Alien Invader!

Imagine yourself on the surface of Mars. The temperature is a balmy zero degrees Fahrenheit. The pink, nearly cloudless Martian sky surrounds a tiny but blindingly bright Sun, shining its feeble light on the frigid surface. In other words, it’s a beautiful day on the Red Planet.

Suddenly the sky opens up in a fiery and terrifying display. What can only be described as a creature from another world begins a rapid descent to the Martian surface. In the space of seven minutes, what was a speck of fire in the sky becomes an enormous robotic vehicle firmly planted on the surface of Mars. It promises quite a show.

First a parachute catches as much of the thin Martian air as it can, slowing the body of the craft down from a blistering 900 mph to a still-deadly 180 mph.

The parachute flies away and rockets fire beneath the falling body, slowing its descent further until, at only 66 feet above the surface, the creation hovers in mid-Martian air, balanced over the rocky, uneven surface below.

Then the strangest thing of all happens. What was one object becomes two, as the underbelly of the beast drops down to the surface on a set of cables known as a sky crane. Over the next minute, the lower body descends while the upper craft hovers around 66 feet above the surface. Finally, as the lower craft bites into the Martian dust, the cables break away and the upper craft disappears over the far horizon, never to be heard from again.

his is the strange scene NASA hopes to create in the wee morning hours of August 6, 2012 (COSI time). If all goes well, the Curiosity Rover will awaken from a long slumber in the Gale Crater near the Martian equator, and thereafter begin exploring what could be the most interesting landing site we’ve ever reached on the Red Planet.

For most of the history of our species, Mars was but a tiny red-orange dot in a starry night sky. But for us, for we humans lucky enough to live in the first years of the 21st century, Mars is a place, a world, a new land we have just begun to explore with our innovation, or ingenuity, and our curiosity.

The Rover itself is in many ways the most complex object ever to travel to Mars. The size of a small SUV, the Curiosity Rover is powered by radioactive decay and carries ten precision scientific instruments. Among these instruments is a robotic arm that will drill into Martian rocks, gather soil samples, and deliver those samples to instruments within. Curiosity will be the closest thing we’ve ever had to a working geologist on the surface of another planet.

While Curiosity itself is unlikely to detect life, and in fact the instruments aren’t designed for such a detection, it will tell us whether or not the surface of Mars could ever have provided a suitable habitat for living things. For an entire Martian year (around two Earth years), Curiosity will roam the area in and around Gale Crater, helping scientists back on Earth understand the past, present, and future of our neighbor in space.

But why do we care? So what if once, long ago, Mars was home to microbes? Here’s what. If we ever learn that Mars harbored life, then there are three possibilities:

• Earth life migrated to Mars through space. While possible, this is unlikely, as it is difficult for rocks blown off Earth (perhaps by meteor impacts) to reach Mars.
• Mars life migrated to Earth. This is actually much more likely than the former scenario, as it is much easier for rocks to be blasted off Mars (because of its lower gravity), and also more likely that such rocks might one day fall to Earth. If this scenario is true, then we are all Martians! But what if we find that...
• Life arose independently on Mars and Earth. This third is the most exciting scenario of all. For if so, then the universe must be teeming with life. One instance of life (on Earth) might be a fluke, not repeated in a billion, or even a hundred billion, worlds. But two examples of life practically side-by-side in the same solar system would indicate that life must be widespread throughout the cosmos.
• But we must also consider possibility 4. Perhaps life never developed on Mars at all. Perhaps life is more delicate than our science currently suggests. Perhaps our Earth really is unique. This fact might remind us all just how precious life really is, and how worthy of celebration.

The greatest thing about science is that someday (maybe someday soon) we will know. With Curiosity, we will discover secrets about Mars we never dreamt of before, and when we look up on a starry night and see a red-orange dot in the sky, we’ll know that dot is a place, a place we humans know a little better now, thanks to a rover with a name befitting the humans who sent it there. Good luck, Curiosity!