Mars is a hot topic right now. In the last month alone, there have been enough Mars-related announcements to raise the eyebrows of even the most casual observer. Flowing water! Ancient lakes! Human colonies!
None of this is trivial. It opens up the next great frontier in exploration and reveals a universe friendlier to life—our kind, and perhaps other kinds, too—than what some might have expected. It tells us that we are no longer merely the residents of Earth—we truly are citizens of the cosmos.
Such developments may not seem like much, but they have much wider implications. To really understand the ramifications, however, you have to go all the way back to the beginning of astronomy.
Originally the observation was made that the stars were fixed in the sky, with a curious few (Mercury, Venus, Mars, Jupiter and Saturn) acting as “wandering stars” or “planets”. By the time of the ancient Greeks, it was fairly well established that Earth was a sphere about which the Sun, the Moon and the five planets revolved—a model later codified by the Greco-Egyptian astronomer Ptolemy in the second century. And that’s the way things stayed for 1400 more years.
When things started to change was in 1543 with the publication of the book De revolutionibus orbium coelestium by Polish astronomer Nicolaus Copernicus. De revolutionibus detailed a heliocentric (i.e. Sun-centred) model in order to explain apparent planetary motion; by implication, it also contained the “dangerous idea” (to borrow a phrase from Daniel Dennett) that humanity was not at the centre of the cosmos. We were not privileged. Needless to say, the concept didn’t take off.
If you want to really trace the beginning of the so-called “culture wars”, they all really start with Copernicus. The heliocentric model directly challenged the prevailing paradigm, pitting the conservative establishment against the more progressive thinkers of the time. Martin Luther staked out his position early, writing about “an upstart astrologer who strove to show that the earth revolves, not the heavens or the firmament, the sun and the moon” despite the fact that, per the Christian Bible, “Joshua commanded the sun to stand still, and not the earth.”
So challenging was the paradigm shift promised by heliocentrism that there was an attempt to reconcile the Copernican mathematics with the apparent “fact” that the Earth was at the centre of the universe: the Tychonic system of the late 16th century had the five planets revolve around the Sun while the Sun itself, the Moon and the stars all revolved around the Earth.
The Italian astronomer Galileo Galilei, however, was able to see beyond the received wisdom of Earth’s privileged position in the universe. He argued that not only was the Copernican model a physical reality (thus removing Earth from its privileged position), but that Scripture should be reinterpreted to fit that reality.
The Catholic Church were not particularly pleased to hear such arguments: in 1616, Galileo was ordered to “abandon completely” the heliocentric model as physical fact; meanwhile, Copernicus’ De revolutionibus was banned. Following the publication of Galileo’s book Dialogue Concerning the Two Chief World Systems in 1632, the astronomer was found to be advocating the full adoption of the Copernican model despite explicit instructions to the contrary; his book was, like that of Copernicus, banned by the Church while he himself was found to be “vehemently suspect of heresy” and sentenced to house arrest. He died in 1642.
It was already too late, of course. Between Galileo’s order to abandon the heliocentric model and his sentence to house arrest, German astronomer Johannes Kepler published his laws of planetary motion, which were then systematically derived by Isaac Newton in 1687. In 1758, the ban was lifted on books advocating for heliocentrism—better late than never, you might say, since it only took 70 years after Newton’s work and 215 years after Copernicus’ work for the Church to acknowledge reality.
Heliocentrism is most problematic because it suggests that the Earth is not separate to the planets but is, in fact, one of many. If you remove the Earth’s special place in the universe, you undercut the very foundation upon which the establishment rested at the time: it implies a reality free from hierarchical order, where no one and no thing has a natural right to privilege. The Church knew that once people started questioning Earth’s privileged position, other questions would follow.
They weren’t wrong. In 1859, Charles Darwin published On the Origin of Species, and suddenly not only was Earth merely another planet, humans were merely another animal. Albert Einstein then decided in the early 20th century to take the key idea in both Darwinian natural selection and heliocentrism to its logical conclusion by revealing that relativity is, in fact, part of the very fabric of the cosmos.
This is why social conservatives still argue loudly for Creationism being taught in school: without it, they lose any claim of a natural right to privilege. They lose any solid ground upon which to rest their arguments. If you’re arguing against same-sex marriage, for example, all you have left is a claim that “It’s always been this way” (which is false, but never mind the facts).
Now with the Kepler space observatory, we have discovered many worlds beyond our solar system. For almost 500 years, evidence has continued to mount that we are simply one form of life on one planet in one solar system in one galaxy, and there are at least 100 billion other galaxies where that came from—the “mediocrity principle”.
When we look to Mars—our next-door neighbour, no less—and find flowing water, we are really finding significant evidence for our own mediocrity and thus a lack of any natural right to privilege. Once you get people excited about discussing other Earth-like planets and the possibility of life elsewhere, you claim the narrative against social conservatives.
Space exploration has the power to transform society—even society here on Earth—like nothing else.