Greippi Posted August 24, 2010 Posted August 24, 2010 In short, a rock from a cliff in Devon was sent 300km high, exposed to the conditions of space, and then brought back down to Earth. It was found that one species had survived the trip - a photosynthetic cyanobactierium. Isolation of Novel Extreme-Tolerant Cyanobacteria from a Rock-Dwelling Microbial Community by Using Exposure to Low Earth Orbit
Greippi Posted August 24, 2010 Author Posted August 24, 2010 Shh, it needed a thrilling title to lure people in.
John Cuthber Posted August 28, 2010 Posted August 28, 2010 If I was as easy to please as a bacterium then I too could use a rock as a spaceship (for a short journey).
Mr Skeptic Posted August 28, 2010 Posted August 28, 2010 If I was as easy to please as a bacterium then I too could use a rock as a spaceship (for a short journey). I travel through space on a really BIG rock. 1
PhDwannabe Posted August 28, 2010 Posted August 28, 2010 I travel through space on a really BIG rock. HENRY: [demonstrating with rocks] See, this is us and we’re traveling AROUNNND the sun. That’s a 1.3 million mile trip every year! You might say that each and every one of us is a crew member here on... Spaceship Earth. CAMPER: When will we say that? HENRY: Any time. Dinner. Literally any time.
CaptainPanic Posted September 6, 2010 Posted September 6, 2010 The next step should be to see if bacteria can survive entry into the atmosphere and crashing into the surface of the earth.
leveni Posted September 8, 2010 Posted September 8, 2010 The next step should be to see if bacteria can survive entry into the atmosphere and crashing into the surface of the earth. I'm assuming you mean the bacteria would have to be inside the meteor in order to survive. The next question is how big would the meteor have to be for the bacteria to survive. What's the maximum temperature becteria can survive in?
CaptainPanic Posted September 8, 2010 Posted September 8, 2010 I'm assuming you mean the bacteria would have to be inside the meteor in order to survive. The next question is how big would the meteor have to be for the bacteria to survive. What's the maximum temperature becteria can survive in? Let's find out? Exactly! And let's also find out what type of meteorite is the best. I would assume a rather porous structure because it will have a poor heat transfer coefficient, which can perhaps keep its core cool enough during entry into the atmosphere. These are really experiments that need to be done in real... I know of no labs where we would be able to generate the ridiculous conditions that the meteorite will find itself in: traveling about 10 km/s in a very thin atmosphere, which rapidly gets denser and also rapidly slows down the meteorite. The exhaust of a rocket engine might come closest to the conditions. The entry will need to dissipate a massive amount of energy: 1 kg meteor, travelling at 10 km/s has a kinetic energy of E = 0.5*m*v2 = 50 MJ. If the entire rock (assume a Cp value of 1 kJ/kgK) heats up, the resulting temperature is 50000 degrees... But, there are many reasons why it will never reach that temperature: 1. It also heats up the atmosphere, not just the meteorite itself. 2. Ice present will quickly melt, heat up further and evaporate. 3. Upon impact, a crater is formed. That means that kinetic energy is transferred from the meteorite onto the soil of the earth. The question is, whether the inside of the meteorite will actually heat up to a temperature so high that microorganisms die. I'm not in the mood to do a calculation now (because heat transfer in non-continuous situations is really tricky ).
ccdan Posted September 12, 2010 Posted September 12, 2010 there are some things that are a bit closer to bugs than bacteria, which do survive in space: Tardigrades (commonly known as water bears or moss piglets)[3] form the phylum Tardigrada, part of the superphylum Ecdysozoa. They are microscopic, water-dwelling, segmented animals with eight legs. Tardigrades were first described by Johann August Ephraim Goeze in 1773 (kleiner Wasserbär = little water bear). The name Tardigrada means "slow walker" and was given by Lazzaro Spallanzani in 1777. The name water bear comes from the way they walk, reminiscent of a bear's gait. The biggest adults may reach a body length of 1.5 mm, the smallest below 0.1 mm. Tardigrades are polyextremophiles and are able to survive in extreme environments that would kill almost any other animal. Some can survive temperatures of -273°C (-460 °F), close to absolute zero,[5] temperatures as high as 151 °C (303 °F), 1,000 times more radiation than other animals,[6] and almost a decade without water.[7] In September 2007, tardigrades were taken into low Earth orbit on the FOTON-M3 mission and for 10 days were exposed to the vacuum of space. After they were returned to Earth, it was discovered that many of them survived and laid eggs that hatched normally, making these the only animals known to be able to survive the vacuum of space.[8] http://en.wikipedia.org/wiki/Tardigrade
insane_alien Posted September 12, 2010 Posted September 12, 2010 Captain, you forgot sublimation of the meteorite itself. personally, I think that the size of a meteorite will play a big role. It needs to be big enough to get through the atmosphere without burning up completely yet it would need to be small enough to lose the majority of its kinetic energy to the upper atmosphere and then hit the surface at its terminal velocity. If it's too big, ie, big enough to cause disintegration and deformation of the impactor, it is likely that it got too hot during impact with the ground for an organism to survive. If it formed a fireball on impact then definitely nothing survived. http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?bibcode=1934PA.....42...59W&db_key=AST&page_ind=0&data_type=GIF&type=SCREEN_VIEW&classic=YES < this link is useful basically ,you don't want to be looking at iron meteorites as those will heat up all the way through during re-entry and hence kill anything living on it. stony ones are better as the have a lower conductivity and it will mainly be the outer layers that get hot while the inside could remain much colder carbonaceous meteorites would seem the most likley to me as they contain potential food sources(not only for the origin and transport of the organism, but for when it is 'activated' on arrival at a habitable destination. unless there are some yummy amino acids and sugars on the stony meteorite as well as a bit of water(although that could potentially be supplied with rain or ocean) then the poor bacteria might just die of starvation
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