Washington Post article on astrobiology and the search for extrasolar planets, plus the cloudtops of Venus

Sunday, July 20, 2008


There might be life up here in the cloudtops too. Why not send a solar flyer?

There was quite the detailed article today in the Washington Post about astrobiology and the search for extrasolar planets, of which 307 have already been found. First it touches on the fact that the discovery of Earth-like planets and life, and that we're going to have to start to think about the effect it will have on society as a whole once that happens (probably within the next three to five years for other Earth-like planets, who knows how much longer for the actual discovery of life or a prime location for life):
The confidence that alien life will ultimately be found is strong enough to have kindled formal discussions among scientists, philosophers, theologians and others about the implications that such a find would have for humanity's view of itself, and how to prepare the public for the news, should it come.

"There's been a fundamental shift in the thinking of the scientific community on the question of life-forms beyond Earth," Pratt said.

Edward J. Weiler, one of the founders of NASA's astrobiology program and now chief of the agency's science division, goes even further.

"We now know the number of stars in the universe is something like 1 followed by 23 zeros," he said. "Given that number, how arrogant to think ours is the only sun with a planet that supports life, and that it's in the only solar system with intelligent life."
And on the growth of astrobiology:

Although humans have speculated for centuries about the possibility of extraterrestrial life, astrobiology began as a formal NASA program only in the mid-1990s, created in the excitement that followed the discovery of a meteorite from Mars that was initially thought to contain fossils or other evidence of microscopic organisms (a conclusion now generally rejected). The field has nonetheless grown quickly. More than 700 scientists and graduate students -- including molecular biologists, chemists, planetary scientists and cosmologists -- showed up at a NASA-sponsored astrobiology conference in California this past spring.

Many schools have growing astrobiology programs, and planet-hunter Paul Butler often travels from his base at the Carnegie Institution in the District to Chile, Hawaii and Australia to work with other astronomers at big telescopes. He estimates that 1,000 to 2,000 scientists now work in the field.

Then a bit more on future projects:
Much more is on the way. NASA will launch the Kepler probe next year, and its central goal will be to identify Earth-like, and possibly habitable, planets around distant stars. Japanese astronomers plan to band together to observe one star in great detail because of hints that it could have an orbiting planet with life. And preliminary work is underway for joint NASA-European Space Agency probes of Europa and Titan, moons of Jupiter and Saturn with conditions that might support life.
As far as I can tell, the star that Japanese astronomers will be concentrating on hasn't been decided yet. Here's an article on that subject from last month.

One part of the article is a bit odd though:
Lord Martin Rees, England's Astronomer Royal made that argument as the keynote speaker at NASA's spring astrobiology conference -- saying that life could not exist on Earth or anywhere else if the basic physical dynamics of the universe were not almost precisely what they are. Slight changes in the strength of the electrical force that holds atoms together, of the pull of gravity, or of the total mass of the universe would have made it difficult for stars to form and create the heavy elements essential for life, and impossible for them to remain active long enough to support the process of evolution.

Many religious thinkers see this fine-tuning as an argument for the existence of a creator, but Rees and other cosmologists offer a different explanation: that our universe is but one in a world of multiple (or infinite) universes. However it came into being, Rees argued, our universe is inherently life-supporting, and there is no reason to believe that that potential has been realized only on Earth.
Why? Because the argument for the existence of a creator isn't based on the idea that there is a limited amount to what can be created (a single universe), so the two sides written about here are pretty much talking about different things.

Oh, and it also addresses the clouds high in the atmosphere of Venus, which is a place that could have life that is almost never talked about even though it's the closest place to us besides the Moon:
"The Limits of Organic Life in Planetary Systems" report -- also known simply as "Weird Life" -- concluded: "The likelihood of encountering some form of life in subsurface Mars and sub-ice Europa appears high. . . . The committee sees no reason to exclude the possibility of life in environments as diverse as the aerosols above Venus and the water-ammonia [mixture] of Titan."
I've always found it a bit odd that we still haven't put the effort in to take a much more detailed look at the clouds of Venus through a solar flier, as has been proposed by Geoffrey A. Landis:
But the planet's dense atmosphere is ideal for a flying craft. A wing's lift depends directly on the density of the atmosphere and the atmospheric pressure on Venus is about 90 times that of Earth. After being released by an orbiter, the craft's origami-like wings would unfurl from an "aeroshell" (see Graphic). Solar panels on the craft's surface could absorb large amounts of the intense solar energy, powering motors to allow the craft to fly continuously. And the planet's slow rotation, with one day and night on Venus taking 117 Earth days, means a solar flyer could stay on the daylight side indefinitely.
To summarize:
  • The second-closest location to Earth besides the Moon.
  • 24 hours of solar power, all the time. No exceptions.
  • Terrestrial temperatures and high air pressure to make it extremely easy to fly.
  • Could harbour life.
So why haven't we sent a solar flyer to Venus yet?


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