Make Pluto a planet… again?

Listen to two Science enthusiasts (I guess you can call them geeks) talk about an Astronomy feud that I thought was long buried: Is pluto a planet?

I know… #firstworldproblem…

Continue reading “Make Pluto a planet… again?”

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Farming, the Last Frontier

Have you seen the movie “The Martian”?
If you are looking for a feel good, Cast-Away-meets-MacGyver-kind-of-movie for this rainy Saturday afternoon, this is your fix.

With the help of Science, no problem’s too big for botanist-astronaut Mark Watney!

And if you are a fan of potatoes, then you’ll have a full plate (pun intended).
Mark Watney goes back to basics, relying on food rationing and some farming, in order to survive a solitary and famished sojourn in Mars. His major challenge rising a spacestead was the lack of water, but NASA scientists list other limitations for space farming as microgravity, harmful radiation and reduced light and pressure.

NASA plans to grow food on future spacecraft and on other planets as a food supplement for astronauts (top right). Astronaut Kjell Lindgren corrals the supply of fresh fruit in the international Space Station - ISS (top, left). Astronauts on the ISS harvest and savour
NASA plans to grow food on future spacecraft and on other planets as a food supplement for astronauts (top left). Astronaut Kjell Lindgren corrals the supply of fresh fruit in the international Space Station – ISS (top, right). Astronauts on the ISS harvest and savour “Outredgeous” red romaine lettuce from the Veggie plant growth system (bottom).

NASA has invested millions of dollars in space farming research and when you think it costs $10,000 to ship just 1 pound of food to the International Space Station you understand why.This August, six astronauts at the International Space Center became the first to eat lettuce grown more than 250 km above the earth’s surface!!! Other crops were cultivated before but sent back to Earth for research.

I would like to focus your attention on the challenges of farming in a place where gravity is greatly reduced or even inexistent.

If I remember correctly from my plant physiology classes*, plants have a refined sense of knowing what is up and what is down. But what happens up there in space?
Plants respond to gravity (gravitropism) by growing their roots down into the soil and their stems up to reach the sunlight. But what’s their stimulus? How is gravity perceived?


Scientists developed the Starch-Statolith hypothesis: at the tips of roots there are special organelles (statoliths) that bear tiny granules of starch, which, pulled by gravity, settle in the bottom of the cells triggering the release of the hormone auxin. Auxin promotes root epithelial cell elongation and consequent bending because of the weight.

Enlarged (Bar = 300 µm), longitudinal view of an Arabidopsis primary root. Gravity sensing in roots occurs in the cells of the root cap (inset), which contain dense, starch-filled amyloplasts (purple dots). Retrieved from Am. J. Bot. January 2013 vol. 100 no. 1 143-152
Enlarged (Bar = 300 µm), longitudinal view of an Arabidopsis primary root. Gravity sensing in roots occurs in the cells of the root cap (inset), which contain dense, starch-filled amyloplasts (purple dots). Retrieved from Am. J. Bot. January 2013 vol. 100 no. 1 143-152

Oddly, the area where gravity is sensed is often far away from the area where growth happens and the mechanism for the transmission of this message is still poorly understood.
Grasping the mysteries of plant growth will help select the crops which use resources more efficiently for long-term space missions and colonization.
Providing fresh and nutritious food for cosmonauts is the immediate benefit of space farming, but growing veggies in outer space may also provide oxygen for the crew, help recycle water and also provide a recreation activity.


For all of you, who are skeptic about space exploration and do not see the point for this research, I must add that understanding how plants anchor in the soil and acquire nutrients and water also benefit agricultural practices and bioenergy management here on Earth. This research will impact our understanding of how plants recover from landslides, survive severe droughts or subsist on depleted soils.
“The Martian” helped me abandon the idea that space exploration is essentially pointless and a luxury when we think of what is yet to explore here on Earth and the unsolved inequalities that still exist.

The Universe and Human ingenuity is too vast to be confined just to the (not so small) earthly quarters of our existence.

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Further reading:
Nine real NASA technologies in The Martian 
An introduction to the Starch-Statolith hypothesis

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*those that know me from that time, may recall the crush I had on my Plant Physiology teacher’s delicate, long hands so I may not remember a lot of what was taught. OOOOOOOOH… and did I mention his salt and pepper beard?

Cheers, Gisela