Thanks to Squarespace for sponsoring today’s
video. Many of us have seen the Martian, in my opinion,
a great film about surviving on the Martian surface. One part of the film focused on growing potatoes
using Martian soil, but, how practical is that in reality? Does Martian soil really have the nutrients
needed for plants to grow? And would there be any adverse side effects
from eating produce grown on Mars? As it turns out, Martian soil does in fact
have a lot of the essential nutrients needed for plants to grow, depending on where exactly
you are on Mars. Just like Earth, with some areas that have
nutrient poor soil and some with nutrient rich soil, some parts of Mars would be better
suited for growing plants than others. However, the soil on Mars is more like regolith,
it hasn’t had a history of worms, insect and plants mixed in. In 2016, researchers grew tomato, rye, radish,
pea, leek, spinach, garden rocket, cress, quinoa, and chives in an imitation Martian
soil on Earth, producing only slightly less produce than they would have in Earth soil. Interestingly, they did the same experiment
again with imitation Moon soil, which produced about half the amount of produce, yet these
crops still grew, with only spinach really struggling to perform! However, it should be noted that organic matter
was added to the soil, in this experiment cut up grass, to fertilise the soil, and fluff
it up, allowing water to pass through the soil to the roots. Without that, the plants wouldn’t have lasted
long. Another barrier scientists would have to get
over though is the abundance of heavy metals and most importantly, something called calcium
perchlorate in the Martian soil. Calcium perchlorate is a salt, which – like
heavy metals - is toxic if consumed in large quantities. This perchlorate and metals in the soil would
be absorbed into the plants, not so great for the plants anyway, but humans would then
also absorb it into their system when they eat the plants. But perchlorate isn’t all bad, in fact it
could help humans survive on Mars. For one thing, it sucks water out of the air,
which can then be used as liquid water. It also can give off oxygen, again, another
critical checkbox for survival ticked. So, in short, it seems there are two major
problems to be overcome when growing plants on Mars. First is the need for fertiliser. Going back to the film and book “The Martian”,
Watney overcame this problem by using feces from the toilet as fertiliser. Typically, this is dangerous as feces contain
pathogens, however if the feces have been processed to kill the pathogens, it can then
safely be used as fertiliser. Once production gets underway, you could always
use the compost collected from old plants and food. The second problem is the toxic perchlorates. Well, this has a simpler solution than you
may think. Running water through the soil would rinse
the perchlorates out, and you could then separate the water and perchlorates later so nothing
is wasted. The alternative is to use perchlorate eating
bacteria, which give off oxygen as a by-product. There is a reason why growing plants in future
colonisation efforts is so important, not only does it make the colony self-sufficient
but there is also evidence that fresh foods, such as tomatoes, blueberries and red lettuce
are a good source of antioxidants. Having fresh food like these available in
space could have a positive impact on people's moods and could also provide some protection
against radiation in space. But without actually doing it, it’s hard
to say how well it will work on Mars itself. Although, it should be said that plants have
been proven to be versatile. They have grown in Mars simulations on Earth,
they’ve even grown on the International Space Station. The key will be whether plants grown on Mars
are safe to eat, or not. And the only definitive way to find out is
to grow some plants on Mars. Thanks again to Squarespace for sponsoring
this video. Squarespace gives people a powerful and beautiful
online platform from which to create your own website. They have bunch of features which you can
integrate seamlessly into your own website, like their audioblock feature to embed your
podcasts or music, with ITunes support. Or something I find particularly useful, which
is the ability to link various social media platforms to your website and embed videos! So, if you’re looking to build a website,
give it a go! If you use the link squarespace.com/astrum
you can try it out for free and get 10% off your first purchase. Thanks for watching! These Astrum Answers questions are picked
in a fortnightly poll by my Patreons and members. If you’d like to participate and also support
the channel, find the links in the description! And if you have a question you’d like to
see answered, ask in the comments below! All the best, and see you next time.
