Study: Potatoes can grow on Mars | Hacker News Reader

Study: Potatoes can grow on Mars

upi.com

230 pointsMz139 comments

From the article:

"The box mimics the day-night patterns of Mars, as well as its temperature, air pressure and atmospheric composition."

Wait, really? They're growing plants in what's practically a vacuum and at subzero temperatures? Really? That seems... stupendously unlikely... to me. Not that I wouldn't love to be wrong, mind.

Anyone have a link to actual data? Everything linked to is just press fluff.

Update: Actual articles on growing plants at very low pressure:

https://science.nasa.gov/science-news/science-at-nasa/2004/2... --- at 1/10 of an atmosphere, plants' metabolic balance gets screwed up and they go into drought response and die, no matter how much water is actually available.

http://online.liebertpub.com/doi/abs/10.1089/ast.2009.0362 --- but lichen's probably fine.

It sounds from the original press release [1] like they significantly enrich the soil to make up for that.

[1] http://cipotato.org/press-room/blog/indicators-show-potatoes...

On the Cody's Lab YouTube channel, Cody did expose potato plants to Martian atmospheric pressure for short periods of time. Apparently, potato plants can survive a decompression event, so long as you get them back to an Earthlike environment promptly.

https://www.youtube.com/watch?v=z8VPvBr4ppU

I doubt they could survive extended exposure, though.

And 'survive' is something far different than 'grow'.

Even saying they are growing doest mEan they will work, I've peeled many potatoes and they grow eyes if left long enough...in the dark too!

So does this mean the environment was only partially simulated? It sounds like we're assuming Martian potatoes will be grown in pressurized environments.

Given an inexpensive transparent material with very high tensile strength and resistance to weathering in the Martian environment, I could see a passive pressurization/thermal regulation scheme for greenhouses on the surface of Mars that relies only on, say, a heat source, some valves, and some consumable gasses. I could imagine such schemes using mainly water as an input.

That said, such a material would be asking for a lot. Then, there's also the UV and other radiation to consider.

Just replace/recycle it regularly.

I reckon there is value in only partially simulating the environment and grow lots of potatoes at scale. Take those potatoes that succeed and breed them and repeat. With every iteration, change the environmental conditions to better simulate Mars. Over successive generations, I reckon we can get to potatoes (and other plants) that fair well.

The big question is how you optimize this process to assist evolution in moving faster.

It will need many generations before you have a plant that can live in a natural martian environment. I don't think you'll be able to get much nutrition out of it anymore.

The less demanding the crops are, in terms of sheltering them from Mars, the cheaper they will be to grow. So it's useful, even if you don't get them to a natural Martian environment. Lowering the temperature and pressure they can grow at would still be a win.

Only if you don't lose too much yield. Look at high mountain plants on Earth, they're hardly edible and live in a much friendlier environment than Mars.

Near impossible, on Earth there are no plants in most of Antarctica. And that has more water than Mars. There is no solution that matches all the constraints.

There arent many minerals available on ice and stuff gets buried under snow quickly too.

I ran a similar experiment at home, albeit with a fern rather than potatoes and without simulating martian light.

My fern started to perish (and it was a well established plant). The biggest problem I'm facing at the moment is that Mars is extremely nitrogen deficient.

https://reprage.com/post/marsarium-9

https://www.reddit.com/r/Colonizemars/comments/5vi52v/inspir...

That reminds me of an Asimov story, "Founding Father", involving ecosystem change on a planet by stranded astronauts.

Best places to find a copy these days?

Any central public library is fully stocked on Asimov.

It seems that this short story was originally published in an old science fiction magazine (that my local library doesn't stock). Was wondering if it also made its way into a compilation of some sort. Google hasn't turned up anything for me yet.

Contained in "Buy Jupiter and Other Stories" Available on amazon (https://www.amazon.com/Jupiter-Other-Stories-Isaac-Asimov/dp...)

Is this the story? http://www.young-adult-books.com/read/buy-jupiter-and-other-... (link says "buy", but looks like the entire story is on that page)

Thanks for the link! Apparently 'Buy Jupiter' it self is a story (so all the stories on the page are free)

Can you imagine if someone told Asimov that his story "Buy Jupiter" would be mistaken for a "link" to buy a copy of his work, by someone reading on an international network of computers that have access to all of the information in the world - and were so overrun with advertising that his own title was mistaken for one. Given "Buy Jupiter's" plot summary - https://en.wikipedia.org/wiki/Buy_Jupiter [1] - this is extremely apropos!! Some things never change :)

[1] WHICH I'M LINKING ON A FREAKING ENCYCLOPEDIA GALACTICA THAT CONTAINS IN EVERY LANGUAGE ALL OF THE GENERAL KNOWLEDGE OF THE WORLD (WIKIPEDIA).

https://archive.org/details/Galaxy_v24n01_1965-10 page 165 of Galaxy magazine

That's awesome. I want to do that.

It'd be interesting to measure the gas composition inside the chamber --- although I suspect the bodging together a gas spectrometer is going to be a bit problematic.

This all at at one atmosphere, though, isn't it? I see you have a vacuum pump, but that enclosure doesn't look like it'd be safe to evacuate. I'd like to try low pressures. Intuitively I'd expect hard-skinned plants like cactuses to cope better --- but intuition is frequently wrong. Another interesting thing to try would be to use one atmosphere of absolute pressure but have accurate partial pressures of carbon dioxide and nitrogen to simulate the Martian atmosphere...

Yeah one atmosphere, but with the same atmospheric mix as what is on Mars. I was trying to simulate compressing the Martian atmosphere into a pressurised and thermally insulated greenhouse.

My enclosure is only good down to about 0.8 atmospheres, below that the big rubber seal around the door starts to leak. The vacuum pump is used when mixing the atmospheric composition.

Figure the first martian plants would live in a pressurised, insulated greenhouse. There are some neat passively heated designs around.

I think my next experiments will be with legumes trying to fix nitrogen and improve the soil. The way I see it, pressure, warmth and light are all problems for which we have existing solutions. The real question is can we get stuff to grow without importing tons of fertiliser?

Using a well established plant might be worse than using a young one. They grow into the situation they find and adapt. If your plant is used to standard house plant conditions it might be harder compared to one used to bad soil and little water. But probably you already took that into consideration?

would it not be better to start with something like a cactus?

I wonder if we could do artificial selection, breeding a couple generations in progressively lower atmosphere, and only keeping those that don't go haywire

Perhaps they bred the plants to have better low-pressure resistance?

I think this article is wrong about the temperature. There is little information available but here is the original press release http://cipotato.org/press-room/blog/indicators-show-potatoes...

From what I can gather they used soil from some Peruvian desert and increased the CO2 in the chamber. But there is no mention of simulating the -80F night temperatures typical on Mars.

I'm pretty sure Martians measure temperature in Celsius.

You say that now. Wait til they colonize!

0 degrees Celsius being the freezing temperature of water at sea-level atmospheric pressure, that doesn't make much more sense either :-)

Why not? That's just one of the ways to measure the "constant" 0 degrees Celsius. What that temperature is doesn't change just because you're at different air pressure. You don't say "water boils at 100 degrees celsius at every altitude," you say "huh neat water boils at different temperatures at different altitudes."

technically it's defined as 0.01°C being the triple point of water. And since the solid-liquid boundary in the phase diagram[0] is relatively stable across wide pressure ranges that means that 0°C being the melting point is not just true at a single pressure value.

[0] https://upload.wikimedia.org/wikipedia/commons/0/08/Phase_di...

Celsius is equally arbitrary to Fahrenheit.

No, Martians measure in Nano Yocto Planck Degrees above Absolute Zero, I hereby dub that unit the Plancktigrade.

Celsius at least has a family of units that mesh with it precisely. To heat one cubic centimetre of water up 1°C takes 1 Joule. It also essentially weighs 1 gram at normal temperatures.

How many BTUs does it take to heat up one cubic foot of water by one degree Fahrenheit?

It takes one BTU to heat one pound of water, one pint, one degree Fahrenheit.

The units may be arbitrary, but they still line up.

Yeah, but a pound of water is not a cubic foot. A pint has nothing to do with inches.

That has nothing to do with temperature.

You can keep metric and use Fahrenheit with very little change.

And you got your units wrong anyway: "To heat one cubic centimetre of water up 1°C takes 1 Joule" - you mean 1 calorie, not 1 Joule.

Change Celsius to Fahrenheit and only calorie changes, and since it's anyway not part of SI it makes little difference.

Joule is the main energy unit, and it's not tied to Celsius at all.

I totally get the arguments for metric - except for temperature. For temperature Fahrenheit is the better scale.

Look here: https://en.wikipedia.org/wiki/International_System_of_Units#...

And notice how Kelvin stands alone - it's not tied to any other unit. It can be replaced with almost no impact.

A difference in temperature has the same numerical value in both degrees C and K. Often differences in temperature are all we're interested in so C is often interchangeable with K.

If you use Fahrenheit, then you lose that easy relationship unless you also use Rankine for absolute temperature. But nobody, not even Americans, has even heard of Rankine so it would be a far bigger challenge to get anyone to use that than just Fahrenheit alone.

Perhaps an even more elegant unit for temperature would be thermal energy per degree of freedom per particle, which would be joules in SI. I'm not sure if that's really correct tho.

> A difference in temperature has the same numerical value in both degrees C and K.

I know, I used them basically interchangeably in my post.

> unless you also use Rankine

If people used Fahrenheit more often they would use Rankine more often as well (and yes, I was aware of it before this discussion).

> which would be joules in SI

Joules is a unit of energy, not temperature. You need to multiply by entropy to get temperature.

It would be one thing if the unit for temperature was based on the SI units, fine. But it's not - it's completely arbitrary, and since that is the case you might as well use the more usable Fahrenheit.

If I were doing it I would redefine it such that 1 joule of energy applied to 1 gram of water = 1 new-degree. (Right now it's 4.2 joules.) That would make the temperature scale less coarse, which is good. Then make absolute zero -1000 new-degrees.

Isn't temperature an energy scaled by the Boltzmann constant? That means it's proportional to the energy of something. Why not just use that energy directly instead of converting it to another unit? That's what I means about using Joules for temperature - divide kelvins by Boltzmann's constant

Why on earth would you make absolute zero anything other than 0? That's the major problem of Fahrenheit and the reason Celsius is not the SI unit. Instead, you could put a human-level temperature at a round number like 1000 new degrees so everyone always has the leading 1 in there for everyday values.

> Isn't temperature an energy scaled by the Boltzmann constant?

Only for an ideal gas. For all other materials the scale number is different. That's why temperature is a unit of its own, and it not just energy.

> Why on earth would you make absolute zero anything other than 0?

I want a "human" oriented scale, that is also tied into SI.

Ah, you're right about calorie vs. Joule. That is a bit rough around the edges.

> For temperature Fahrenheit is the better scale.

Yeah, no. It's a stupid system. It's not even calibrated properly. 100° was supposed to be body temperature. They got it wrong. 0° was the lowest temperature they could measure at the time because that's when mercury froze. That's so useful! I really want to know if the mercury I carry around all the time is going to freeze outside.

Meanwhile °C is simple: 0°C is "watch for ice" and 100°C is "water boils" (minus altitude factor).

I don't know how you can praise Kelvin and slam Celsius since they're the same "size", it's just that the zero point of Kelvin was set to absolute zero instead of the freezing point of water. °C = °K + 273.15. That's it.

> That is a bit rough around the edges.

Correct. It would be one thing if Celsius is somehow tied into the rest of the SI units, but it is not, which means we can replace it.

> It's not even calibrated properly.

Who cares if they got the calibration of Fahrenheit wrong, at the end of the day it's more usable than Celsius for humans.

0 Fahrenheit is the temperature when it's really cold outside, 100 is when it's hot. It doesn't get simpler than that. If you are outside those ranges you need to take special precautions. No, I don't care about mercury either, but I do care to know when it's cold.

It's not that hard to remember 32 for ice. With Celsius you need to deal with negative temperatures all the time, and worse, the size of the degrees is too coarse.

> 100°C is "water boils"

And exactly how often do you need to measure the temperature when water boils? Probably about as often as I freeze mercury. So 100 is a very useless range on Celsius - you are using your "best" numerical range on useless temperatures.

On the other hand it's quite common to want to know when it's hot enough that you will sweat. Above 100 (body temperature) you will sweat.

Labs and Ovens don't really care about which exact unit, so let them deal with the higher (or lower) numbers - the only time it matters is for ordinary humans checking the weather.

> I don't know how you can praise Kelvin and slam Celsius

You misread, I did not praise Kelvin, I said we could replace it.

> It's not that hard to remember 32 for ice. With Celsius you need to deal with negative temperatures all the time, and worse, the size of the degrees is too coarse.

Well, the whole world manages to deal with °C and only America and a handful of backwater countries insist on using °F.

"Too coarse" is absurd. People just measure to the nearest 0.5°C if you want to get all fussy, but that's not normally the case. It's 12° out? Wear a jacket. 12.0 vs. 12.5° isn't going to change that.

It keeps the numbers smaller. Temperatures here flop between -40°C and +40°C, so the numbers never get large. Meanwhile in the US you see temperatures of 100°F all the time as well as negative ones like -30°F. It's a much wider spread for no real reason.

I hope you know the only reason America didn't get with the program and metricize like it was fully intending to do in the early 1980s is because Reagan was an asshole.

I'm onboard for metric - just not for temperature.

Just because you manage to deal with C doesn't make it better.

Do you see the parallels? You tell Americans all the benefits of metric, they don't care. You tell Europeans all the benefits of Fahrenheit, they don't care.

People don't want to change.

> It keeps the numbers smaller.

No, it doesn't. You need 3 digits since you need the decimal (-20.5).

I can't think of a weather station that uses decimals, the forecasts and current temperature reports are almost always whole numbers. My Nest thermostat goes to the closest 0.5°C because I guess why not, but even that seems overkill. Most systems go to the nearest whole degree.

Decimals are only for those who are making a fuss over nothing unless they're doing something that requires precision, like chemistry or in rare cases cooking.

There's no benefits to Fahrenheit. If you want to argue they're both arbitrary, fine, but the entire world uses °C, so get with the program.

Good luck getting the US to ever change. I'm personally on the side that Fahrenheit is more useful for day-to-day usage, because it has a range calibrated to the temperatures experienced in the part of the world I happen to live in. But it would take a whole generation to get people to change their frame of reference into Celsius, which isn't likely to happen, because the biggest interaction people have with temperature is the daily weather report, and it's primarily older people that watch the news.

I could get on board with kilometers, if I had to, because the conversion factor is simple enough to do in your head (roughly 3/5), but trying to figure out what anything is in Celsius is just a little too complicated.

So, 40 or 50 Degree for when it's dangerously hot is too hard to remember, just like 32 for freezing is somewhat easier than 37 for body temperature?

Why let's just change the numeral base to 5, or use roman numerals for that matter. Then scientists can finally stop to convert some arcane unit to get to the Standard International Base Unit, ie. Kelvin. At least everyone gets to convert their numbers then and it's only a division by two, too.

</rant>

It's more that you can't tell the difference between 30C and 30.5C. No one ever forecasts temperatures using decimal degrees here in Australia.

You only need decimals for highly accurate measurements, but at that point you'd need decimals for Farenheit as well.

> You tell Europeans

Erm, how about the rest of the world?

Judging by the title of this thread, I think the GP meant to type Europans, not Europeans.

To me "hot" starts at 80F and "cold" around 40F. When cooking I frequently care about temperature relative to the boiling point when deciding what temp to set the oven or water bath to.

"""And exactly how often do you need to measure the temperature when water boils?"""

I drink green tea a lot. You pour the water at 70-75 degrees C. It's a lot easier to do the math of how much water you need to add to instantly cool the water from the water boiler down to that range.

"""Labs and Ovens don't really care about which exact unit, so let them deal with the higher (or lower) numbers - the only time it matters is for ordinary humans checking the weather."""

What? I use temperature more when cooking/BBQing than when checking the weather.

"""With Celsius you need to deal with negative temperatures all the time"""

This is a feature, not a bug. Negative number -> below freezing.

"""0 Fahrenheit is the temperature when it's really cold outside, 100 is when it's hot. It doesn't get simpler than that. If you are outside those ranges you need to take special precautions."""

I also need to take special precautions within these ranges. Most notably switching between summer/winter tires.

Yeah, but inches are a unit of length and pint is a unit of volume. Therefore a pint is more relevant here. Yeah technically a cubic inch/foot is volume, but it's not the purpose-built one.

To be honest, the volume system in US customary is the only one that makes sense. Everything's power-of-two friendly. If we could revise the others to mesh with that idea then we could have one power-of-10 system (metric) and then a power-of-two system.

That's why there's acre-feet! Because gallons aren't good enough.

Is that a US or a UK pint?

If we are talking about Mars, then the colony might not like the Earth-centric origin[1] of the definition of meter, but be ok with human centric foot.

1). The original definition of meter was based on the size of the Earth.

I thought Kelvin would be the appropriate unit for temperature differences, deg. Celsius be only used for absolute values.

I'm pretty sure it's supposed to be pirate and/or ninja related[1], so you're missing a great opportunity to name it pirate-plancks.

1: http://www.urbandictionary.com/define.php?term=pirate%20ninj...

arbitrary yes, equally, no.

Kelvin, FTW

They use Kelvin.

Source: KSR's Red/Green/Blue Mars trilogy ;-)

Potatoes, especially sweet potatoes have been cultivated at high altitude for centuries in South America. You are probably right about -60C being too low, but if they provide some shelter potatoes could handle very low overnight temperatures without needing the amount of climate control that other crops would need. Which is one reason why they are looking at this crop.

You may be able to grow potatoes on Mars, but growing them in the Andes doesn't really get you that much closer to Martian conditions.

Average pressure on Mars is about 0.6 kpa which is a trifle less than the pressure at Cusco which is approx 65 kpa pascals. Mt Everest is still about 37 kpa.

I believe you'd have to go about 50km above sea level to hit the average pressure of Mars.

Sweet potatoes aren't even closely related to standard potatoes though. They are related to a morning glory where as standard potatoes are related to the tomato.

I think it's relevant to life on Mars that plants don't grow at antartic temperatures, which are:

> The highest temperature ever recorded at the Amundsen–Scott South Pole Station was −12.3 °C (9.9 °F) on Christmas Day, 2011, and the lowest was −82.8 °C (−117.0 °F)

Mars:

> A summer day on Mars may get up to 70 degrees F (20 degrees C) near the equator, but at night the temperature can plummet to about -100 degrees F (-73 C).

I know, I saw Matt Daemon grow potatoes on Mars in an in-flight documentary called "The Martian".

/sbin/mattd

Can I get in on the joke? :)

They're making a joke about the misspelling of Matt Damon. "Daemon" is a computing term [0] and /sbin/ is a folder that you might want to put a Matt Daemon in. (Also, daemons are often named with a "d" at the end, like "etcd" or "mattd".)

[0] https://en.wikipedia.org/wiki/Daemon_(computing)

The actor is Matt Damon. Parent spelled it Matt Daemon, as in a hypothetical *nix process at /sbin/mattd

If this were Reddit we could keep this going until we had a meme about Matt Damon running in the background of movies, and a whole corpus of images where he's been photoshopped to be doing just that.

Now I'm kind of regretting this conversation isn't on Reddit.

You can fix that, you know.

Yeah, but I'm not one to force conversations. Maybe I can gently steer it the next time a Matt Damon relevant post comes up in gifs, assuming I get there before it's swamped in comments.

In the meantime, I guess I could make some gifs. Because that's a much better use of my time than research, learning, or taxes...

https://github.com/ralphbean/mattd.core

I definitely read an article after that movie came out about confused moviegoers that thought it was based on a true story.

On one end of the spectrum, you have people who doubt that we landed a man on the Moon. On the other end, you have people who think we had a man grow potatoes on Mars.

What a time to be alive.

I bet you anything that there is some (however tiny) overlap between the two populations.

Relevant Mitchell and Webb Look: https://www.youtube.com/watch?v=P6MOnehCOUw

Why exactly did this experiment require a satellite? For biological purposes Martian gravity is probably closer to Earth gravity than to microgravity, and all the other conditions could be reproduced for cheaper and at larger scale in a ground laboratory.

This smells of a publicity stunt to me.

Martian gravity is lower than earth gravity, and if the test was run in earth like gravity there could be concerns that that variable would have an effect. By conducting the experiment in lower gravity than Mars's, it's hard to doubt that martian gravity would pose a problem.

Practically speaking, honest question, how do we simulate lower gravity for extended periods other than orbit? Seems hard.

Technically, what you're doing in orbit is free fall ;).

I've seen devices used to simulate microgravity in cell research. Devices like these:

http://www.grimm-space-research.com/RPM/RPM.html

As far as I understand, the basic idea is to spin the sample in such a way that over time that the forces acting on it (including gravity) average out to 0. Apparently the processes they're interested in occur slowly enough that they behave as if in free fall.

> This smells of a publicity stunt to me.

I don't know, some people are irrational about plants and farming. Sure we've grown all kinds of plants in orbit before, but maybe potatoes need to commune with the Earth in order to grow. Turns out that potatoes obey the laws of physics and chemistry as well.

From the photo, I'm pretty sure the CubeSat is on the ground. http://nkxms1019hx1xmtstxk3k9sko.wpengine.netdna-cdn.com/wp-...

The photo is from their press release: http://cipotato.org/press-room/blog/indicators-show-potatoes...

Isn't a cubesat on the ground called... a box?

There's no mention of a past or future launch in the article, so this looks like an egregious case of buzzwording.

They didn't mention whether they tried to simulate the radiation levels plants would experience on Mars in their experiment. I don't know whether that would change the results.

https://www.newscientist.com/article/dn22520-mars-is-safe-fr...

I didn't know the answer so I googled it. Apparently it isn't that high.

"Readings from NASA’s Curiosity rover suggest radiation levels on the Red Planet are about the same as those in low Earth orbit, where astronauts hang out for months on the International Space Station."

> radiation levels on the Red Planet are about the same as those in low Earth orbit

... which coincidentally is where the experimental potatoes in the article were grown.

Unfortunately not, looks like they never got round to launching the cubesat.

Add magnetic field at Lagrange point.

"Scientists with the International Potato Center" made my day.

They're a Russian import.

Shouldn't that now be the Interplanetary Potato Center?

That, and their President is one W. Ed Russet Burbank, and he can (allegedly?) grow potatoes where noone else can. #respect

Soon "potato scientist" will be as impressive as - if not more than - "rocket scientist".

Second post on this thread, and sadly it's as much a joke as the first.

From this point on, I'm going to cease saying "it's not rocket science," and start saying "...it's not potato science."

Important to understand this doesn't mean potatoes can grow in perchlorate soil.

Here's a relevant related link:

https://www.reddit.com/r/Mars/comments/4ib9d9/never_freezing...

The post introduces a model of a passive (pressurized) greenhouse on Mars that manages moderate temperatures just using insulation and some soil and water for thermal inertia.

But can they grow in Martian soil? Its regolith is missing crucial nutrients, methinks. Otherwise, wow! The Martian's premise might actually be realistic!

It's possible to grow potatoes hydroponically, so growing them in unprocessed Martian regolith is unlikely to be important until the number of Martians hits six figures.

So you're going to bring your own soil everywhere? That's the unsustainable part. Terraforming would take thousands of years.

Hydroponic farming doesn't use soil ...

https://en.wikipedia.org/wiki/Hydroponics

Bring some worms, use human-derived fertilizer. Not terribly impossible.

And how does that scale for the next generations of worms? What will the worms eat?

Hydroponically means "using water as a medium", so not bringing your own soil and depending on whether there's water available on Mars. You would still need to put nutrients in the water, but it would be a path to take until you get composting working.

> depending on whether there's water available on Mars

Actually, we've recently confirmed that there are at least five million cubic kilometers of water ice on Mars ...

https://en.wikipedia.org/wiki/Water_on_Mars

https://en.wikipedia.org/wiki/Water_on_Mars#Present_water_ic...

If anything can be grown on Martian soil--whether substantially nutritive or not--that can self-sustain and propagate on its own, I wonder if that is an avenue for terraformation.

> It was a pleasant surprise to see that potatoes we've bred to tolerate abiotic stress were able to produce tubers in this soil,

Did they really produce tubers? That'd be impressive, but the video only shows "initial plant growth".

On video there were liquid water. I didn't know such exist in mars.

Potatoes don't exist on Mars, either. But if we're going there, and bringing potatoes, we'll either be bringing water, or distilling it there.

> we'll either be bringing water, or distilling it there

Probably just melting some of the more than five million cubic kilometers of water ice that has been identified at or near the surface of modern Mars ...

https://en.wikipedia.org/wiki/Water_on_Mars

If you google "water on Mars," you come up with recent research saying, yeah, there is water there, such as: https://www.nasa.gov/press-release/nasa-confirms-evidence-th...

No mention of perchlorate.

"CubeSat indicator experiments prove potatoes can grow on Mars. "

That's a pretty flagrant abuse of the word "prove". "Suggests" would be a better choice.

But how do they simulate Martian gravity?

They grew them under microgravity conditions in orbit, so they probably aren't going to have trouble coping with 2/5ths gravity.

The box full of potatoes is falling from a great height with a fairly large parachute? That wouldn't really give the potatoes a very long time to demonstrate growth, though.

just enough time for them to think "oh no, not again" really

I imagine one of the biggest challenges is removal of perchlorate salts from the regolith.

Hey guys, I helped build the Cubesat, any questions - Fire away!

What was the atmospheric pressure during the tests? Martian like?

It is about 40% of Earth's pressure. So low, but not as low as the actual pressure on Mars, which is too low to even consider. This assumes a greenhouse environment but without the necessity to create exact earth pressure, making it easier to maintain, using less energy.

Hi guys, I helped build the Cubesat. Any questions: Fire away!

Hey! Great that you answer questions. A question I had was if you took the temperature into account in your experiments.

A second question I has was: how similar is the sand you are using to real martian sand?

Do you have any images of the resulting potatoes? Would they be edible?

So, we are regulating temperature in the cubesat. We're assuming the best conditions possible on Mars, which is summer near the equator. This means up to 20°C during the day and around zero at night (if you watch the timelapse you can occasionally see the humidity freeze and defrost, dripping on the soil)

The sand is very similar to Martian soil samples observed by various NASA landers over the years. It comes from a very special region in the Atacama desert called Pampas De La Joya. Our lead biologist, Julio, has been doing experiments there for years. You can read more about it on potatoes.space/mars

Lastly, the potatoes are still growing, but we expect them to be edible. Tests done outside the cubesat prior to this, growing potatoes in the soil from La Joya, were safe to eat.

"If we can't get them out, we'll feed them out." - King Edward I, Braveheart

well duh, matt damon did it :P

is that you Mark Watney?

Hey, I read that book too.

Potatoes on Mars? Poland can into space!

And Latvia! Except once on Mars we find potato is rock halucinated as potato due to starve.

That headline is not true.

Because we don't actually have potatoes growing on Mars, there is a lot of information we could potentially be missing, like microbes we haven't discovered, effects of the radiation and little atmosphere, or (going for an extreme example here) a rabbit-like creature that we have never been able to detect yet, that eats the potatoes while we're not watching.

What we've accomplished with this experiment is only to "Grow potatoes in the closest approximation to Mars setting that some scientists thought of".

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