Beyond Nature

Have you ever read any of Asimov's novels?? (The Robot series, The Robots and Aliens) . Ever wondered if there is any possibility in the near future that a person can actually get to another planet and if not investigate a case like Elijah, can at least explore the place and can one day share a meal with our counterparts! Is this possible?? Is there any life beyond the Planet Earth?? Is there a safe neighborhood out in the universe except Earth?? I feel that these questions are quite common , the very mention of the Alien and ET raises the eyebrows.

Imagine an Alien or lemme call it the 'ET' stepping down a Flying Saucer or UFO(Just as in the film ET) and walking straight to you..!!!! This very imagination is quite amazing, electrifying, terrifying or adventurous may be .. isn't it?? I do find myself lost in these thoughts sometimes when Iam alone starring the Night Sky , by the way sky looks quite beautiful! I wonder how an encounter with the Alien turns out to be like.. Would he/she look just as we do? Do they possess the same technology or are they any advanced?? Are they friendly or will they harm us( Just like any Alien that has so far been portrayed in the films)?? Its just an unquenchable thirst of we humans that has been keeping us busy over centuries trying to find out the existence of an outer world.

These are the kinds of questions Ken Nealson struggles with. A geo-biologist at the University of Southern California, Nealson is heavily involved in devising strategies for searching for extraterrestrial life. And his number one goal is to free himself and his colleagues from the confines of their own preconceptions about life.

"It seems to me the worst people to look for life are biologists," Nealson, also a senior scientist at the NASA/Caltech Jet Propulsion Laboratory, says. "Because theyre so darned sure of what life is that if it happened to be different, theyd miss it." Nealson admits this point of view isnt very popular with his colleagues. "Oh, they love me," he laughs. "At least I'm a biologist saying it, so they cant just claim I'm some mad physicist whos trying to take their funding away."

As a cautionary tale, Nealson points to the only previous mission to look for life on another planet. In 1976 two Viking landers arrived on the Red Planet, each outfitted with a miniature biological laboratory. Scoops of Martian soil were fed into a series of experiments, where they were exposed to a puff of humidity, or a drop of water, or a nutrient broth. If any microbes were present, the Viking biologists hoped, the instruments would detect their metabolic processes.

But the experiments didn't discover microbes, and Nealson says thats because they were based on the characteristics of Earthly life. Thats something he wants to avoid on future missions: "Id like to be one of the chorus of voices saying, Dont do this again."

But that doesn't mean Nealson wants to avoid Mars far from it. If anything, Mars has become even more alluring since the Mars Global Surveyor probe found signs that liquid water has recently flowed on the planets surface and may still exist underground.

More than anything, Nealson wants to send a new life-detection mission to the Red Planet. "If I get one thing done before I retire," Nealson says, "it would be to have a mission that went to Mars, because its the one place we probably can go in my lifetime that would do a serious attempt at what I would call non-Earth-centric life detection."

If you call that living

Even our understanding of terrestrial life is changing. Recently, scientists discovered a thriving community of microbes deep in a hot spring in Idaho. These microbes, ancient relatives of bacteria called Archea, make energy by combining hydrogen from rocks with carbon dioxide, and exist completely apart from the Sun. And yet, they may be as numerous as living things on Earths surface, an entirely independent biosphere within the crust of our planet.

And some researchers have speculated that the same kind of life may exist in the crusts of other planets, provided there is enough geologic activity to supply the necessary hydrogen. But designing a space mission with probes to look for such life, many hundreds of feet down, is too ambitious in the near term. Even so, the find reinforces a watchword for life-hunters: Expect the unexpected.[more...]

Robots rules of order

There's another pitfall for life-hunters:The desire to find what they're after. In 1996 NASA scientists claimed to have found evidence for fossil microbes inside a meteorite from Mars. The claim was extremely controversial, and since then most researchers have come to believe the features in the Martian meteorite can be explained by non-biologic processes. Nealson says the NASA team was seduced by their own data.This wasn't a bunch of amateurs; these were good people. Anybody can be fooled by their data; Ive been fooled by mine in the past." But the seduction, Nealson notes, was understandable.

"Almost everything they found was consistent with life," he says. "And when you find enough things that are consistent with life, you start feeling that you've found life. But theres a big difference between five or six things being consistent with life and five or six things needing life to explain their existence. That to me is the big difference: Is there anything there that absolutely couldn't be there if there wasn't life?"[more...]

Europa ocean cruise

Planetary scientist Chris Chyba of the SETI Institute in Palo Alto, California is also anxious to see the search for life on Mars resume. But he’s also focused on another alluring target -- Jupiter's moon Europa. Images from the Galileo spacecraft, with other data, have shown that there is probably an ocean of liquid water beneath Europa’s icy crust. It’s not an easy place to explore: Europa is some 400 million miles from Earth, and it lies deep within Jupiter’s powerful radiation belts, which pose a hazard to any spacecraft.

But planners have envisioned a number of possible missions, including orbiters and landers, to explore Europa. Some have proposed an ambitious mission to melt through the ice and deploy a "cryobot" in the ocean to hunt for life. But Chyba says, "That kind of mission is extremely far in the future. Maybe it will be this century; I hope so. I think it's a very distant mission."
"You probably don't have to fly a cryobot to, in effect, access the ocean," Chyba says. "What you've got to do is go to a spot where it looks as though liquid water from the subsurface has reached the surface. And we can already identify areas like that on the surface of Europa."

Be like Earth

When it comes to life on other solar systems, the statistics seem promising.Four decades ago, Chyba's colleague Frank Drake authored a now-famous equation that judged the likelihood of extraterrestrial civilizations, or any kind of life, based on the number of habitable planets thought to be orbiting other stars. Back then, that number was pure conjecture. But now, after discovering several dozen extrasolar planets, astronomers are on the verge of learning whether other solar systems like ours are scarce or plentiful."

My prejudice is that we're going to discover that our solar system is neither rare nor typical," Chyba says. "But it doesn't really matter what I think is going to happen. We're actually going to know. Probably this decade, we're going to know."That's because of the upcoming Kepler mission, which will search for Earth-like planets around 100,000 stars beginning in 2006. "We're about to have catalogs of other solar systems, the way we have catalogs of stars [today]," Chyba says.

Whether any of these other solar systems are home to living things is something scientists hope to answer without leaving home. With powerful telescopes, perhaps including space-based arrays of instruments, it might be possible to detect the presence of atmospheric gases typical of life.

"I think it's going to prove very difficult to do in a way that seems convincing," Chyba said. "That doesn't mean we shouldn't be trying to do it."[more...]

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