Photo by Romain Kamin

Wayne Scott Harral presents a very realistic and grounded take on how a colony on our lunar neighbor might function in Moon Luck, but for real life to catch up, let’s learn how the moon was born.

Gazing at the natural satellite that dominates the night sky, one can’t help but wonder about its origins. The Moon, Earth’s faithful companion, has witnessed the rise and fall of civilizations, bathed countless people in its glow, and inspired countless myths and legends. 

But how did our constant celestial dance partner come to be? Buckle up, space voyagers, for we’re about to embark on a journey through the eons, unraveling the Moon’s fiery and chaotic birth.

Promise the Moon

Rewind 4.5 billion years (Yes, our lunar neighbor is that old). Our solar system was a swirling disc of dust and gas, a cosmic cauldron birthing newborn planets and asteroids. Earth was just a nascent ball of molten rock that was slowly taking shape. 

But its path wouldn’t be a solitary one.

Enter Theia, a Mars-sized body hurtling through this cosmic bar. In a celestial game of billiards, Theia met Earth with a colossal impact, unleashing an unimaginable amount of energy. This wasn’t a gentle bump; it was a head-on collision that vaporized rock, melted mountains, and sent shockwaves rippling through both bodies.

The aftermath was, to say the obvious, apocalyptic. Both Earth and Theia were largely shattered, their molten innards spewing into space like two kids hurling sick. But from this cosmic carnage, something new was birthed. The heavier debris from both bodies sank towards the center, recreating a larger Earth. Meanwhile, a swirling disc of ejected rock and vapor, rich in Theia’s material, orbited the new Earth—the seeds of our lunar neighbor were sown.

This disc, known as a circumplanetary disk, wasn’t static. Gravity, ever the celestial puppet master, pulled at the swirling debris, slowly shaping it into a cohesive mass. 

Collisions between larger chunks, the gravitational tug-of-war between Earth and the disc, and the sheer force of its own rotation—all these factors played a role in shaping the nascent Moon.

Our Lunar Neighbor Was Born!

Our newly formed lunar neighbor was far from the tranquil Moon we see today. The immense gravitational forces and radioactive decay within its core generated unimaginable heat. The Moon became a molten ball of magma, with its surface a churning sea of lava. Heavier elements sank towards the center, forming a metallic core, while lighter elements rose to the surface, solidifying into the Moon’s rocky crust.

As the Moon cooled, massive volcanoes erupted, spewing molten rock onto the surface. These titanic eruptions dwarfed anything seen on Earth and formed the lunar highlands: the ancient, cratered regions that dominate the Moon’s face.

Around 4.2 billion years ago, a period of intense meteorite bombardment unleashed another dramatic chapter in the Moon’s story. The impacts vaporized water ice trapped within the lunar rock, creating a temporary but vast lunar ocean. This “ocean” covered much of the Moon’s surface, potentially reaching depths of hundreds of kilometers. However, due to the lack of a thick atmosphere and the Sun’s scorching heat, this lunar ocean eventually evaporated, leaving behind the vast, dry plains we see today.

The Moon’s sculpting, however, wasn’t over. Asteroids and meteorites continued to bombard the lunar surface, leaving behind the craters that scar its face. Some impacts were so colossal that they created massive basins, like the South Pole-Aitken basin, one of the largest known impact craters in the solar system.

A Twin to Our World

Despite their distinct appearances, Earth and the Moon share a common origin story. Isotopic analysis of lunar rocks brought back by Apollo astronauts reveals a striking similarity in their composition, supporting the giant impact theory. The Moon isn’t just a celestial companion; it’s a twin of Earth flung off because of a cosmic dance of destruction and creation.

Looking for a story set on our lunar neighbor? Moon Luck by Wayne Scott Harral presents a very realistic and grounded look at how a lunar colony might function and the issues that abound.