TRAPPIST-1h isn't a challenging planet to terraform, but we don't know if it has an atmosphere or a magnetic field. It was discovered by the Spitzer Space Telescope.
Terraforming TRAPPIST-1h[]
Trappist 1h is a challenging place to terraform, because it orbits a star different then our Sun. Its hosting sun is a M - type star, more exactly a flare star, producing a light that is not compatible with Earth-like plants.
Still, in many aspects, conditions on the planet could be similar to Mars and the technologies needed should also be similar to Mars.
TRAPPIST-1h isn't a challenging planet to terraform, but we don't know if it has an atmosphere or a magnetic field. It was discovered by the Spitzer Space Telescope.
TRAPPIST-1h is a rocky planet, with a radius of 0.715 Earth radii and a mass of 0.086 Earth masses. Its density is 1.297 grams per cubic centimeter and it has a gravity around 0.168 times Earth's gravity, which is similar to the Moon's gravity. It has an equilibrium temperature of 169 K, about the same as Antarctica on Earth. It has an orbital period of 18.764 days and a semi-major axis of 0.063 AU. TRAPPIST-1h is at the snow line, meaning that it is at the equivalent distance from its star as Mars is from the Sun. However, it could still have liquid water if it has a hydrogen-rich atmosphere. If it is an icy planet, it could also have a subsurface ocean caused by underground volcanoes.
Surprisingly, as we will see in later sections, Trappist 1h is not suitable for Earth-like plants. Luminosity is mostly in infrared, with red hardly matching the needed amount for plants to support photosynthesis, while blue light is far too dim. We will have to develop plants able to survive only with red light or to use infrared as their source of energy. Genetically modified plants will be at the heart of the food chain. In such conditions, animals will have to adapt (or even be made by genetic engineering to adapt in these conditions). Humans will also need to be transformed, to survive with the kind of food that plants and animals will provide them with. In addition, the star will occasionally blow deadly flares. Plants, animals and humans will have to adapt to these as well.
We must acknowledge that Trappist is not an exception. Most of surrounding stars are M - type stars and a high number of them (if not the majority) are flare stars. So, conditions encountered here, will be found in many places of the Universe, if not in most of solar systems.
The Star[]
- Mass: 0.089 (Sun = 1)
- Radius: 0.121 (Sun = 1)
- Luminosity bolometric: 0.000522 (Sun = 1)
- Luminosity visual: 0.00000373 (Sun = 1)
- Temperature: 2511 K
- Rotation period: 3.295 Earth days.
The hosting star is a dim M - type star, red dwarf. Its spectral class is M8. It is also known as 2MASS J23062928-0502285 and it is located 39 light years from Solar System.
M - type stars have some common properties. Most of the light they produce is in infrared, most of visible light is in red. The star produces little light in blue spectra. Dim M - type stars (spectral classes M5 to M9) are known to be flare stars. This is a major problem for any planet orbiting. The faster the star rotates, the more often flares will occur. Trappist is known to rotate fast (3.295 Earth days), meaning that flares are common.
During a flare event, the star re-arranges its magnetic field. Another flare star, UV Ceti, is known to increase its luminosity 75 times in only a few minutes, then fall back to its previous luminosity levels in another few, additional minutes. Flares are followed both by plasma ejections (and powerful Stellar Wind) and massive increases in brightness (that also come with deadly emissions of UV and X rays). Flares can, in time, erode the atmospheres of any planet. Because all Trappist planets are very close to the star, they are all exposed to flares.
Luminosity Parameters[]
Is there enough light to support plant life? Based on luminosity data, we can calculate the Solar Constant. Results are like this:
- Ks (total energy output) = 23.1
- Ksv (total visual light) = 0.165
Using Stellar Parameters, we can calculate, based on temperature, what is the spectral shape of Trappist. Very important is to see the amount of red and blue light, because Earth plants will need both types of light to survive. This is the data:
- Red light: 68.4, Ksr = 0.165
- Yellow light: 6.13, Ksv = 0.024
- Blue light: 0.220, Ksb = 0.00530
Earth-like plants cannot survive if the light constant, either in red or in blue, is below 0.002 (see Plants on new worlds for details). With this data, we can calculate the habitable parameters around Trappist:
- For Earth-like plants, 1.62 million km (imposed by the weak blue light)
- For plants able to use only red light, 9.08 million km
- For plants able to use only infrared light: 107 million km.
Based on this data, we can conclude that, in the Trappist system, not all planets will be habitable for Earth-like plants:
planet distance plant life nomenclature million km expected b 1.73 Earth-like (?) c 2.37 red light d 3.33 red light e 4.38 red light f 5.76 red light g 7.01 red light h 9.27 red light (?)
As one can see, Trappist h lies in a point where genetically modified plants, suitable for red light, will hardly get enough light to survive.
The Planet[]
Trappist 1h orbits is the furthest known planet of the Trappist system. This is what we know about it:
- Distance to the star: 9.27 million km
- Diameter: 9860 km
- Mass: 0.331 (Earth = 1)
- Orbital period: 18.77 Earth days.
Based on this, we can calculate other, useful data:
- Gravity: 0.553 (Earth = 1)
- Density: 3.94 kg/l
- Stellar gravity: 23.2 (Earth = 1)
- Sphere of influence (Hill sphere): 0.144 million km
- Solar Constant:
- bolometric: 0.269
- visual (red): 0.00192
- visual (blue): 0.0000617
Trappist 1h appears to be a planet slightly larger then Mars. Its density is what we would expect for a planet with a rocky core. Mars has a density of 3.95. So, if it has water, certainly it is not in a too large volume.
The strong gravitational pull from the star (23.2 times higher then for Earth) suggests that Trappist 1h is tidal locked. Otherwise, it will experience significant tidal heating and volcanism. Its small Hill sphere (144000 km) suggests that there are no moons. If there are, they should be small and orbit very close to the surface.
We know nothing about the surface parameters. If Trappist 1h has an ice-coated surface, then its albedo will be smaller, accounting for much lower average temperatures. Still, if its surface is dark, like the Moon, then we can expect surface temperatures to be higher. It was suggested that Trappist 1h has a surface temperature of -104 C [1]. Using Planetary Parameters and formulas for Temperature, we get -92.9 C. Since we don't know the albedo, we cannot calculate an accurate temperature.
Atmosphere Erosion[]
Trappist 1h appears to be able to hold an atmosphere (see below, the simulation). However, we must not forget that it orbits a flare star. If a flare hits the planet, it will erode part of its atmosphere. During flare events, the solar constant can increase even 100 times. When this happens, temperature can rise to +261 C. In addition, this will come with powerful jets of UV and X rays and charged ions. On a long time scale, this will remove an atmosphere, leaving behind only a tenuous layer of gas.
Even if Trappist 1h has a magnetic field, it is questionable, at its close distance to the parent star, what will be the chances for a flare to be stopped.
Flares of red dwarfs are comparable in size with flares of the Sun. The main difference is that these stars are very dim and the Habitable Zone is too close.
Surface Composition[]
Water, at Trappist 1h's orbit appears to be solid. Still, water molecules can sublimate, forming a tenuous atmosphere, which is removed by flares. It is questionable if other gasses will remain for long (like carbon dioxide, nitrogen or methane). Technicians will have to look on the surface for possible tholins and ammonia compounds in order to build an atmosphere. It is not known if Trappist has a Kuiper Belt. If it has, additional water and volatiles can be brought from there. If not, things get very complicated.
Since Trappist 1h is a rocky planet, we presume it has all non-volatiles needed for plant and animal life, in various compositions.
Possible Tidal Locking[]
Trappist 1h is likely to be tidally locked. As a result, there is a permanent day side facing the star and a continuous night side facing away.
Terraforming Process[]
Main article: Planetary Terraforming And Colonization
The terraforming of Trappist 1h is a complex process, that will involve significant efforts.
Research Phase[]
The first phase of any terraforming process will be the research phase. During this period, manned and unmanned ships will be sent to the planet, to conduct surveys and measurements. A feasibility study needs to be done, showing if terraforming costs can be covered by the benefits expected.
This will require the construction of a Research Station on the surface. Many manned and unmanned missions will examine the surface, will take sample rocks and will analyze the environment. If needed, additional probes will be sent to the possible Kuiper Belt that Trappist 1 might host, to see if it is possible to bring in water and volatiles.
Preparations[]
If the feasibility study confirms that Trappist 1h can be terraformed, a Terraforming Plant needs to be built on the surface. This is the central piece, where most chemical transformations will be conducted. Like in any other cases, the terraforming plant needs to be huge.
Creating Atmosphere[]
Main article: Creating An Atmosphere.
Because Trappist 1h is losing its atmosphere during flares, we presume that there is not much left. Technicians will have to supply one somehow.
Basic data for an Earth-like atmosphere:
- Ground average temperature: 15 degrees C
- Surface pressure at sea level: 1
- Atmosphere total mass (Earth = 1): 1.04
- Atmosphere breathable height: 14.9 km
- Atmosphere total height: 44 km
- Ground average temperature: -100 degrees C
- Surface pressure at sea level: 1
- Atmosphere total mass (Earth = 1): 0.807
- Atmosphere breathable height: 11.6 km
- Atmosphere total height: 34 km
- Combined parameters:
- Atmosphere total mass (Earth = 1): 0.93
- Atmosphere breathable height: 14 km
- Atmosphere total height: 38 km
From here, one can see that Trappist 1h will require an atmosphere with a similar volume to Earth's, which is 5.1480×10^18 kg. By comparison, this is 500000 times the mass of Rosetta's comet 67P.
An atmosphere might have a huge volume, but for a planet, it is not too much mass. Earth's atmosphere weights like a layer of 10 m thick of water, covering the whole planet. Trappist 1h will certainly have this amount of frozen water (to produce oxygen) and trapped ammonia (to produce nitrogen) in its rocks.
Adjusting Temperature[]
Main articles: Adjusting Temperature and Temperature.
Because Trappist 1h orbits slightly outside of the habitable zone, it will need Greenhouse Gases. The Greenhouse Calculator shows us that we will need 0.417 kg of sulfur hexafluoride per square m. This is not a big amount. Sulfur is common in the Universe. Fluorine is more sparse, but still in enough quantities for what we need.
The target will be to secure an average temperature of 15 C.
Greenhouse gasses trap infrared light. However, since the star emits most of its light in infrared, it is questionable how efficient any greenhouse gas will be.
Creating Oceans[]
Main article: Creating Oceans.
This will be the hardest challenge of all. Because of flares, we presume that Trappist 1h lacks water in large enough quantities. The only solution will be to bring water from somewhere else. If Trappist has a Kuiper Belt, that is the source.
We know nothing about planet's Geography. If it has large mountains and deep depressions, the amount of water will be huge. Still, if it has plains, we will need far less water.
Earth's oceans weight 1.4X10^21 kg, which is nearly 1.5 times the mass of Ceres. Still, Trappist 1h is far smaller. Probably we will need the same mass of water as the asteroid Vesta.
If Trappist 1h has a Kuiper Belt, the problem might be solved. By diverting a few large ice asteroids, we can get the water we need. This will automatically create an atmosphere, because there will certainly be many volatiles trapped in the ice.
If they are large, the diverted icy asteroids need to be broken apart into smaller pieces. Also, by controlling the impact places, we can ameliorate the Geography, breaking down natural obstacles like mountain ranges and creating canals that will merge oceans.
We must be very careful what kind of ice we bring. If we send in water with too much deuterium, living organisms will suffer. Also, if the ice contains too many gasses, it will dramatically affect the atmosphere. It will be good to break asteroids into small pieces. This way, gasses will sublimate faster, letting only ice and solid debris behind.
If there is not enough water to be shipped, then we will have a Desert planet.
Ameliorating The Atmosphere[]
Main article: Ameliorating The Atmosphere.
After creating oceans, a primary atmosphere and increasing the temperature, we can focus on ameliorating the atmosphere. For this, we will need to do a lot of transformations:
Carbon dioxide is needed in small amounts, but most of sure, at the beginning, it will be in high amounts. We can insert genetically modified plants, that might be developed in future, to transform carbon dioxide into Atomic Carbon and free oxygen. As well, we can use technology for this process, even if this will be far more expensive.
Oxygen can be produced from water via electrolysis or from carbon dioxide by plants.
Nitrogen could be supplied from comets, could exist on the planet (trapped in rocks or in the atmosphere) or could be produced from ammonia sent from comets.
Methane is an unwanted gas. We will like to get rid of it, by creating lightning and burning it in the atmosphere.
Hydrogen will result from water or will be shipped from comets. This gas is light and will escape into space.
Other gasses are unwanted, like sulfur dioxide. They will interact with other gasses, with rocks or will be artificially removed by the terraforming plant.
Ameliorating The Geography[]
Main article: Geography.
We have no idea what is on the surface. There are 3 dominant Geographic features on celestial bodies:
- Geographic Pattern - Craters - surface covered with craters
- Geographic Pattern - Tectonic - surface covered with mountains, faults, rifts and volcanoes, including volcanic plains
- Geographic Pattern - Erosion - surface eroded by water (or other fluids) and by wind.
It is very important to ameliorate the Geography. It is good to avoid making endorheic basins. Lakes might need to be drained, rivers to be dug, mountain ranges to be blasted to allow air currents to pass, deep canals to connect oceans and so on.
Much of the work might be done during previous steps, when water was delivered to the planet by comet impacts.
Ameliorating Soils[]
Main article: Minerals.
There is a high chance that Trappist 1h will have a different chemical composition. Some elements might be in excess, while others might be lacking. Technicians will have to solve this problem. Chemical elements in excess can be neutralized by chemical reactions (and for metals, by changing their oxidation state). elements that are lacking can be replenished from mining or from an asteroid.
This process will take some time. The best way to do this, is by airplane, dropping chemicals from low altitude.
Insertion Of Life[]
Main article: Insertion Of Earth-like Life.
Trappist 1-f lacks blue light and even the red light is not in enough amounts. Because this, we have to re-think the entire biosphere.
Earth-like plants will not survive. Genetically modified plants, able to use only red light (or better, to use infrared light) for photosynthesis, will be the only plants able to survive. For this purpose, we have to develop a different pigment then chlorophyll and make plants produce and use it.
Artificial plants will never cover the same biodiversity found on Earth, but will still be a source of food for various animals and for humans. Probably not all animals will adapt to this.
Colonization Phase[]
Colonization process is what will naturally occur after terraforming.
Limits[]
For Trappist 1f, the Population Limit has various values: 2987
- Population limit:
- For plants using red light: 2.90 million people
- For plants using infrared light: 40.6 million people
- Land farming capacity:
- Plants using infrared light: 80.7 people per square km
- Plants using red light: 0.576 people per square km
- Largest city without affecting the environment: 162000 people.
Another major problem will be the flares, which will dramatically disrupt climate.
Early Colonization[]
Main article: Early Planetary Colonization.
The first to come will be scientists and technicians that will work during research and terraforming phases. Even before terraforming is completed, some settlers might already come. However, the planet will be opened for settlers only after terraforming is completed.
Trappist 1h will offer some challenging aspects. Plant life will be different, made of artificial species. Because of this, it is plausible that also the humans that will live there, will not be like us (see Future races for details). They will use as food only genetically modified plants, since no classic Earth plant will survive there.
After terraforming will end, the planet will have some limited infrastructure. This will include:
The terraforming plant is where all terraforming processes occurred. It will have a large space base, that can be used by settlers and industrial corporations. The place where scientists and technicians lived, will be the first city. It will have apartments and all facilities needed to live in. Also, the terraforming plant had huge nuclear generators that provided the needed energy, they should still be functional. In addition, many more facilities should still be there.
Infrastructure. Terraforming requires large amounts of materials to be transported over the planet. Mainly during soil amelioration, minerals had to be mined and refined, transported, processed and added where they were needed. Water transport and railways are the cheapest way to move large amounts of cargo around. In addition, roads (dirt or concrete roads) and airstrips should also exist. All these facilities, once terraforming is over, will continue to be used by the settlers.
Advanced Colonization[]
Main article: Advanced Planetary Colonization.
Once population increases over a certain limit, infrastructure needs to be extended, to give access to new land. Energy generation will require construction of new power plants. During this phase, the economy will grow.
As shown above, for environmental reasons, there are some restrictions for population limit and population density. During this phase, in some areas, population density might reach critical limits, mainly in cities. People will be advised to move to remote places. Still, there will be enough free land. In some areas (for example, around the former terraforming plant), population density limit will be achieved and urban development will reach its limit. However, there will be large areas where colonization will still be at the beginning. In order to do so, a different taxation protocol is needed. People in crowded areas will have higher taxes, while in remote areas, it will be a tax-free regime.
Colonization At Apogee[]
Main article: Planetary Colonization At Apogee.
When this will happen, the planet will be close to population limit. At this point, the state will have to close its borders, to limit immigration. A good decision will be to finance terraforming of other planets for creating new colonies. The new colonies on other planets will benefit from a tax-free regime, to motivate people to move.
Decline[]
Main articles: Planetary Overpopulation andPlanetary Colonization Decline.
If population increases above a safe limit, the ecosystems will not be able to resist. Once overpopulation occurs, if the state does not have money to terraform other worlds and relocate people, the economy will enter a dangerous spiral to collapse. If planetary equilibrium is broken, then a lot of environmental problems will occur one after the other, down to a point where people will start moving out on their own or a part of the population will die.
Simulation[]
How would a terraformed Trappist 1h behave like?
Maintenance[]
Main article: Maintaining a terrafomed world.
What natural hazards can affect the terraformed planet like Trappist 1h? First of all, the atmosphere will be exposed to flares. Let's do some math and determine atmospheric stability for certain molecules.
- Atmosphere stability for oxygen molecules: **Earth's gravity (15 degrees C): 4.116
- Trappist's gravity (15 degrees C): 6.29
- Trappist's gravity (-100 degrees C): 3.78
- Trappist's gravity (+250 degrees C): 11.42
- Atmosphere stability for water molecules:
- Earth's gravity (15 degrees C): 7.320
- Trappist's gravity (15 degrees C): 11.19
- Trappist's gravity (-100 degrees C): 6.72
- Trappist's gravity (+250 degrees C): 20.31
- Atmosphere stability for hydrogen molecules:
- Earth's gravity (15 degrees C): 65.88
- Trappist's gravity (15 degrees C): 100.7
- Trappist's gravity (-100 degrees C): 60.5
- Trappist's gravity (+250 degrees C): 182.8
Note: A value smaller then 10 means the atmosphere is stable for millions of years. A value between 10 and 100 indicates stability for at least thousands of years. This does not include effects from solar winds.
15 degrees C is the average surface temperature. -100 C is the temperature expected in the upper atmosphere, which is not protected by a greenhouse layer. 250 C is temperature expected during flares. One can clearly see that oxygen (and also nitrogen, which has a similar mass) shows stability for every moment except flares. Water molecules can still be considered to have stability, with the exception of flare events.
The hosting star has a far smaller UV radiation then the Sun, except during flares. This radiation can disintegrate water molecules. Hydrogen will then escape into space.
Conclusion: Trappist 1h has an atmosphere that shows similar stability with Mars (see Mars Simulation for details). During flares, speed of gas molecules can occasionally reach escape velocity. Still, it appears that the atmosphere will have stability for a long time, compared with a human civilization.
Unfortunately, we have no formula that can indicate how much gas will be lost during flares. Even today, world leading experts don't agree on models for planets in the Solar System.
Climate Simulation[]
Main article: Climate.
There is a high chance that Trappist 1h is tidal locked. If not, it will be exposed to a huge tidal stress.
If the planet is not tidal locked and has zero axial tilt, we get the following values:
- poles: 11 C
- 75 deg: 11 C
- 60 deg: 14 C
- 45 deg: 15 C
- 30 deg: 16 C
- 15 deg: 17 C
- equator: 18 C
However, if the planet is tidal locked, things are different. Let's assume that the South pole is in the center of the illuminated hemisphere, always pointing to the sun, while the North pole is in the center of the cosmic hemisphere. Temperature values become:
- South pole: 21 C
- 75 deg S: 20 C
- 60 deg S: 19 C
- 45 deg S: 18 C
- 30 deg S: 16 C
- 15 deg S: 13 C
- equator: 10 C
- 15 deg N: 8 C
- 30 deg N: 5 C
- 45 deg N: 2 C
- 60 deg N: -1 C
- 75 deg N: -3 C
- North pole: -6 C
As one can see, it will not be too hot at the equator, but on the cosmic hemisphere, temperatures will reach freezing point. Water will freeze and accumulate there. In order to maintain an equilibrium, we can increase the amount of greenhouse gas, keeping temperature with 10 degrees C higher. This will ensure that ice will not accumulate.
For a Tidal Locked Planet, climate is extremely stable and highly predictable. Winds will constantly blow in the same direction, mixing air in the two hemispheres. The result is an equivalent Earth climate. We will have similar climate regions like on Earth, but without seasons. It will be an endless day, without day-night or seasonal climate oscillations.
Flares.
The major thread will be flares. Scientists will be able to speculate when a flare will occur and ring the alarms.
During a flare, luminosity will increase up to 100 times in only a few minutes. It will not only be visible light, but also UV and X radiation. Charged particles, which travel with around 1000 km/s, will reach the planet in 2 to 3 hours later, creating huge auroras and even reaching the surface. This event will be clearly visible during day and will also affect all wild life and all electronics.
During flares, fires will start in forests and on pastures, as vegetation will sometimes be overheated. Many animals will die, unless they manage to get fast into water or underground. Humans will also have little time at their disposal to save themselves. People will have to get out of their homes and hide in underground chambers.
On the climate, flares will have a huge impact. Wind currents will be altered and massive storms, even hurricanes, can be produced, as the planet is heated too much in a very short amount of time.
Most of flares will not directly hit the planet, but still, the massive increase in brightness will have a devastating impact on all living organisms. However, if a flare directly impacts the planet, the effect will be huge, catastrophic. It will not have the power to remove a significant part of the atmosphere, but it can have the power to barbecue a living organism in two minutes.
Conclusion[]
Trappist 1-h will be a very interesting place to live. It might not be hospitable for classic humans, as only genetically modified plants will be able to survive in the dim, red light and as occasional flares will hit its surface.
Still, it will offer a mild climate and many facilities that will be appreciated by those future races that will adapt to its environment.