Blurs

The Moon seems permanent. It rises, it sets, it controls the tides. It has been there throughout human history. But the Moon we see today is not the Moon that Earth had in the distant past. Our satellite is slowly moving away from us. At the same time, Earth's rotation is gradually slowing. Go backwards far enough and the relationship between Earth and Moon becomes dramatically different. The Moon would have been closer, the tides would have been stronger, Earth would have spun faster. Days would have been shorter. And the night sky would have looked completely unfamiliar. But this raises a more intriguing question. Could the young Earth have had a Moon that was fundamentally different from the one we know today? Not necessarily a different moon in the sense of another permanent satellite. But a Moon occupying a very different orbit, appearing vastly larger in the sky and exerting a much stronger influence on our planet. And could that changing relationship have affected the develo...

For more than a century, scientists have tried to answer one deceptively simple question: Where did the Moon come from? The Moon is our closest natural companion, but its origin remains one of the great stories of planetary science. The leading explanation is the giant-impact hypothesis. According to this model, the young Earth was struck by a large planetary body roughly 4.5 billion years ago. Material thrown into orbit eventually gathered together and formed the Moon. It is a powerful explanation. But it is not the only conceivable way to imagine the Moon's origin. What if the Moon wasn't created primarily from Earth at all? What if it was something that already existed? What if, before Earth and the Moon reached their present configuration, another planetary body existed in the inner Solar System — and a catastrophic event destroyed most of it? Perhaps the Moon could be the surviving remnant. This is not the established explanation for the Moon. There is currently no compell...