For those of you who may not be aware of my shameless stealing, as with the other chapters I am basing this one on the same numbered chapters in 'The Knowledge'. There is little reason to doubt that the chemical elements to be found on exoplanets similar to Earth will be any different to those found here. The universe appears to be pretty much the same wherever you look and it is quite likely that star and planet formation also proceeded along similar lines to our Solar System. So if we take a Sun-like star and find an Earth-like planet in its habitable zone it is more than likely that its chemical make-up will be similar. As mentioned in Appendix A we may need a robotic sample return mission followed by a manned mission to confirm that. Chemists will thus be high on the list of personnel for the early missions.
As on Earth thermal energy needs could be met from a variety of sources. As we would be starting from scratch and with our current knowledge of the effects various fuels have had on our health and the planet should help us make the right choices.
In The Knowledge these two chapters list various substances and materials required to rebuild Earth I and therefore most likely necessary to build Earth II. These comments and all others are based on what we know today and therefore may or may not be relevant at some future date. Extrapolation and speculation will have to wait a while.
We know what we need but how would we find those substances and materials on Earth II ? What can we determine from;
- Earth I or Earth I orbiting satellites
- Earth II orbiting satellites (and how do we get that data back to Earth I ?)
- Earth II ground exploration by robots or humans (ditto)
As far as fossil fuels are concerned we need to find them before we can extract and process them - assuming they exist on Earth II. Geologists to the fore. We may be lucky enough to find for example tar pits or oil rising to the surface of the sea but magnetic or seismic surveys are the more likely method. Interesting website outlining the various forms of energy can be found at http://www.energyquest.ca.gov/story/index.html
Coal
Can be found on the surface where seams have been exposed by rivers cutting valleys or where the overlying strata have been eroded or by drilling. Under the right conditions, peat transforms into coal through a process called carbonization. Carbonization takes place under incredible heat and pressure. About 3 meters (10 feet) of layered vegetation eventually compresses into a third of a meter (1 foot) of coal. So if you can find peat you can perhaps find coal.
Oil and gas
Generally speaking, oil and gas are formed from the organic remains of marine organisms which become entrained within sea-floor sediments. Finding oil and gas is complicated as an extract from http://www.ilo.org/oshenc/part-xi/oil-e ... atural-gas shows;
The search for oil and gas requires a knowledge of geography, geology and geophysics. Crude oil is usually found in certain types of geological structures, such as anticlines, fault traps and salt domes, which lie under various terrains and in a wide range of climates. After selecting an area of interest, many different types of geophysical surveys are conducted and measurements performed in order to obtain a precise evaluation of the subsurface formations, including:
Magnetometric surveys. Magnetometers hung from airplanes measure variations in the earth’s magnetic field in order to locate sedimentary rock formations which generally have low magnetic properties when compared to other rocks.
Aerial photogrammetric surveys. Photographs taken with special cameras in airplanes, provide three-dimensional views of the earth which are used to determine land formations with potential oil and gas deposits.
Gravimetric surveys. Because large masses of dense rock increase the pull of gravity, gravimeters are used to provide information regarding underlying formations by measuring minute differences in gravity.
Seismic surveys. Seismic studies provide information on the general characteristics of the subsurface structure (see figure 5). Measurements are obtained from shock waves generated by setting off explosive charges in small-diameter holes, from the use of vibrating or percussion devices on both land and in water, and from underwater blasts of compressed air. The elapsed time between the beginning of the shock wave and the return of the echo is used to determine the depth of the reflecting substrata. The recent use of super-computers to generate three-dimensional images greatly improves evaluation of seismic test results.
Radiographic surveys. Radiography is the use of radio waves to provide information similar to that obtained from seismic surveys.
Stratigraphic surveys. Stratigraphic sampling is the analysis of cores of subsurface rock strata for traces of gas and oil. A cylindrical length of rock, called a core, is cut by a hollow bit and pushed up into a tube (core barrel) attached to the bit. The core barrel is brought to the surface and the core is removed for analysis.
When the surveys and measurements indicate the presence of formations or strata which may contain petroleum, exploratory wells are drilled to determine whether or not oil or gas is actually present and, if so, whether it is available and obtainable in commercially viable quantities.
Wood has been used as a source of fuel for centuries and, unlike fossil fuels, is a renewable resource. It also has other uses as has been mentioned in other chapters e.g. building houses, boats, domestic utensils and furniture and thus a well forested planet is a necessity.
Chapters 5 an 6 of The Knowledge list other substances which would be required to rebuild Earth and therefore most likely needed to build Earth II e.g.
- calcium carbonate which can be obtained from coral, seashells and chalk. Therefore another good reason for establishing early settlements close to the ocean
- soap is obtained by hydrolising lard with an alkali. Lard we get from animal fat so making use of farm animals for something other than food
- alkalis; potassium carbonate is obtainable from burning wood which is mentioned elsewhere as a key resource and is renewable, sodium carbonate is obtanable from burning dried seaweed (the ocean again)
- ammonia; we can all produce urine which, with the help of bacteria, will produce it (need to identify the right bacteria of course so step forward the microbiologists)
- from wood we can obtain e.g. charcoal, acetic acid, methanol, turpentine, creosote, pitch. However before we can proceed we need to build a device for pyrolising wood. Such a device is described in Chapter 5 of The Knowledge and includes sealed metal compartment so we first need that metal. We can take the pyroliser with u s, construct one from our lander or find the necessary ores locally. One thing leads to another and again demonstrates just how difficult this whole operation will be.
- acids; sulphuric acid can be obtained from pyrite rocks (iron, lead, tin and but you have to find them first, geologist please or perhaps by robotic landers plus sample return missions) plus chlorine gas from brine. Electrolysis and distillation is needed therefore more kit to take or build. Sulphuric acid can then lead to the production of Hydrochloric and Nitric acid
- clay can be used to make pottery and bricks and is found in lakes, ponds or by the seashore.
- limestone is a sedimentary rock formed on the sea bed and blocks of it can be used as a building material. Lime is made from limestone and can be used to make mortar (to bond building blocks together) and cement which is used to make concrete. I suspect that finding the raw materials may prove as difficult, if not more so, than processing them.
To be continued