On April 26, 1803, villagers in L’Aigle, France watched horrified as 3,000 stones fell from the sky, pummeling the village rooftops. Scientists soon arrived to study the rocks that were very similar to one another, yet very different from rocks found in the surrounding countryside. What were they? Where did they come from? Had the rocks been much larger than 20 to 30 pounds each, they could have posed a serious threat to the village.
400 years ago, Europeans visualized the universe as an unchanging crystalline sphere enfolding everything. Stars were the glory of God shining through holes in that sphere. Planets, the Sun, and the Moon, circled Earth. Earth was at the center of everything, truly God’s Theater in the Round.
But reports kept trickling in to European centers of learning about rocks from the sky. Scientists themselves disregarded the evidence at hand because the existence of such rocks would imply that the heavens were not immutable. Both science and religion remained faithful to the concept of cosmic stasis.
By the early 19th century, attitudes changed. The scientists at L’Aigle worked through various possibilities. Studying 19 separate reports of meteorite falls in Europe, they methodically eliminated various possibilities, such as transubstantiation by lightning, combustion of atmospheric vapors, even the northern lights. Finally, they were forced to conclude that meteorites wander through the heavens until they’re captured by Earth’s gravitational field.
Almost 50 years ago, at age seven, I had my own run-in with objects from outside our world. I attended a day camp for girls. We visited a retired farmer who, after 90 years, still remembered the day when a meteorite nearly struck the home he still lived in. He showed us the boulder that had fallen from the sky. He let each of us handle a fragment of that meteorite. I nearly dropped it, startled by its unexpected weight.
Years later during my space development activist days, I helped set up a poster display that included meteorite cross sections. I fingered the smoothness of the embedded nodules of pure copper, finally fully grasping both the danger and the opportunity represented by the meteor’s density.
Until the 1990s, we didn’t know how much real danger we were in. Earth had been spared from collisions with large asteroids and comets for so long that anxiety over the prospect seemed pointless. However, astronomers recently discovered the existence of over a thousand planet-killer asteroids that regularly intersect Earth’s solar orbit. A collision with a Texas-sized asteroid isn’t necessary to doom all life on Earth. Just a single-kilometer-wide rock will do the trick.
Fragments of Comet Shoemaker-Levi slammed into Jupiter in 1994, opening up gaping holes in it atmosphere. I watched the bombardment on television, awestruck as nature demonstrated the devastating power of kinetic energy delivered at high velocity. One fragment blasted Jupiter with a fireball larger than Earth. Had it hit here, our planet would’ve been vaporized.
Science may one day guide the development of technologies able to stop killer asteroids and comets, vaporizing them with giant focusing mirrors, nudging them out of the way with solar sails, and mining their valuable ores while moving them into a safe orbit with mass drivers. Science sparks technologies that lead to knowledge, feeding back into the development of new science.
This process of learning by picking one’s way through rock fields of uncertainty has much to recommend it. It mates human intelligence and limitations, creativity and traditionalism, and curiosity and ignorance to produce an explanatory system of nature with unsurpassed predictive power.
Religion could never help gather the evidence required for us to concede that asteroids and comets are leftover detritus of the birth of our Solar System. Religion would certainly never suggest that these objects can use our planet for target practice at any time. Why? Religion can only preserve received knowledge. It is forbidden by its core doctrines from engaging in the work of discovery.
Faith is not enough. What we don’t know can kill us. Religion keeps us from learning and knowing. Therefore, it’s more dangerous than science.