Re: [meteorite-list] Did Life Arrive Before the Solar SystemEvenFormed?
Howdy Alright, I need to go point-by-point for this one... For the Surveyor 3 microbes: I've never heard the story of Pete Conrad actually seeing any microbes; are you sure about that? I know they brought back the camera and other parts and swabbed/cultured them, and were rewarded with a colony of streptococcus from the camera insulation. The reason that it was never hyped up, or even published officially as far as I know, is that it could be the result of airborne contamination -=after=- the camera was returned to Earth. The camera and other parts were not handled in a sterile fashion, and they shared the Apollo capsule with the three astronauts for several days on the way back to Earth. They were handled after landing as well, and basically there is no sure-fire proof that this very common airborne microbe did not settle on the camera afterwards or even result from a sneeze by one of the investigators. For the tardigrades: yes, they can withstand a lot. BUT, only after they have been induced into a spore-like state. They are not technically alive, but rather in a state of dessicated suspension. The same can be said for spores of many types of organisms. They are tougher than when they're actively metabolising, but they're still not bulletproof. I'm not familiar with the Mars Jars experiment, but keep in mind that we knew much less about the actual conditions on Mars in the 50's than we do today. I'd be interested in seeing a modern re-creation of that experiment. Bah humbug yet, MDF Hi, Just a sort of footnote to my previous post on this topic. I forgot the most obvious example of critters in space. On April 20, 1967, the Surveyor 3 spacecraft landed on the moon. Unknown to us, it was carrying some uninvited passengers. When Surveyor 3 was being prepared for launch, somebody apparently coughed on it, and a colony of a common bacteria, Streptococcus mitis, was established on a piece of foam insulation that covered one of Surveyor's circuit boards. The bacteria was discovered in 1969 when Apollo 12 astronauts Pete Conrad and Alan Bean visited the wreck of Surveyor and saw something odd growing on the insulation and brought back a piece of it. The bacteria had struggled along, multiplying and growing for a while before they went dormant and were freeze-dried. Once back on Earth, they were revived in a normal agar culture and started growing again, while waiting for their chance to get back into a warm wet human throat and give it a cough... For someone whose natural habitat was that warm wet human throat, I'd say they handled life in a vacuum with a temperature range of +300 degrees C. to -250 degrees C. every month pretty well. I also remember experiments done in the 1950's in which tiny creatures called Tardigrades (also known as water bears) were put into Mars Jars, meaning simulations of the Martian evironment kept at the correct Martian temperatures, pressures, atmospheres, near-waterlessness, and so forth. They thrived and multiplied (although more slowly than on Earth). Although Tardigrades are tiny (about 200 microns long!), they like us are complex multicellular organisms with feet, guts, heads, eyes, and lots of other movable parts. (Although, they don't have jaws because they have evolved a specialized spear mouth that doesn't need a jaw -- they don't bite; they stab!) I quote: Some tardigrades can survive in temperatures as low as minus 200 degrees Celsius (minus 328 F). Others can survive temperatures as high as 151 degrees C (304 F). Tardigrades can survive the process of freezing or thawing, as well as changes in salinity, extreme vacuum pressure conditions, and a lack of oxygen. Tardigrades also are resistant to levels of X-ray radiation that are hundreds of times more lethal to humans and other organisms. This resilience stems from the tardigrade's ability to survive without water. The quote is from NASA's ASTROBIOLOGY magazine, which had a nice article about the water bears (with pictures). They look more like Gummi Bears, with the same silly faces... http://www.astrobio.net/cgi-bin/h2p.cgi?sid=261ext=.pdf Now, what would happen if you snuck a tiny little capsule with about 100,000,000,000 Tardigrades onto the next Mars probe scheduled to land on the surface? Instant Martians? I love a good experiment... Sterling K. Webb -- Marc Fries Postdoctoral Research Associate Carnegie Institution of Washington Geophysical Laboratory 5251 Broad Branch Rd. NW Washington, DC 20015 PH: 202 478 7970 FAX: 202 478 8901 - I urge you to show your support to American servicemen and servicewomen currently serving in harm's way by donating items they personally request at: http://www.anysoldier.com (This is not an endorsement by the Geophysical Laboratory or the Carnegie Institution.) __ Meteorite-list mailing list
Re: [meteorite-list] Did Life Arrive Before the Solar SystemEvenFormed?
What's your idea of life's origin. Earth bound at the throat of an oceanic fumerole? Just wondering. Jerry - Original Message - From: Marc Fries [EMAIL PROTECTED] To: Meteorite Mailing List meteorite-list@meteoritecentral.com Sent: Wednesday, May 04, 2005 5:44 PM Subject: Re: [meteorite-list] Did Life Arrive Before the Solar SystemEvenFormed? Howdy I don't like panspermia; not even a little bit. It does nothing to answer the question of where and how life started in the universe. All it does is add a few million to billions of years of travel in the cold, dry, radiation-hard vacuum of space to the journey. That, plus you've got to crush/heat it in a violent, solar-system-ejecting imact and then crush/heat it again on the recieving end. Even if you shorten that journey to a trans-planetary scale you've still done nothing to answer any questions about how it originated, and you're still dealing with several physical processes that each alone have the power of sterilization. And at the end of all of THAT, you've still dropped any surviving (not bloody likely) microbes into a foreign environment that they're not adapted to! You can hang litho or nano or freakin' nuclear-powered or anything you want to onto the front of panspermia and it's still useless as a theory. How annoying that it still crops up from time to time... Bah humbug, MDF http://www.universetoday.com/am/publish/lithopanspermia.html Did Life Arrive Before the Solar System Even Formed? Written by Jeff Barbour Universe Today May 4, 2005 Summary - (May 4, 2005) The theory of panspermia proposes that life really gets around, jumping fron planet to planet - or even from star to star. Life might be everywhere! Assuming this is true, how do single-celled bacteria make the journey through the vacuum of space? Easy, they use chunks of rock as space ships, in a process called lithopanspermia. And now, researchers from Princeton and the University of Michigan think that life carrying rocks might have been right there at the beginning of our solar system, keeping their tiny astronauts safe and sound, frozen in statis until the planets formed and the right conditions let them thaw out, stretch their proteins, and begin a process leading from microbe to mankind. Full Story - Things seem to start simple then get more complex. Life is like that. And perhaps nowhere is this notion truer than when we investigate the origins of life. Did the earliest single cell life-forms coalesce from organic molecules here on Earth? Or is it possible that - like dandelions wafting spore above spring grass - cosmic winds carry living things from world to world later to take root and flourish? And if this is the case, how precisely does such a dia-spora occur? 450 years before the common era, Greek philosopher Anaxagoras of Ionia proposed that all living things sprung from certain ubiquitous seeds of life. Today's notion of such seeds is far more sophisticated than anything Anaxagoras could possibly envision - limited as he was to simple observations of living things such as budding plant flowering tree, crawling buzzing insect, loping animal or walking human; not too mention natural phenomena like sound, wind, rainbows, earthquakes, eclipses, Sun, and Moon. Surprisingly modern in thought, Anaxagoras could only guess as to the details... Some 2300 hundreds years later - during the 1830s - Swedish chemist Jöns Jackob Berzelius confirmed that carbon compounds were found in certain meteorites fallen from the heavens. Berzelius himself however, held that these carbonates were contaminates originating with the Earth itself - but his finding contributed to theories propounded by later thinkers including the physician H.E. Richter and physicist Lord Kelvin. Panspermia received its first real treatment by Hermann von Helmholtz in 1879, but it was another Swedish chemist - 1903 Nobel Prize winning Svante Arrhenius - who popularized the concept of life originating from space in 1908. Perhaps surprisingly, that theory was based on the notion that radiation pressure from the Sun - and other stars - blew microbes about like tiny solar sails - and not as the result of finding carbon compounds in stony meteorite. The theory that simple forms of life travel in ejecta from other worlds - embedded in rock blasted from planetary surfaces by the impact of large objects - is the basis for lithopanspermia. There are numerous advantages to this hypothesis - simple, hardy forms of life are often found in mineral deposits on Earth in forbidding locales. Worlds - such as our own or Mars - are occasionally blasted by asteroids and comets large enough to hurl rock at speeds exceeding escape velocities. Mineral in rocks can shield microbes from shock and radiation (associated with impact craters) as well as hard radiation from the Sun as stony meteors move through space. The hardiest forms of life also have the ability to survive in a cold vacuum by going into stasis - reducing
Re: [meteorite-list] Did Life Arrive Before the Solar SystemEvenFormed?
Superior fun read! Jerry - Original Message - From: Sterling K. Webb [EMAIL PROTECTED] To: Meteorite Mailing List meteorite-list@meteoritecentral.com; Marc Fries [EMAIL PROTECTED]; [EMAIL PROTECTED] Sent: Wednesday, May 04, 2005 9:58 PM Subject: Re: [meteorite-list] Did Life Arrive Before the Solar SystemEvenFormed? Hi, Humbug and All, Humbug right back. You'll notice the press release so politely mentions that quote previous studies have looked into the likelihood that life-bearing rocks (typically exceeding 10 kgm's in weight) play a role in the spread of life within isolated planetary systems and found the odds of both meteoroid and biological transfer are exceedingly low. unquote They are referring to what is (was?) considered the definite work on the subject by impact authority Jay Melosh: http://www.lpl.arizona.edu/~jmelosh/InterstellarPanspermia.pdf who basically said not in the lifetime of the galaxy or in other words, Humbug! Melosh's work was an impressive piece of computer simulations. The problem with computer simulations is that you have no idea if you're right or tip-toeing through the daisies without a reality check. At the time of its publication, I posted a fine cranky piece to the List, pointing out that AMOR radars all over the world (but particularly New Zealand with their lovely view of the South Pole) detect objects that have to have come from outside the solar system all the time. Granted, they are less than 1% of the tens of thousands detected per year, but that's still one hell of a lot of interstellar meteoroids! Yes, granted they are small grains, not 10 kilogram transports, but do you really think that bacteria chicken out and cancel their flight plans if the plane doesn't weigh at least 10 kilograms? You're not getting me up there in that thing -- why that rock doesn't weight one kilo much less ten! If there are frequent small interstellar particles, then less frequently there are larger ones, and even less frequently there are even larger ones, and so on. It's called the power law of mass distribution. And it means that all those computer simulations really were only a walk through the daisies... Extremophiles just love extremes. Radiodurans clogs up the core of nuclear reactors, basking without sun block or dark glasses in a flux that would kill you in five seconds or less. There are extremophiles that love the pressure miles into the Earth's mantle, extremophiles that smack their chops at the chance to dine on almost any toxic substance known, extremophiles that catch cold if they're not swimming around in 600-degree fluids. Anything or anywhere nasty, there's some little bug that loves it, needs it, and just can't live without it. Commonly, you might think nothing could survive so long or hard a journey. I point you to a simple example of survival by endurance: the common tick. Ticks are complex animal organisms just like we are, not hard durable one-cellers. But once a momma tick embeds her dormant offspring in the bark of a tree limb, the young tick will persist in a state indistinguishable from death for 10 years, 30 years, 50 years, 80 years (no one really knows how long), until a sweaty warm-blooded mammal walks under the tree and a few molecules of its pheromones waft up to the tree limb. In the 0.5 to 1.0 second that passes from the time your sweaty forehead moves under the tree limb and your scent starts up slowly toward the limb, the 50-year dead tick will detect those molecules from its burial site inside the tree bark, wake up from its death, get every organ pumped up and working, bore through the bark of the limb, and drop straight down with unerring aim onto the back of your neck or into your hair if he's fast enough, ready to start drinking your blood! If the tick misses you, it's dead. It won't get a second shot and hasn't the strength to try anything else. If you describe this strategy to most people without telling them it's the life of a tick, they will just shake their heads and say, Impossible. But, since there certainly seem to be more than enough ticks in this world, this impossible scenario must succeed. So, I figure that a living (though possibly dormant) cell riding in a dust mote that's zipping through the 3 K vacuum and dodging the rare UV photon and cosmic rays (even rarer), is a distinct biological option, no more amazing or unlikely than that tick. I see him now. He's drifting along, sound asleep in his recliner, and waiting for that soft landing in the atmosphere of a planet he can eat. Yum. Crunch. And before you know it, there's another blue world with a poisonous oxygen atmosphere... Since the Universe is almost exactly three times older than the solar system, this has likely been going on for a long, long time, and I figure the whole place is probably thoroughly infested with ubiquitous life, life, life. The dam things are everywhere
Re: [meteorite-list] Did Life Arrive Before the Solar SystemEvenFormed?
Hi, Just a sort of footnote to my previous post on this topic. I forgot the most obvious example of critters in space. On April 20, 1967, the Surveyor 3 spacecraft landed on the moon. Unknown to us, it was carrying some uninvited passengers. When Surveyor 3 was being prepared for launch, somebody apparently coughed on it, and a colony of a common bacteria, Streptococcus mitis, was established on a piece of foam insulation that covered one of Surveyor's circuit boards. The bacteria was discovered in 1969 when Apollo 12 astronauts Pete Conrad and Alan Bean visited the wreck of Surveyor and saw something odd growing on the insulation and brought back a piece of it. The bacteria had struggled along, multiplying and growing for a while before they went dormant and were freeze-dried. Once back on Earth, they were revived in a normal agar culture and started growing again, while waiting for their chance to get back into a warm wet human throat and give it a cough... For someone whose natural habitat was that warm wet human throat, I'd say they handled life in a vacuum with a temperature range of +300 degrees C. to -250 degrees C. every month pretty well. I also remember experiments done in the 1950's in which tiny creatures called Tardigrades (also known as water bears) were put into Mars Jars, meaning simulations of the Martian evironment kept at the correct Martian temperatures, pressures, atmospheres, near-waterlessness, and so forth. They thrived and multiplied (although more slowly than on Earth). Although Tardigrades are tiny (about 200 microns long!), they like us are complex multicellular organisms with feet, guts, heads, eyes, and lots of other movable parts. (Although, they don't have jaws because they have evolved a specialized spear mouth that doesn't need a jaw -- they don't bite; they stab!) I quote: Some tardigrades can survive in temperatures as low as minus 200 degrees Celsius (minus 328 F). Others can survive temperatures as high as 151 degrees C (304 F). Tardigrades can survive the process of freezing or thawing, as well as changes in salinity, extreme vacuum pressure conditions, and a lack of oxygen. Tardigrades also are resistant to levels of X-ray radiation that are hundreds of times more lethal to humans and other organisms. This resilience stems from the tardigrade's ability to survive without water. The quote is from NASA's ASTROBIOLOGY magazine, which had a nice article about the water bears (with pictures). They look more like Gummi Bears, with the same silly faces... http://www.astrobio.net/cgi-bin/h2p.cgi?sid=261ext=.pdf Now, what would happen if you snuck a tiny little capsule with about 100,000,000,000 Tardigrades onto the next Mars probe scheduled to land on the surface? Instant Martians? I love a good experiment... Sterling K. Webb __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
