Earth Organisms That Can Survive Space
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Earth Organisms That Can Survive Space

On this channel I often talk about the possibility
of alien life. But I don’t really draw much of a distinction
between levels of life as far as discovering it goes, I’d be just as happy to detect
alien microbial life as I would be in discovering a full-fledged civilization. In, other words, I’ll take anything I can
get that confirms life in the universe independent of our planet. And, while I think intelligent life and civilizations
are probably rare, one aspect of life on earth gives me confidence that we are probably going
to find no shortage of simple, or even moderately complex life in the universe. It’s the sheer resilience of some species
of earth life, so much so that a handful of species can withstand the rigors of space. Other than the obvious lack of atmosphere,
one major threat to life that space poses is ionizing radiation. Exposure to this radiation is measured in
units called grays, and a mere 5 grays is enough to kill a human being, and anything
above 8 is certain death for most life on earth. There are only a few species of animal that
can stand a bit more, such as the German cockroach, which I suppose unsurprisingly can handle
up to 64 grays and also the resilient fruit fly which can take ten times that. Most of the microbes also have problems with
radiation, e. coli can only handle about 60 grays before it starts dying. But there are a few organisms on earth that
not only can withstand radiation to truly amazing levels, but can withstand the vacuum
of space so much so that we may some day find them living on some of the other bodies in
the solar system, and they also may be among the last living organisms on this planet when
the sun finally destroys it. The first of these is actually a family of
animals rather than a microbe, albeit a very tiny animal. It’s the famous tardigrade, a truly amazing
group of species that can go 30 years without eating, live for over 60 and survive a whopping
5,000 grays of radiation. They can withstand temperatures near absolute
zero to above the boiling point of water. And they are found in all environments on
planet earth and can even survive the dryness of space for a decade in a sort of dried up
suspended animation that ends once they are returned to water. In one case, a tardigrade that had been bone
dry for over 100 years was reanimated, sort of. It moved a leg, though no one is really sure
if that qualifies as being brought back to life. Regardless, that particular tardigrade might
not make the best material for a Frankensteinesque reanimation story. Tardigrades can even survive astrophysical
phenomena, and in fact have survived all of Earth’s mass extinctions that have occurred
since they first evolved. In a study done by David Sloan and Raphael
Batista, link in the description below, they took a look at the threats that face earth
that can cause mass extinctions of most life on earth and found that gamma ray bursts,
nearby supernovas and even asteroids, all fall short in their ability to cause the extinction
of the tardigrade. Only the events surrounding the evolution
of the sun will do it, though even then if they’ve colonized other places in the solar
system, they may continue to persist there. But even the tardigrade has its limits. It can’t really be classed as an extremophile
like some of the microbes because while it is incredibly resilient, it’s not really
designed for the harsh conditions that it can withstand. When dried up or frozen, they can’t reproduce
or do what tardigrades in normal environments do. And that brings us to something else entirely. That’s the lichens, some of which seem to
be radioresistant. Jean-Pierre de Vera and colleagues showed
that certain types of lichens, protected by niche environments could survive, photosynthesize
and grow on Mars. Add that with research done on the international
space station where certain species of lichens survived up to 18 months in the naked conditions
of space, and you have a possible scenario of earth lichens colonizing Mars through panspermia. But now we get to some organisms where radioresistance
reaches ridiculous heights. The first is called Deinococcus Radiodurans,
and like the tardigrade can survive multiple different types of adverse conditions, including
very high ionizing radiation three times that of the tardigrade at 15,000 grays. Remember, 5 grays kills a human, and 60 kills
e. coli. D. Radiodurans was actually discovered because
of its radioresistence. In 1956, Arthur Anderson was experimenting
with sterilizing canned food and while expecting to completely sterilize a sample with very
high radiation, he found that he did not due to this bacterium and his sample spoiled. The reason for this bacterium’s resistance
is that it can rapidly repair its own DNA on an order that almost every other organism
on earth cannot. This has led some researchers in the past
to wonder if this organism is even from earth. While the ability to dry out or go without
food is useful, there’s no really good reason for an organism to evolve such resistance
to radiation in earth’s low radiation environment. That opened up the notion that it might have
evolved on Mars early in life’s history in the solar system and was transported here
via panspermia, or alternatively perhaps it spent some part of its evolutionary history
in space. This has been largely discounted however because
as resilient as D. Radiodurans is, it bears much genetically in common with the rest of
life on earth. Work done by Valerie Mattimore of Louisiana
State Universe showed that the radioresistence is more likely to be a happy evolutionary
accident brought on by evolving an ability to completely dry out. The radio resistance was merely a chance side
effect of that. Or maybe not. The most radiation resistant organism found
on earth is a relative newcomer to science, discovered only in 2003. Named Thermococcus gammatolerans, this organism
is a mystery. It’s very different from D. Radiodurans
in that it belongs to the archea rather than the bacteria. And it likes deep ocean hydrothermal vents
where things don’t usually dry out. While it doesn’t seem to be well-suited
for the rigors of space, this organism can handle radiation like nothing else on earth. It can sustain a mind-boggling 30,000 gray
dose of gamma rays and no one knows why. Thanks for listening! I am futurist and science fiction author John
Michael Godier currently wondering if there are any dormant tardigrades in the room, I’m
surrounded! and be sure to check out my books at your favorite online book retailer and
subscribe to my channel for regular, in-depth explorations into the interesting, weird and
unknown aspects of this amazing universe in which we live.

27 thoughts on “Earth Organisms That Can Survive Space

  1. Yay conan the bacterium. Great video.
    Any thoughts on how this effect the odds of evolving more complex organisms near red dwarfs? I keep seeing claims that the x-rays emissions would limit the possibility of life in the habitable zone. Does the resistance to radiation make the tardigrade less likely to mutate?

  2. with that kinda gamma ray tolerance, can't believe they couldn't work in the latin-esque translation of "the hulk"

  3. You left out the fungus that grows in the ruins of chernobyl where it photosynthesises using melanin and gamma rays, or x rays…

  4. never heard much from the organisms found on the ISS's solar panels.
    the Russian guys said their cleaning rags all had some kind of algae-like stuff.
    Was that discounted, or was there ever any follow up?

  5. Fairly obvious observation, but if life starts very infrequently within a galaxy and is transported on comets/meteorites to so the seeds on many planets around many suns, then we should expect any traces of life on Mars or atmosphere of Venus, moons of Jupiter/Saturn to have a familiar double helix DNA structure (at least in our galaxy).

  6. That final microbe you mentioned, could it be an candidate for something that could have seeded life on Earth or is it still to complex to be among the first life? The presence of pre-cellular self replicating molecules like viroids seems to point toward life on Earth coming from something pre-cellular in my mind.

  7. DNA can be damaged by things other than radiation, heat and chemicals for instance. An organism can evolve the ability to quickly repair DNA damage caused by these hazards, and it would automatically be able to repair damage caused by radiation as well, even though it was never exposed to that particular hazard.

  8. If panspermia exists, why wouldn't a small portion of a biosphere still retain the traits that allowed it to make the transit in the first place? And as time went on, these remnant species would accumulate to some extant. If the universe is 13.7 (or whatever) billion years in age, how many of these transits should we expect to have occurred by now?

  9. wouldnt it be likely for all life anywhere to have DNA? theres no other chemical structure that can do similar things

  10. Awesome channel! I saw a comment you placed on one of Isaac Arthur videos that led me to check you out. You now have a new subscriber. Keep the excellent videos coming.

  11. Thank you John for another truly fascinating video. This channel is highly underrated. You would be no. 1 on my list but you have to share that spot with Isaac Arthur and Curious Droid, sorry.

  12. Ha! I gotcha some plants that will live on Mars: star thistle, burr clover and crab grass. No, not kidding. Give star thistle a try until you've gene modified cactus. Yup, cactus would take OVER Mars.

  13. Every time I watch one of your videos, I get so interested that when it ends, I'm like "No, keep going! This is getting good"!

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