NASA Scientists Gather To Ponder Life Beyond Earth

NASA Scientists Gather To Ponder Life Beyond Earth

Jun 30


By Lisa M. Krieger
Mercury News
June 23, 2012

Original Link

We may not be alone.

But our cosmic companions might be moist creatures in watery worlds — lacking, of course, E.T.’s impulse, or ability, to phone home.

The growing evidence of wet planets — and its implications in our search for extraterrestrial life — is among the marvels shared this weekend at a Santa Clara gathering of astronomers, astronauts and science fiction fans.

The theme of the three-day SETIcon event: the exploration of universe and the quest to find life beyond Earth.

Scientists agreed that the neighborhood is looking a lot friendlier.

What began as a trickle of new planet discoveries a decade ago has turned into a torrent — and not all places are rocky, gaseous or just plain weird.

Of the 3,000 or so candidate planets found so far by Kepler — a NASA mission designed to find Earth-size planets around other stars — several hundred of them share one special characteristic: a density of nearly 1 gram per cubic centimeter.
That’s the density of water.

And, it could be prime real estate, said longtime planet hunter Geoff Marcy of University of California-Berkeley, speculating that these planets are composed of 30 to 70 percent water. “They’re not pure rock,” he said. “They’re not pure gas. These are planets that are composed almost certainly of water.”

In the past year, there’s been much hullabaloo about the search for a so-called “Goldilocks” planet that is Earth-like in its orbit or diameter.

But the prospect of water is equally profound, Marcy said.

That’s because water is the key solvent of biochemical reactions. In its rich cocktail of oxygen and hydrogen molecules, carbon can break apart and re-assemble into many forms. Maybe, for instance, amino acids. Or proteins. Or even DNA, the blueprint of life.

In this wet petri dish, perhaps exists a recipe for a creature that shares our passion for baseball, barbecue and bad television.

If planetary water is liquid — not ice or gas — “there is real hope that the planet out there will develop replicating molecules like DNA,” said Marcy.

Then what? “Those replicating molecules will compete for energy and resources,” he said. “And eventually that competition will lead to surviving molecules that outcompete others — and through Darwinian evolution, the development of a lipid-based cell membrane.”

“And voila!” he said. “The first signs of life.”

Predicted Seth Shostak, senior astronomer at the SETI Institute, sponsoring the event: “Waterworld didn’t turn out so well for Kevin Costner…But they may hold many more prospects of intelligent life.”

Planets are as common as a cheap hotel, scientists say. Here’s the math: If each star has an average of five planets — a reasonable guess, based on Kepler and other detection tools, scientists said — and our galaxy holds 200 billion stars, perhaps as many as a trillion planets are out there, awaiting discovery.

Even comedian Woody Allen once asserted: “There is no question that there is an unseen world. The problem is how is it from Midtown, and how late is it open?”

But here things get tricker.

Many of these newly-found planets are hostile places. Some circle too close to their star, and get blowtorched. Others circle too far away, so are very chilly places. A few don’t seem to circle at all, but have wacky, chaotic and tilted orbits. They yank at each other and are eventually flung out of their star system, as if from a slingshot, the scientists noted.

The most unlucky planets aren’t even connected to a star rather soar through space, untethered by gravity.

Still, even if just .01 percent of a trillion planets are wet and inviting, life might have a chance.

But what matters to SETI is not just life — but intelligent life. Or more specifically: life with tools.

In a wet world, techologies like phones, computers and rocketships are tough to construct, Marcy said. Even a very smart creature, surrounded by the entire periodic table, can’t do much with flippers and fins.

“You need metallurgy to develop electronics,” agreed Shostak.

And carting us light years into deep space to find them requires technology akin to wormhole rockets or matter-antimatter engines, the standard transports of science fiction, according to Shostak.

Meanwhile, there are other big efforts to unpack the composition of the universe.

UC-Berkeley astronmer Alex Filippenko and Bill Nye listed just a few remaining Big Questions:

• How can we detect gravitational waves?

• What gave rise to the universe — why was there a “Big Bang?”

• Why, despite gravity, is the Big Bang accelerating, instead of slowing down?

• Are there multiple universes?

• What is dark matter, which accounts for one-quarter of our universe — and can we directly detect it?

• What are the characteristics of dark energy, which accounts for almost three-quarters of the universe?

• What triggers the spark of life?

And, while we’re deep in thought: How does the brain work?

“Discoveries are being made all the time,” said Filippenko. “But there’s a whole bunch more that is left to be discovered.”


1 comment

  1. Simon Limbrick

    Not too long ago, right here on ‘Pulse’, it was asserted, that the universe may, in fact, be static. It was something to do with the speed of light, which travels at 186000 miles per second. By the time that light is detected on earth, say, it would give the appearance that the universe is still expanding.
    Given that, what do the experts really think?

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.