Thread by @CosmicRami

Spending my Saturday night in doing research, and have just come across something I have been looking for, for some time now.

Kinda exciting to finally have it and read it in detail.

@drspacejunk knows I've been going on about this #RadioAstronomy topic for some time ...

🧵

so many of you have heard me go on and on about the Lunar far side, and preserving this as a site of importance heritage for a number of reasons, but in particular for the purpose of #RadioAstronomy ...

If not, here's a couple of quick tweets as a recap ...

Due to the axial rotation and orbit of the Moon, the same side normally faces the Earth. This is called the near side. Which means there is a far side as well, the face that we don't see because it always faces away from the Earth.

So, because of this, opportunity arises!

On Earth, we produce Radio Frequency transmissions for everything - our phones, TV, car radios, submarines, satellite communications, navigation, radar, observations, etc.

Earth leaks ALL of these transmissions into space and across the Solar System ...

Bu the Lunar far side, always facing away from Earth, lives in a sort of Radio Frequency (RF) shadow from Earth's transmissions ...

The RF spectrum is shared by so many users and services. Here's what the Australian allocation looks like!

📸 Wireless Institute of Aus.

There's lots of things, jammed into a limited number of bands available. A lot of these things make life more efficient/easier for many humans on Earth (e.g. Wi-Fi).

The bright yellow boxes are radio astronomy allocations - rather small!

These bands are coordinate and managed by the International Telecommunication Union (ITU), which is a special agency of the United Nations.

This ensures certain bands apply to certain things and there isn't any interference, cross-over or battles for these bands.

Since all those bands are occupied for human activities on Earth, they all can't be used for the purpose of science, and in particular radio astronomy (because they are occupied with lots of existing transmissions).

If only there was a place free of Earth's RF transmissions...

Enter stage right, the Lunar far side (AKA the 'Shielded Zone of the Moon' - SZM).

Here's a place where radio telescopes could scan all these wide-ranging frequencies for scientific purposes and not have to worry about Earth's transmissions ...

Why is this important? Well, it could be the great unknown that holds an answer to one of our scientific questions.

Maybe there is some random type of object that emits ONLY in the same band as your fav local radio station - and its hidden from our view because our transmissions

That's obviously a very^2 hypothetical example and there are a number of factors that I have not mentioned, but I was just trying to provide a quick analogy of the potential ...

Now of course to do this kinda research you would need to build radio telescopes on the lunar far side, which comes with its own set of HUGE challenges (funding, maintenance, delivery, data processing/transmission, etc.) ...

But the idea is starting to gain a little ground...

For example, NASA has started to consider the proposal. Again, these are very EARLY stage ideas and require LOTS more thinking, planning and consideration ...

nasa.gov/directorates/s…

So I guess if we ever wanted to do this science on the far side of the Moon, we would need to start considering the preservation of the Shielded Zone of the Moon - in particular from the oncoming/growing commercialisation of space and access to the Moon by LOTS of parties.

And sure, it might seem like early days to be thinking about this stuff, but there are already things happening on the lunar far side - e.g. China's relay Queqiao satellites!

nssdc.gsfc.nasa.gov/nmc/spacecraft…

📸 Nature

So I was doing some digging and reading about any protections that the Shielded Zone of the Moon has and happened to come across the International Telecommunication Union Recommendation RA.479-5 (current, and in force, since approved in May 2003)

itu.int/rec/R-REC-RA.4…

And I was pleased to note that the ITU recommends that as a first recommendation:

"all frequencies below 2 GHz in the SZM should be accessible to radio astronomy"

and additionally spectral lines that cannot be observed from Earth's atmosphere should also be retained ...

There is also a recommendation for communications on the Lunar far side from this document is to be between the 2 - 3 GHz band.

Though, tbh - I don't know how accepted/practiced this is/will be ...

Looks like there was a resolution passed at the 22nd IAU general assembly too.

Anyhoo, I'm kinda just scratching the surface here - and loving it! But am doing some documenting as well ... so if anyone out there in Twitter land knows someone who might know someone, I'd love to chat more with them - both on the science side AND legal framework.