Extrasolar Planet Could Harbor Life 308
BlueMorpho writes with a link to a Space.com article about a recently discovered extrasolar planet that may be able to harbor 'life as we know it.' Orbiting around the star Gliese 581 is a small rocky ball that might have the same liquid ocean and drifting continent configuration we're familiar with. The find may be unique in all of space exploration as this planet appears to be within a habitable band of temperatures for life, and is categorically not a gas giant. "The bottom line is exciting ...The conditions for life could be there, but is life itself? As yet, there's no way to know unless the planet has spawned beings that are at least as clever as we are. As part of the SETI Institute's Project Phoenix, we twice aimed large antennas in the direction of Gliese 581, hoping to pick up a signal that would bespeak technology ... Neither search turned up a signal."
Re:Might be hell to live on... (Score:4, Informative)
Re:Space/Genetic Exploration (Score:3, Informative)
Re:Space/Genetic Exploration (Score:5, Informative)
Try and imagine dutch elm disease making the transition from trees to humans. Then remember that both host organisms are terrestrial - we're more closely related to trees than we would be to any alien. It's not totally impossible that some alien bacteria could, by some chance, find the human body hospitable (or vice versa), but it isn't very probable.
Plus, the human immune system has a habit of attacking anything remotely foreign. That's why you get problems like allergies and organ rejection. If an alien organism is enough like us to pose an infection risk, then it's also most likely similar enough to trigger an immune response. And the diseases that we face today have had millions of years of evolution to prepare them for our immune system, whereas anything alien has not. So even if life elsewhere is very much like life here, it'll have the same catching up to do that we will. Admittedly pathogens evolve faster than their hosts, but then again these hosts have medical technology to make up the difference.
Gliese 581 is an M class star this is bad for life (Score:2, Informative)
http://en.wikipedia.org/wiki/M_dwarf#Habitability [wikipedia.org]
Re:Space/Genetic Exploration (Score:4, Informative)
1. Highly infectious diseases behave that way because they jump from a species in which it has coevolved (HCV in humans, Influenza in birds, various other diseases in pigs, rats, insects, etc), and so become not-terribly-pathogenic and suddenly entered a situation where it can jump species to another host. The extreme death rate of these diseases is a direct consequence of the fact that they DIDN'T evolve in the presence of humans, and that the new host behaves in an entirely unfamiliar manner to the foreign viral strain. Killing every organism it comes across is a horrible way for a virus to survive - the ideal is to achieve a minimal killing rate such that it becomes endemic to the population, with only a small proportion falling ill and dying. As such, our hypothetical alien virus has the potential to behave in this manner, provided the alien host is biochemically similar to us in one or more of the modes of entry for the viral strain. Admittedly, this only gives the potential for a mutant strain that could mess you up, but it's the same idea as Influenza - most truly common strains can't hurt you, but repeated contact with it in close quarters can give rise to an infectious system. Now, the true argument here is that it's unlikely that these hypothetical alien species we run into will have similar cell-surface proteins or modes of entry into the body - but simply arguing that a virus cannot infect a species it's never seen is a naive and deceptive idea. The far greater danger is...
2. Infectious microbes. The alien equivalent of bacteria, fungus, protozoa, worms, etc. It is quite likely that we will encounter a species which benefits from growing in a human-like environment, most likely some kind of warm, damp tissue bed. Find a rapidly growing strain of alien microbe which digests its food externally, mix well with a human mucus lining, and you very rapidly have the potential for a flesh eating species. Equally likely is that one of the common hormones fed out into the air by alien critters (think of the compounds produced by plants et al for communication) behaves as a carcinogen to the naive human metabolism, or acts as some kind of hormone mimic. Industry produces such compounds all the time, not to mention legitimate toxins on Earth - there's no way of saying that the air on a warm spring's day on an alien world wouldn't be lethal to us due to immediate and violent immune responses to the foreign contaminants. There are many possibilities about what alien organisms might do to us, and it's silly to think that just because we've never seen it, it won't cause some kind of mass physiological response.
Re:Needless hype: good publicity or bad conditioni (Score:3, Informative)
Look at our own solar system. Mars and Venus and a whole slew of gas giant moons have atmospheres. Given the gravity and energy input from it's star, you really have to stand this on it's head. You'd have to justify why it wouldn't have an atmosphere.