Much ink has been issued regarding the continuation of space exploration — the Moon and Mars, mostly. Before we take that next step, there are several critical factors which need to be considered. With a background in astronomy, I hope to present some useful information.
First, the Moon:
Although our lone satellite is close enough to visit without too much difficulty. we now know that it is composed of rock mostly identical to rocks on the surface of the Earth — no diamonds, no gold, just ordinary rock. One small item unique to the Moon’s regiolith is He3, a potential fuel for nuclear fusion. This is rather rare on Earth, but the quantities available on the Moon will always be much smaller than our needs, and the means to use it haven’t even been considered yet.
Everything lunar colonists would need to survive would have to be shipped from Earth, at least at first. There apparently is some ice in the bottom of craters near the lunar north pole, but we don’t know how much. This could be used to produce rocket fuel and oxygen for breathing. All food would have to be produced in pressurized tunnels under lights, recycled, or shipped in.
The surface of the Moon would be dangerous at all times because of the nonstop rain of nuclear particles emitted by the sun. This solar wind mostly doesn’t reach the surface of the Earth due to our thick atmosphere and guardian magnetic field. The Moon, without either of these, takes the full impact. And if a solar flare were to strike the Moon full force, anyone unprotected on the surface would live only a few minutes. For this reason, it might not be feasible to live on the surface at all.
The idea of establishing bases on the Moon is a dangerous concept. Any scientific research made possible would be a benefit, but “bases” sounds a bit like “projecting American power.” Any involvement of the our military in space could only touch off an arms race — a great way to sink endless amounts of money into something we dare not use.
All of this would cost prodigious amounts of funding we don’t have. Would a spectacular view of the Earth and some bragging rights be worth it? If the scientific knowledge is beneficial, we have the means to accumulate as much as we need with unmanned missions, more cheaply and with less risk. In such a potentially hostile environment, only on missions which a robot could never perform should we risk human lives.
As to the Moon as a jumping off place for deeper missions, say, to Mars:
This is the dream, isn’t it? Another planet to move to, either to offload surplus population or as a safe retreat for when the asteroid of doom strikes the earth. We just need to terraform it, right? However, Mars has a few technical problems which militate against its being a habitable planet.
Mars has next to no atmosphere now for two simple reasons. The first is that the planet is too small to have sufficient gravity to hold on to much, just a bit of CO2. The solar wind has blown away what else there used to be. Any attempt to recreate an atmosphere and warm the planet would have constant attrition to deal with, requiring endless restoration. Even if the planet were bigger, the result would be the much the same due to the lack of a planetary magnetic field such as possessed by the Earth. This great, invisible shield is our safeguard against cosmic rays and the solar wind, and if it did not exist, life on Earth probably would still live exclusively in the oceans. Lacking one, Mars could never have a permanent atmosphere other than the few wisps we find there now.
We now know rather well what Mars is composed of. Due to the lack of plate tectonics, the surface is not enriched by outpourings of pristine material from deep within the planet, as it is on Earth, and the few volcanoes stopped operating billions of years ago.. The geology of the surface has been merely rearranging what was originally there for several billion years, and almost none of it is any different from what we have here on Earth.
The idea that we could ship surplus population to Mars is preposterous. It requires 1000 Lbs. of fuel to lift ONE pound of payload into orbit. Further, if we wanted to fill up a distant planet, it would make more sense to ship very few active breeders and let them produce the population surplus on site.
It has been said that we need to step into space for survival of the species, as in “before we blow ourselves up.” I cannot be quite so pessimistic since I was here during the cold war, the last time blowing ourselves up was a real possibility. Reason prevailed, and we survived that.
A similar idea, that we need to get off the planet before the big asteroid wacks us needs to be evaluated carefully. The chance that some dire fate could fall on us ever is meaningless by itself; we need to consider how often it is likely to occur and respond in proportion to the real risk. An over response looks a lot like panic mongering. Would you even place a bet when the odds were ten million to one?
Probably the most important discovery to come from the Space Program is this: We live on the only sweet spot in the whole solar system. The search for life throughout the other planets and satellites has become basically a hunt for microbes. Although we now know that planets are abundant in our galaxy, having the right conditions for a long enough time to give rise to complicated life forms such as ourselves may be rather more rare. (4 bil. yrs. for us) Until we have the means to travel to other stars, most of which will likely not have what we need, we have just this “third stone from the sun”.
I may have stepped on someone’s dream in this blog. If so, I am sorry. At a time when we are considering our initial steps toward the stars, we need to evaluate each step carefully. It is always best to keep one eye on the horizon while the other looks to heaven. As an an astronomer, I am wholly in favor of space exploration, but only where it can be shown how the benefit will outweigh the cost, especially where lives would be at stake. We have more than enough important causes needing money on this planet and in this country without throwing billions into manned missions at high risk for questionable gain.
However, if you are looking for a planet to upgrade to full habitability, I have one for you. So far, we Humans have ruined almost 20% of the usable land originally available to us on this ball of rock, mostly through exploitative land use and bad farming practice. Not a good track record.
If we want a planet to terraform, we should start with the Earth.
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I much appreciate the assignment to Community Spotlight. I feel this is a topic which needs to be explored thoroughly, and I am hoping for more of the excellent commentary I have seen so far.