Could we ACTUALLY grow potatoes on Mars? | OVERTHINKING The Martian

so you guys know that on this channel I love picking apart the real science from the fiction in my astrophysicist react series but you know there's a load of like sci-fi films and TV programs that I've already watched that I can't really react to like for example my absolute favorite the Martian so when I saw this question on Twitter the other day from Edward about whether it'd actually be possible to grow potatoes on Mars I knew I just had to dive into this and find all of the scientific research papers I could to answer this question and essentially do what I do best and overthink things that I see in films so as Mark Whitney so eloquently put it when I have the science the out of this so there's a few questions we can ask you first of all is it even possible to grow plants in Martian soil question two is human waste as a fertilizer a good idea in question three what are the practical problems for growing stuff on Mars like is lower gravity an issue for example so let's start with question one is it even possible to grow plants in the Martian soil now obviously no one has tried to actually grow plants on Mars yet but thanks to you know a lot of the Martian Rover missions like curiosity and perseverance we have a good idea of what the Martian soil is made of so much so that we can actually recreate that here on Earth either you know like artificially in a lab or we can find good analogs you know in certain places like deserts on Earth as well that are very similar to The Martian soil so we call this a martian analog soil or a martian stimulant soil and experiments have shown that loads of different types of potatoes are capable of being grown in Martian analog soil plus this paper from Vega veiling and collaborators actually showed that Martian analog soil retains water better than like their control sample using an earth soil in their experiment that also showed that crops like tomato wheat and crests could be grown in Martian analog soil similarly the food company Heinz did an experiment in conjunction with Andrew Palmer's group at Florida Tech showing how Tomatoes grew extremely well in Martian analog soil so much so that Heinz was able to make a bottle of Martian ketchup with the tomatoes that were grown which along with being one of the greatest PR stunts that I've ever seen was also some really good science as well you know maybe if Mark Watney had known how good a crop Tomatoes were to grow on Mars then you know maybe this would never have happened seven days since I ran out of ketchup so yes we do think it would be possible to grow crops on Mars and basically the hardier the plant the better if you want to do your own experiments either at home or in the classroom I found this great resource which was essentially a lesson plan for teachers outlining all the different experiments that you can do which I'll link in the video description down below if you're interested plus this website the Martian Gardener where you can buy Martian analog soil like this isn't sponsored or anything I just I just found them on my internet travels again I'll link it down below then question number two Mark Watney uses um human poop as a fertilizer for his potato crops is this ever a good idea now the reason you need a fertilizer to grow crops on Mars is you need to provide the plants with all of the you know essential nutrients and minerals that they need to grow now on Earth that naturally occurs in the soil a lot of it comes from you know bacteria just chomping up a load of the Dead plants the I've come to it before whatever plan is now growing there but obviously on Mars that doesn't exist now it turns out that pretty much all the nutrients and minerals that you do need for plants to grow already are naturally occurring in Martian soil except for nitrogen which rather annoyingly is perhaps the most essential mineral for plant growth any gardeners watching will know that plant feed you know is the classic NPK mix of nitrogen phosphorus and potassium so you need a source of nitrogen to grow plants on Mars and that could either be in the form of you know like a plant feed or a fertilizer now presumably despite being a botanist sent to Mars to do botany experiments Watney didn't have any plant feed on him or at least not enough plant feed and so we turned to the next best thing which was human waste as fertilizer now this would be a terrible idea to do on earth like do not grow plants months using human waste as a fertilizer because it contains pathogens that are incredibly harmful if you ingest it you know in a food that's been grown in a pathogen Rich environment especially when that waste comes from another person as well which he has to do he makes use of all the waste left behind by the crew but thankfully on Mars in the Martian atmosphere you've got Sub-Zero temperatures so you can just take human waste outside freeze dry it that kills off all of the harmful pathogens that it can be used as a safe fertilizer but this actually raises a really interesting question over whether we should actually send humans to Mars or not because inevitably you are going to contaminate the Martian surface you know with like bacteria and pathogens and things like that which is a really big deal if we're going to keep trying to answer the question of is there life on Mars you know that's what for example the perseverance Rover is currently trying to do a Mars by collect acting all of these Rock samples that are going to be returned to Earth so that we can test them for biosignatures known markers of life either current life or past life because if we ever did find evidence for life on Mars then the next big question is does it look similar to life on Earth and if it does you can say okay well does life of Mars and life on earth have a common origin of some form like for example asteroids and comets like bringing the ingredients of life to both the early Earth or to the early Mars or for example they only bring it to one planet but then an asteroid hit that planet and that sent off a load of debris which then also sent the ingredients for life or even life to the surface of Mars or vice versa like did life come from Mars first and did debris from Mars populate life on Earth or if it looks completely different to life on Earth then you know that life has started independently on the two planets and that would be incredibly cool but if you found this kind of evidence after we'd sent humans to Mars then there would always be this question of whether you'd actually detected Life on Mars or just contaminant from humans being there and present on the surface so I'll always be team Rovers and robots and little drone helicopters exploring the solar system and not sending humans to Mars just to prove that we can because it will interfere with all the science that we want to do instead and the third question what about the Practical challenges of growing stuff on Mars it's all very well and good doing all these experiments and Labs here on Earth with Martian analog soil but the conditions on Mars are always going to be so much different and harsher as well like for example the fact there's less incident sunlight on Mars just because it's further away from the Sun than Earth is so the sun's emitted light is spread over a greater area and so it doesn't get as bright on Mars the peak brightness that the sun gets in perfect conditions on Mars is about 44 less than here on Earth it's actually similar in brightness to what like Northern Canada Iceland Norway Etc you know on the edge of the Arctic Circle get in winter time in fact there's a greenhouse where they're growing plants in Martian analog soil in Northern Canada on Devon Island the Arthur Clark Mars Greenhouse it was built in 2002 to simulate the same light conditions as you would get on Mars okay so yeah we have a decent chance of recreating the same light conditions as we'd expect on Mars here on Earth but one thing we definitely can't recreate or simulate here on Earth is Mars's lower gravity Mars is only about 10 of the mass of Earth it's less dense though since its diameter is actually about 50 percent of Earth that puts its acceleration due to gravity at 3.7 meters per second squared compared to Earth's 9.8 meters per second squared meaning that Mars's gravity is just over 60 percent less than the strength of Earth's gravity we think a change in gravity could have a really big impact on a plant you know that's used to growing in Earth's gravity and not necessarily in the way that you might first think like I first thought okay well you know a shoot grows up and surely that's easier and lower gravity but actually it's that it makes it harder for the roots to grow down because without gravity how does a plant know which way down is so I'm no biologist but as I understand it this is controlled in Plants by a hormone called auxin and auxin sinks so for a shoot the more Orcs in there is the more growth it promotes whereas for roots the more auction there is the less growth there is so if you think about this in terms of like say a seed that has been planted sideways and as the root and the shoot starts to emerge image is when we can understand what auxin does so in the shoot the auction will sink under Gravity and promote growth in the bottom half but in the top where there's less Orcs in the growth will slow so in the shoot the auction will sink under Gravity promoting growth in the bottom half of the shoe but in the top path it'll sort of like put the brakes on the growth so the growth will be slower and so with this differential in growth speeds essentially what will happen is the shoot will start to grow directly upwards whereas in the root the opposite happens the auxin sinks inhibiting growth in the bottom half so slowing it down but promoting it in the top half where there's less aux in so it starts to go quicker in the top half which curves it round and the root starts to grow down this is known as gravitropism and now I've pointed it out you will see it everywhere so the idea was that in weaker gravity this auxing gradient might be affected but this is something we've already been able to test with the plant growing experiments on the International Space Station the ISS in microgravity pretty much zero gravity and in these experiments they still found this vertical distribution of auxin suggesting that auxin sinks of its own accord and it's nothing to do with gravity this is on the conclusions of the study by Phil and Paul in 2016 and essentially it's gravity independent so we should maybe be all right growing crops on Mars although there's been some other studies like this one by Kamal and collaborators in 2017 that suggested that plant cells themselves are damaged by low gravity so I guess we won't know how crops and plants are actually affected in the long term Anyway by the different conditions on Mars you know from the different soils the different nutrients available the different amounts of incidents Sun High and lower gravity we won't know how they're going to be affected until we actually try and have a go before we get to bloopers a huge thank you to brilliant for sponsoring this week's video brilliant is a stem learning platform with interactive courses on a huge range of science maths and computer science topics that get you to learn by doing the way I personally learn best brilliant lets you immerse yourself in a topic going at your own pace with extra help if you need it it's perfect for learning at home or on the go maybe like me you need to brush up on your biology a little bit seriously describing how auxing works for this video reminding me how long it has been since I thought about anything to do with Biology so I absolutely loved Brilliance computational biology course it allowed me to think about problems in biology from a computer science perspective which I was much more familiar with so I could start to think about DNA just like a computer code and then how that leads us to ideas in forensics and genetic ancestry seriously it was absolutely fascinating this course so if that sounds like something you'd be up for to sign up completely for free head to brilliant.org forward slash Dr Becky or you can click on that link in the video description down below and the first 200 people that do just that will get 20 off an annual premium subscription so thank you so much to brilliant for sponsoring this video and now we're all those players the real science from the fiction in my astrophysicist react series series Sean Connor is with me already people and we're one line in thank you oh it's dripped on myself a little bloody hell oh I just realized that if what if I slouch you like you can't see my cool t-shirt okay kill off any of the harmful pathogens so it can be used used so that it can be used this is controlled in a plant by the hormone called auxin I didn't look up how to pronounce before I started filming which I probably should have done because I mean I think it's going to be like you know like an aux cable in um because what else would it be you know it Orcs in but I'm constantly surprised so oh like toxin toxin oxen's very American I wouldn't say that oh oxen walks in yeah oxen auxin not I'll do um take a look at that star man Planet crops on my eyes oh man don't contaminate the surface otherwise we'll never know is there life on my Minds before now the day Joel

Channel: Dr. Becky

Views: 830,688

Keywords: dr becky, solar system, NASA, scientist, astronomy, space, cosmos, universe, cosmology, women in science, women in STEM, female physicist, physics, mars, perseverance, ingenuity, mars rover, science discussion, mars2020, water on mars, life on mars, curiosity, the martian, matt damon, andy weir, hail mary, astrophysicist reacts, potatoes, crops, martian soil, fertiliser, water, international space station, microgravity, zero-g, ISS, martian analog soil, heinz marz, biosignatures, plants, harvest

Id: jcciYoBVTmM

Length: 14min 50sec (890 seconds)

Published: Thu Aug 04 2022