Earthworms can reproduce in Mars soil simulant • Hacker News Board

Re: Earthworms can reproduce in Mars soil simulant

#31

Post by Tuna-Fish » Sun, Dec 24, 2017, 9:32 PM UTC

Dylan16807 wrote: post #25

Johnny555 wrote: post #21

Earlier quoted context omitted.

If these habitats are also housing people, then the atmosphere will likely be very close to Earth pressure and composition. The atmospheric pressure on the ISS is very close to 1 atmosphere, and it's an oxygen-nitrogen mix close to earth's atmosphere.

A mars mission won't be getting frequent short-hop trips from earth. I would expect the habitats to use reduced-pressure atmospheres with less to no nitrogen.

Then everything needs to be made of fire-retardant materials. Reducing the nitrogen content of the atmosphere has little deleterious effects for people, but makes fires easier to start, hotter, and harder to put out.

Re: Earthworms can reproduce in Mars soil simulant

#32

Post by YokoZar » Sun, Dec 24, 2017, 9:32 PM UTC

mratzloff wrote: post #20

meri_dian wrote: post #17

If we are able to conclusively determine that Mars is no longer host to life, should we try to seed the planet with carbon dioxide & methane producing organisms in order to create an atmosphere?

That wouldn't do much good unless we can re-establish the magnetosphere.

Mars has isolated pockets of "mini magnetospheres" that are suitable enough to block charged particles.

http://www.space.dtu.dk/english/Research/Universe_and_Solar_...

Re: Earthworms can reproduce in Mars soil simulant

#33

Post by [deleted] » Sun, Dec 24, 2017, 9:38 PM UTC

toomuchtodo wrote: post #27

throwawayaway12 wrote: post #26

Earlier quoted context omitted.

I think it is still an open (and hotly debated) question on if planets need magnetospheres to retain an atmosphere.

A magnetosphere is required to shield from charges particles and other harmful radiation.

[deleted]

Re: Earthworms can reproduce in Mars soil simulant

#34

Post by ethbro » Sun, Dec 24, 2017, 9:39 PM UTC

throwawayaway12 wrote: post #26

mratzloff wrote: post #20

Earlier quoted context omitted.

That wouldn't do much good unless we can re-establish the magnetosphere.

I think it is still an open (and hotly debated) question on if planets need magnetospheres to retain an atmosphere.

* also, retain an atmosphere "over long enough timescales"

From the MAVEN research papers I've read, we're talking ~5,000 metric tons / yr of atmosphere being stripped.

Which is a lot, but not an insurmountable lot.

Re: Earthworms can reproduce in Mars soil simulant

#35

Post by joshvm » Sun, Dec 24, 2017, 9:44 PM UTC

Dylan16807 wrote: post #25

Johnny555 wrote: post #21

Earlier quoted context omitted.

If these habitats are also housing people, then the atmosphere will likely be very close to Earth pressure and composition. The atmospheric pressure on the ISS is very close to 1 atmosphere, and it's an oxygen-nitrogen mix close to earth's atmosphere.

A mars mission won't be getting frequent short-hop trips from earth. I would expect the habitats to use reduced-pressure atmospheres with less to no nitrogen.

What would you expect the habitats to have instead of nitrogen? You wouldn't want a high oxygen atmosphere. Not only is it an extreme fire risk (see Apollo 1), but humans aren't built for it - oxygen toxicity exists.

Re: Earthworms can reproduce in Mars soil simulant

#36

Post by JumpCrisscross » Sun, Dec 24, 2017, 9:49 PM UTC

dweekly wrote: post #9

Of course it would turn out that the first thing we could grow and eat on Mars would be rocket.

For the confused, rocket is called arugula in American English [1].

[1] https://en.m.wikipedia.org/wiki/Eruca_sativa

Re: Earthworms can reproduce in Mars soil simulant

#37

Post by maxk42 » Sun, Dec 24, 2017, 10:07 PM UTC

YokoZar wrote: post #32

mratzloff wrote: post #20

Earlier quoted context omitted.

That wouldn't do much good unless we can re-establish the magnetosphere.

Mars has isolated pockets of "mini magnetospheres" that are suitable enough to block charged particles. http://www.space.dtu.dk/english/Research/Universe_and_Solar_...

I think he was assuming the subject was terraforming.

Without a magnetosphere, the atmosphere will keep being blasted off into space continuously, and it'll be impossible to terraform.

Re: Earthworms can reproduce in Mars soil simulant

#38

Post by c3534l » Sun, Dec 24, 2017, 10:15 PM UTC

robinduckett wrote: post #3

But can they reproduce in the soil at the same range of air pressure found in habitats, with the same gravity / gas mixture? Can they still reproduce after 50 years?

If not, maybe we can engineer a breed of worms that can.

Re: Earthworms can reproduce in Mars soil simulant

#39

Post by gozur88 » Sun, Dec 24, 2017, 10:16 PM UTC

Dylan16807 wrote: post #25

Johnny555 wrote: post #21

Earlier quoted context omitted.

If these habitats are also housing people, then the atmosphere will likely be very close to Earth pressure and composition. The atmospheric pressure on the ISS is very close to 1 atmosphere, and it's an oxygen-nitrogen mix close to earth's atmosphere.

A mars mission won't be getting frequent short-hop trips from earth. I would expect the habitats to use reduced-pressure atmospheres with less to no nitrogen.

The atmosphere of Mars contains nitrogen. It could be extracted and concentrated to provide the same percentage as earth's.

Re: Earthworms can reproduce in Mars soil simulant

#40

Post by gozur88 » Sun, Dec 24, 2017, 10:18 PM UTC

marrone12 wrote: post #12

aetherson wrote: post #8

Earlier quoted context omitted.

They don't really need to be radiation shielding or light emitting. People don't need to live there, just plants and animals. And insolation on Mars is sufficient for light.

Excessive radiation can also kill plants and animals

Plants are pretty tolerant of solar radiation. Far more so than humans.

In any event, what you'd probably do is use reflected light to filter out high energy particles.