Sunday Science: The Moon

In the last 10 days, we were treated to a Super Blue Blood Moon AND the first flight of the SpaceX Falcon Heavy rocket. If Musk's dreams are realised, we may be shuttling humans to and from the Moon in a matter of years.

It's so exciting to see space travel peaking the world's interest again. And, for most interstellar journeys, it all starts with the Moon.

Where did the Moon come from?

Our Moon is quite unusual compared to other moons in the Solar System because it is the largest moon compared to the size of its host planet. Big Moons should orbit big planets. 

But that's assuming that our Moon formed in the same way many other moons did: when a planet is forming, some of the material is pulled together to form a moon. This is known as accretion.

But our Moon's composition is too dissimilar to the Earth for this to have happened. So, we believe the Moon was formed when a Mars-size body called Theia collided with the early Earth. Dramatic stuff.

The size of the Moon (Storm trooper mug) compared to the Earth (Lego head). However, if we wanted to represent the distance between the two bodies to scale, they'd need to be more than 100m apart.

What is the Moon made from?

Sadly, not cheese. It's predominantly made of rock and the dusty surface is covered with impact craters and dead volcanoes. These craters formed from asteroid collision millions of years ago but, because there's no weather, you can still see them today.

One of the goals of the Apollo 16 mission was to "pick up rocks", according to astronaut Charlie Duke. The Apollo 16 mission collected nearly 213 pounds of rock and soil samples and, despite extensive geological training, Charlie admitted they chose to "pick up one of every colour" on the lunar surface. 

Under the surface, the Moon is likely to have a small core of iron and a thick mantle of rocks rich in iron and magnesium.

Here's a final interesting fact about the Moon and its average 238,855 mile distance from the Earth. You could fit every planet in the Solar System between the Moon and Earth.

Image from http://www.slate.com

Does the Moon affect the Earth?

Yes. The Moon's gravity pulls the Earth and causes the tides in our oceans. The pull of the Moon is also slowing the Earth's rotation down, causing every day to increase by 2.3 milliseconds every century. And the Moon is also getting 1.5 inches further away from the Earth every year.

We also believe that the Moon's gravitational effect on the Earth caused it to tilt at just the right angle to produce  a relatively stable climate over billions of years. This effect, combined with the planet's tides, allowed life to flourish. 

So, if there was no Moon, there may be no life on Earth.

Extra reading and watching

If you want to find out more about exploration of the Moon, this post from National Geographic is a great starting point. And here are some great lunar stats.

SpaceX is not the only entity interested in going to the Moon. Five missions are planned in 2018, including: a Chinese mission to land a rover on the far side and the Chandrayaan-2, which has been developed by the Indian Space Research Organisation and will include a moon orbiter and a rover.

Two of the other lunar missions will be privately-funded. These are Hakuto, a group of space professionals inspired by Google’s Lunar X Prize, and Part-Time Scientists, a group of volunteer scientists and engineers based in Germany that plan to use SpaceX rockets and deploy two rovers. Finally, NASA’s TESS will also perform a flyby of the Moon.

The colonisation of the Moon is another fascinating prospect. And one that we're getting closer to realising. And if you're wondering why we should go to the Moon in the first place, this post from NASA is a rich pool of resources. 

​There's also great fun to be had on the Moon, if this video is anything to go by:

What is Sunday Science?

Hello. I’m the freelance writer who gets tech. I have two degrees in Physics and, during my studies, I became increasingly frustrated with the complicated language used to describe some outstanding scientific principles. Language should aid our understanding — in science, it often feels like a barrier.
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So, I want to simplify these science sayings and this blog series “Sunday Science” gives a quick, no-nonsense definition of the complex-sounding scientific terms you often hear, but may not completely understand. 

If there’s a scientific term or topic you’d like me to tackle in my next post, fire an email to [email protected] or leave a comment below. If you want to sign up for our weekly newsletter, click here.