# Preparing human colonists for a desert planet with a red giant

Assuming humanity found a planet they could travel to and was suitable for colonization, how would scientists re-engineer the human colonists for life on this new world?

Planet details:

It's slightly smaller than Earth with 21.5 hour days.

The gravity is 0.7g's.

It circles a red giant, so very little UV but it's close enough to get a fair amount of heat.

The atmosphere is not as thick as Earth with a lower oxygen content, but is still breathable. The 'sea level' air pressure would be about the equivalent of 2,000 meters above sea level on Earth.

The temperature varies widely, with the equator reaching an average of 50 degrees Celsius in the daytime, and an average of 0 Celsius at night. The poles in summer have an average of 30 Celsius in the summer and 5 Celsius in winter, at night it goes below zero and light snow occurs.

The humidity ranges from about 70% during the summer at the poles to as low as 2% at the equator. Water is scarce outside of the poles, with oases, springs, small streams and a few large rivers fed by the combination of mountain springs and rains caused by orographic lift, that eventually form salt lakes and brine marshes in endorheic basins, or dry up leaving vast salt flats along with other mineral run off. There are large underground water reservoirs around the planet, which help plants and animals survive in all but the driest areas.

The poles have broad, shallow endorheic seas that are similar to the Caspian, starting out relatively fresh at one end where the majority of the mountain run off comes from, turning salty in the middle and on the far end turning into brine swamps. Frequent rainstorms particularly in the winter keep the surrounding region humid and well watered.

The equivalent of algae and lichen form the major base of the food chain, and create most of the oxygen, using the salts and minerals for growth. This consequently helps to make the water somewhat fresh for animal life. There are plants as well but outside of the mountains, poles, and rivers they are few and far between.

Most plants are inedible and even poisonous, although some could be used for spice and filling without causing much if any distress to the digestive system. The animals could possibly be used as a famine food, if well cooked to break down the protein bonds.

So with a few decades to prepare the planet for colonization, what exactly would the scientists do to the colonists to help them survive and be comfortable on the planet?

EDIT

I just need some answers about adapting the people to better survive the world. I've got animals, crops, alien animals, etc, covered.

And one last detail. The colonists will primarily be people from the American Southwest and the Thar Desert of India. They both wanted to get off of the overcrowded Earth, they both came from dry regions, and after putting them together in training it was discovered that they wouldn't kill each other.

• So maybe a billion planets in the Galaxy that could be hospitable and we pick a desert planet with dangerously high average temperatures (and what are the summer highs ?). 50 C can be lethal to humans over quite short time scales and that's just your average, not your high. Even 30 C can cause heat stroke and death. – StephenG Jan 28 '18 at 8:01
• The poles are comfortable, as are some of the mountain highlands. More importantly the system has a very large asteroid belt with lots of useful metals. The planet is mostly to act as a rest and resupply area for the space folks, as well as a base for scientists researching the planet. Also while there are plenty of planets out there, many of them have problems such as toxic atmospheres, massive storms, too high of gravity, deadly radiation, etc. For people able to travel through space, a bit of heat that is well within human tolerance outside of the equator, is nothing. – Dan Clarke Jan 28 '18 at 8:13
• If your colonists are planning and able to live and work entirely in a closed environment with a controlled climate, 50C+ is nothing. But a colony that has to live permanently shut off from the planet it's colonizing seems counterproductive. – StephenG Jan 28 '18 at 9:07
• Dan I think you're not getting my point. If the average daytime temperature at the equator is 50 C, then during summer the average will be higher (much higher) and much of a wide band of the planet around the equator (think $\pm 25$ degrees will also have extremely high summer temperatures - probably lethal ones. I think you're underestimating the relationship between average equatorial temperature and average global temperature. On Earth this would be about 27 C and maybe 18 C, and we get 30 C summer peaks as far as Mid to North Europe ! Your 50 C average would imply 50+ peaks. – StephenG Jan 28 '18 at 9:26
• Living underground is a great way to survive deserts. This is and has been done in Australia and the Middle East respectively. Giving the colonists the equipment for underground habitats will be an enormous help to their survival. – a4android Jan 29 '18 at 1:08

Live at the poles.

There seems to be nothing especially challenging about life near the Polar regions: You have described a Mediterranean climate: Warm and dry in summer rain in winter. Enough water for the native Mediterranean plants (dates, citrus, grapes) Drought tolerant grain (millet, sorghum) and with some irrigation effort you can have wheat or barley. If you need animal protein, then goats, but you might be better looking for native animals to domesticate, over time.

You simply wouldn't live near the Equator. On Earth 70% if the land is covered by a massive brine lake that is several km deep. Rather than try to work out how we can build cities in the sea, we just avoid living there.

• I agree, I'm just curious about things like the very low UV output of the sun, and a few things people might want to live in the highlands of the not so scorching deserts. – Dan Clarke Jan 28 '18 at 17:20

Take coconuts, root crops and humans from the tropics. Pigs will tolerate the heat if fed well. Just ensure that you colonise near water sources. Salt is actually used as fertiliser on coconut plantations and they're preadapted to your conditions. A bit of research would probably find others. Dates spring to mind.

If you can fly through space to get them there then the engineering required to use the groundwater efficiently for irrigation should be easy. Probably you could grow any crops you want after a while.

• Coconuts require 55 to 120 litres of water a day, way too much for the environment. Depending on the region they'll grow desert adapted corn, wheat, flax, millet, dwarf apples, pomegranates, dates, most edible cacti, mesquite, watermelon, squash, agave, peppers, cranberries in the salt marshes, and some others. All things that can grow in deserts and can survive drier conditions, except for the cranberries they can grow in briny water. They wanted crops that could survive without technology, they had a planet cut off for a few decades that relied on tech. The results weren't pretty. – Dan Clarke Jan 28 '18 at 8:45
• @DanClarke good point about the water needs for coconuts, but it's just a matter of finding what plants are preadapted to that environment rather than trying to engineer some. The equivalent of google should help them. – Kilisi Jan 28 '18 at 8:53
• why find them, if you can colonize other planets you can engineer your crops. – John Jan 28 '18 at 16:36
• @John because 'don't fix what isn't broke' :-) – Kilisi Jan 29 '18 at 2:11
• every food you eat has been altered from the original stock, it is what we do. heck look at teosinte and corn or bananas as extreme examples. Creating crops that survive in different conditions has saved entire countries from starvation. – John Jan 29 '18 at 14:40

I tried to think of something fantastic like increase the human lung capacity or integrate water storing humps into the human body. But it is easier to bring the most effective tools than to re-engineer humans. The tools I have in mind are biological tools.

Bring llamas

Human colonies on Earth have started with people and their domesticated animals.
I picked llama based on the high temperatures and low oxygen levels stated in the question. Perhaps a camel or goat would be better suited for the colony. Given that it will take a few decades to reach the planet, the animal that lands on the colony will be a bio-engineered hybrid of several Earth animals.

Send crops

Perhaps when the colony ships are halfway along their trip, they send ahead robot gardeners with seeds. The seeds would be of crops that are wind pollinated such as wheat and corn.

Bring pollinators

The question stated that the plants on the planet were poisonous to humans. If there are pollinators on the planet, our plants may be poisonous to them. So bring your own bees.

On the long flight over the humans, animals, crops and pollinators need to adapt to the shifted color spectrum.

Under the red sun, the intensity of blue light will be about a tenth, or less, than the intensity of red. Earth plants absorb about equal parts of red and blue light but need to protect themselves from UV light. Twenty years of selective breed and genetic modification should create new crops that thrive under a red sun.

What about the humans? Adapting to a world dominated by reds and some yellow may be really easy. There is research that shows that seeing blue was a late development in human culture. Could the first generation colonists give up on the color? Perhaps if the colony ship gradually shifts the artificial light spectrum to red over 20 years, no one will notice. If the colonists are asleep and wake up 20 years later on a world colored like hell, there may be some issues.