Researchers from the University of Kent decided to answer the eternal question ...
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| One Small Step For A Tardigrade ... One Giant Step For Tardigrades? |
.... What punishment can a Tardigrades take?
Now I say the eternal question .... but of course not for most of us, who are probably thinking more along the lines 'Will normal life ever resume?' But hey ho, it takes all sorts, and if you a researcher, its been a long 16 months twiddling your thumbs.
Now, if you don't know it, Tardigrades are amongst the toughest little critters on earth, and are one of the only known organisms, that can possibly survive a trip to outer space. This means that they apparently could survive an interplanetary trip between planets, or even an interstellar trip between solar systems, on comets or asteroids. This fact has meant that there has been speculation that they (or a relative), may have seeded life on Earth in a theory known as Panspermia.
So, in order to see if it was possible, the researchers took 20 Tardigrades (volunteers only I hope), and put them into a state of suspended animation (aka hibernation), by freezing them, then placing the little chaps into water filled nylon cylinders, before firing the cylinders a great speeds at sand targets via a high powered light gas gun. The idea being to mimic the most likely arrival method for little space travellers to land on a planet.
Sadly for many of the brave space volunteers, it was found that any landing at greater than 900 metres per second was invariably fatal. This speed was just under the slowest typical speed of a meteorite hitting Earth, which is around 1,100 metres a second.
This is something of a blow for Panspermia theorists, as its now unlikely that Tardigrades or creatures like or related to them (although microbes can survive the landing), could have been responsible for any seeding of life on the early Earth (if that was how life developed after arriving here by that method). It was also something of a blow to the many Tardigrades who failed to survive the experiment!
But there is still hope for Panspermia theorists .... because there is another potential fellow tough microscopic space critter ... the bdelloid rotifer, not a name I was previously aware of, but a hardy litter critter just the same. It has been found to be able to be revived after laying frozen for over 24,000 years in the Siberian permafrost. Like the Tardigrades it to is also highly resistant to radiation, low oxygen and starvation.
They also have one big advantage in that they are self reproducing, as all individuals are female and produce fertilised eggs. The young are clones of the parent. So a trip across the solar system, and even interstellar trips would be a piece of cake .... as long as they can survive the cannonball run crash landings that the Tardigrades failed to do.
According to reports, Tardigrades are likely to be sent into space, as one way interstellar travellers from Earth on a Solar sail powered craft. They were taken aboard the international space station as a study subject, but the next aim is to send them in to interstellar space in their dehydrated, cryptobiotic form, and then we would remotely wake them up, with some water and study their revival.
ReplyDeleteThe experiment could be ready in around 20 years. In theory the Tardigrades could eventually land on another planet (they live around 60 years), but any fears of them 'polluting' another planet, or even starting life on a barren one, are minimal, because as this post has shown, they don't survive the high speed impacts. In any case, the spacecraft would be travelling so fast it would get vaporised instantly it hit anything, or burn up in an atmosphere.