Science with Sam: What would happen if there was no moon?

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From moonstruck lunatics to the idea that it’s made of cheese, the moon has inspired more myth than fact. So much so that eventually Earthlings sent human explorers 384,402 kilometres away to find out if there really was a man in the moon. Sadly, they found no evidence of Lunarians or cheese. But they did find rock. And lots of it.

Today, the moon may seem a bit of a dull, uneventful place, raising the question, does it really need to be there? If, like Sam, you harbor a sinister wish to smash the moon to pieces, then this is the film for you. But be warned, you may come away with a whole new outlook. Watch on, it’s time to put the moon in its place.

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Video transcript

From moonstruck lunatics to the idea that it’s made of cheese, the moon has inspired more myth than fact. So much so that Earthlings eventually sent explorers 384,402 kilometres away to find out if there really was a man in the moon.

Sadly, they found no evidence of Lunarians or cheese.  All they found was a big lump of boring rock.

As we stare at the moon and contemplate the comforting rhythm of its monthly phases, you may ask yourself, what does the moon actually do?  Does it really need to be there? And, what would happen if we were to smash it to pieces?

Moon formation

Our planet didn’t always have a moon.  The prevailing theory of the moon’s formation suggests that around 4.5 billion years ago, a Mars-sized boulder called Theia slammed into Earth, vaporising much, if not all of it, flinging out chunks of rock that eventually coalesced into the Moon.

Destroying the Moon could just be seen as revenge for the chaos Theia wrought on our world all those years ago.

Get rid of the moon

But there’s actually a really good reason to get rid of it. 

Observations of distant objects are often impossible because the moon outshines them by so much: it is 14,000 times brighter than Venus, which is the next-brightest object in the night sky. Without a moon, we’d be able to see much dimmer and more distant objects in space all year round, without having to wait for the right phase.

Another bonus is, if we did destroy the moon, it could potentially result in Earth having rings. Some astronomers even think that Saturn got its rings from a relatively small moon that got smashed up, or maybe a larger moon that had its outer layers stripped away as it fell into the young planet.

If our entire moon got turned into rings, they would be far larger and more impressive than Saturn’s. Although some huge chunks might fall to Earth and kill everyone.

So before we get all vengeful, it’s worth noting a few benefits our shiny sidekick brings.

A boon for life

As Earth spins, it wobbles slightly on its axis. On some worlds orbiting other stars, this causes extreme seasonal changes. The gravitational pull of the moon moderates Earth’s wobble, keeping the climate stable. That’s a boon for life.

Without it, we could have enormous climate mood swings over billions of years, with different areas getting extraordinarily hot and then plunging into long ice ages.

We might even have the Moon itself to thank for life on Earth. As the moon orbits, its gravity tugs on the side of Earth closest to it more than the side that’s farther away, sloshing the seas back and forth. We call this sloshing the tides. 

Today, tides are good for surfers and sea creatures, but in the past they might just have provided the spark needed to turn the primordial soup – a collection of simple, precursor chemicals – into complex life.

Four billion years ago, about the time life began, the moon was probably about half as far from Earth as it is now, huge tides would ebb and flow every few hours.

According to Richard Lathe’s tide theory of life, these tides created the conditions under which double stranded DNA molecules replicated with each tidal cycle. 

This may have created the molecular foundations for the first lifeforms to emerge. This theory is fairly speculative, however, and only one of a number suggested for the origin of life.

Even if tides aren’t responsible for the emergence of life, they certainly make life on Earth far more diverse. Along the coast, distinctive habitats have necessitated unique adaptations. It’s here you’ll find intertidal spiders, like this one named after Bob Marley or sea stars that like nothing more than prying open a mussel, ejecting their own stomach into the hapless mollusc and feasting on the digested mess later.  Yum. They might be bizarre, but these creatures really do appreciate our Moon.

In the late Silurian and early Devonian periods, some parts of the world saw tides 4 meters high. When the tide receded, some fish would have been isolated in small pools, and it’s thought that this intertidal environment might have spurred the evolution of lungs and legs for walking on land.

400 million years or so later, some descendants of those first fish to foray onto land evolved brains large enough to ask whether the moon served any real function.

Earth’s geological mirror

Apollo 11 and five subsequent lunar lander missions saw 12 people explore the moon’s surface to uncover more of its secrets.

Apart from being a phenomenal technical achievement and a massive propaganda win, those missions greatly advanced scientific knowledge.  Getting rid of the Moon, it would seem, would mean getting rid of the best place we have to learn about Earth’s own past.

Today, the moon may seem a bit of a dull, uneventful place, but it wasn’t always like that. When it was formed 4.51 billion years ago — just 60 million years after the solar system itself took shape, the moon was volcanically active, boasted a crust, mantle and core just like Earth, and was just as susceptible to a meteorite strike or 10,000.  Whatever was happening on the moon was also going on on Earth.

Since then, Earth’s tectonics and erosion have erased much of its geological history, smoothing out billions of years of violent activity. That means the moon is the best historical record we have.

The Apollo missions returned samples with tantalising hints of water.  And in 2008, India’s Chandrayaan-1 mission detected evidence for chemical bonds between hydrogen and oxygen. More probes followed and in October 2020 NASA announced it had found water on the sunlit surface of the moon, showing that it wasn’t just found in cold, shadowed places.  This lunar water could be key to an exciting future for the moon.

Return to the moon

NASA is already planning to return humans to the moon in 2024, including the first female astronaut to set foot there. Billionaires Jeff Bezos and Elon Musk both plan to visit with their respective spacecraft, Blue Moon and Starship.  Meanwhile, China and Russia are cooperating on plans to build a lunar research outpost. 

Aside from new scientific discoveries, onward travel from the moon is a distinct possibility. The energy required to send objects from the Moon to space is far lower than from Earth to space. If we are ever going to send humans to Mars or beyond, the Moon seems like a good place to start. 

So there are pluses and minuses to the idea of smashing up the moon. What do you think? Keep it for the tides, our mild seasons and a site for space bases?

Or blow it up as a boon for astronomy, revenge for Theia and to decorate Earth with rings.

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