So you want to talk to aliens eh? What do you see when you look up in the night sky? Planes? Planets? Stars? The moon? Maybe a galaxy or two? But… where are all the aliens?
The reality is, everything that we see is caused by photons registering in our retinas and the only things humans can see is visible light.
That sucks. Because visible light only makes up about 0.0035% of everything visible in the universe!
We are completely blind to 99.997% of the universe.
Now that’s a problem. We simply aren’t on the same wavelength as these aliens! 😉
So, astronomers realized how blind humans were and thus we created a plethora of high precision instruments to account for everything else our stubby eyes can’t see. We called it radio astronomy.
How It Works.
Light is a form of electromagnetic wave. This means that there is a spectrum of different types of ‘light’. For example, microwave (the same microwave to heat your food) is, in essence, the same thing as the visible light except its traveling in much longer wavelengths.
Human eyes are built to only detect a small range of these wavelengths, specifically between 380–700 nanometers. That's cool, but the entire universe operates at a range of 1 km — 1 trillionth of a meter. Once again human eyes suck.
Radio waves operate at a few meters to a few centimeters in range. This is perfect for both communication and observation because radio waves can pass through gas particles.
This is vital since in space there is a ton of debris (such as clouds of dust and hydrogen) and thankfully radio waves pass straight through that!
So all we need to do is to build a detector. No problem! We’ve been perfecting the art of radio’s for decades and isn’t new technology.
Radios work by having an antenna that can receive the signal and transfer the information into analog (variation of electrical pulses). We then translate it into digital information and bam! Our first readings from our new intergalactic friends. Simple.
Let's Build This At Home.🔭
Well in order to pull this trick off you’d need a few things (you can find everything from your local hardware store or Amazon)
- Satellite dish (for satellite tv) (Note: should come with an LNB)
- Sat finder
- 22 gauge wires
- Coaxial cable
- 1.7–2.1 mm DC Power supply (15 V, 1.5–2 A) + DC Socket 1.7mm — 2.1 mm
- Breadboard + jumper cables
- Soldering set
- Raspberry Pi or Arduino (I’m using a rasp pi) => fully set up with Desbian or Ubuntu
- Adafruit ADS1115 chip => used to convert analog to digital
- A uF 100 choke (just buy a ferrite core and wire it yourself)
- Time (you need quite a lot of it)
First, solder the socket to the 22 gauge wires. Then take the wire and loop it around a ferrite core (this is used to filter out noise) and strip the wires for further connection. It should look like this! (ignore my terrible soldering skills, first time doing it!)
Then you would take the newly stripped ends and solder it to the sat finder as so. (Note: you may have to break open the back case)
Next take unsolder the analog portion indicated below. This is where we will measure the voltage change in our sat finder!
We then wire the raspberry pi GPIO pins to the breadboard like so. For reference here are what each pin means and here are the schematics.
We run the wire to our ADS1115 chip to read the change in voltage. And connect to two parts!
Finally, we hook up the coaxial cable to the Satellite dish.
Okay, cool the hardware portion is done. Now let’s jump into a python script and see what we need to program.
So we need to do is install the packages for our chip. Download it from their website here.
Then we can just copy an example script that they have given us! Nothing super hard! We have choices to write or display our numbers and copying the script we are officially done building the telescope. Copy code from my GitHub here.
Okay cool, to test it out we just turn on the power supply and turn on our raspberry pi! And we can see the numbers being generated.
Note: the radio telescope works best if you are in a radio quiet area. Meaning away from wifi signals, radio towers, etc. This will interfere with the data you collected.
Here’s the finished product!
So did we see any aliens? Unfortunately no. Our homemade radio telescope isn’t strong enough, in comparison, the VLB (used for the black hole observation) was over 100x larger plus they had over 20 of them.
Despite our attempts, this is an amazing step forward into the huge potential of radio technology (despite how ancient this technology is).
If you are interested, stick around for more astronomy projects here to come.