Question

Colonization of one group of people by another has been a constant theme in human history. Europeans took the practice to a truly global level in the 19th century, imposing their culture and rules on much of the rest of the world, and giving colonization a bad rap in the process.



But from a biological point of view, colonization is perfectly normal. Species compete for habitats and resources all the time, and any species that doesn’t play the game will go extinct. There is no rest for the winners either because the habitat you live in today may not be available tomorrow. Volcanic eruptions and other natural catastrophes can turn your home into a hellscape, and some events — asteroid impacts, supernova explosions, or nearby gamma-ray blasts — can make a whole planet uninhabitable.

It seems prudent, then, for a technologically advanced life form to become a multi-planetary species to avoid possible extinction. That goes for alien civilizations as well. While we (or they) may be able to protect ourselves from certain calamities such as asteroid impacts, there’s not much we can do about a supernova. Colonizing other planets might be the only realistic route to long-term survival.



The ethics of space colonization



That leaves the question of how best to go about it. If we adhere to high ethical standards, we may decide to colonize only those planets that don’t already have indigenous life, so that our survival doesn’t result in their demise. The ethics could get tricky, however. Would we extend that principle to protecting even the lowliest microbes on another planet, even if our own survival were at stake? What if we thought no life existed on Planet Z, but found out after we arrived that it is actually inhabited?



Just how sticky a dilemma this becomes will depend on how common life is in the Universe. If it’s rare, there may be a near-infinite number of planets and moons that are habitable but uninhabited. In that case, it almost seems our duty to spread life — precious rarity that it is — to other worlds. But if there already is lots of life out there, as the Cosmic Zoo hypothesis implies, we will have to tread more cautiously. Don’t worry, though — there should still be plenty of habitable but uninhabited planets to provide a new home.



Would aliens take this same high road when venturing into interstellar space? Contamination may not be a significant problem if the alien visitors are AIs. But a full colonization effort would require biological beings. Luckily, there may be good practical reasons to respect indigenous life, beyond the ethical considerations. The visitors would want to carefully avoid toxic interactions with the indigenous biosphere (think War of the Worlds) so as not to endanger themselves.
According to the third source (Infographic), what is one advantage of building space settlements underground or on the Moon?

A.
Underground bases are more fun for astronauts

B.
Bases avoid exposure to radiation by using thick walls or soil

C.
Spaceships can land closer to the Earth's surface

D.
Moon dust makes construction faster and cheaper

Answer 1

B. Bases avoid exposure to radiation by using thick walls or soil

Explanation: Underground or Moon/regolith-covered habitats use overlying rock/soil as shielding from cosmic rays and solar radiation. Options A, C, and D are not supported by the infographic.