The Moon has inspired all kinds of experiments, and some of them await our return to the satellite, such as the analysis of excrement and urine from the Apollo program. However, to explore hypothetical cases we can always visit the Kurzgesagt channel, which has already taught us the process of lunar colonization, and the consequences of throwing a nuclear bomb on its surface. What comes next? Basically, asking ourselves what would happen if the Moon fell to Earth…
The best hypothesis about the origin of the Moon is that of the Giant Impact: 50 million years after the formation of the Solar System, a protoplanet the size of Mars struck the proto-Earth, creating a ring of material around our planet, which in turn became the Moon. Obviously, experts have plenty of reasons to doubt the hypothesis, and they continue to explore different scenarios that better explain its existence.
Now, there are two things we know for sure: The Moon is moving away from us (about 3.5 centimeters per year), and to imagine the Moon falling to Earth we need Roland Emmerich (I haven't seen Moonfall yet, and I don't think I will), or a Kurzgesagt video explaining the consequences from a much more precise scientific angle, in a 12-month “journey”. Personally, I'll go with the second option.
What would happen if the Moon fell to Earth?
- During the first month, changes are minimal but constant. The first effects manifest through the tides. As the Moon approaches, the high tide becomes even higher. Floods begin.
- In the second month, the Moon already covers two-thirds of the distance to Earth. With a tide greater than ten meters, global infrastructure begins to fall apart. One billion people displaced. Global failures in transportation of goods, communications, and energy generation. Extreme rationing and chaos.
- In the third month, the Moon's influence ends satellite communication and navigation.
- Between the fourth and fifth months, tides go from 30 to 100 meters, reaching their limit. Now it is Earth itself that begins to feel the gravitational effect of the Moon. Earthquakes become commonplace. Volcanic activity multiplies.
- In the sixth month, the Moon enters the space of geostationary satellites, orbiting Earth every 24 hours. Half the planet remains covered in water. Earth's gravity begins to deform the Moon, causing large-scale moonquakes.
- Between months 8 and 11, the Moon revolves around Earth faster than its rotation. Tides change direction. Volcanic activity and earthquakes continue to grow. The combination of material in the atmosphere and daily eclipses cool the planet. The cold and acid rain kill almost everything in their path. It is the end of civilization.
- With a year of travel, the Moon reaches its Roche limit. Here, Earth's gravitational effect is stronger than the Moon's own gravity. Everything on the lunar surface begins to fall toward Earth. Once past the 10,000-kilometer barrier, the Moon disintegrates, creating a ring around the planet.
The good news is that the apocalypse is over: If the Moon fell to Earth, it would be reduced to dust before impact. The bad news is that there could be negative consequences for the few survivors. If a significant amount of lunar particles falls on the planet, friction could heat the atmosphere, causing the oceans to boil. Another possibility is that the material in orbit blocks even more sunlight. Either way, the price for an Earth with rings seems too high…
