, Venus, the other nearest planet to Earth. Even though Venus has both an atmosphere and is about the same size as Earth, the air is toxic and the pressure at the surface is such that we'd be crushed, a fate met by some early Russian robotic explorers. Oh, and it's hot enough to melt lead on the surface.

Mars could be our next home. And it's important to us to find out as much as we can about it, not just to further our knowledge of the formation of our solar system and our own planet, but to prepare ourselves to become a multi-planet species, as SpaceX's Elon Musk has hoped for aloud, in interviews.

Mary Roach concludes, "...Mars is close enough to feel reachable, yet far enough away to seem utterly foreign and exotic and mysterious."