The Antiatoms Recipe
Scientists at CERN can build "antiatoms". So far they've managed to make just a few. But to really study the antiatoms, you need a lot of them! So the plan is to make more.
How do you build an antiatom? Well, you choose an atom, the simpler the better, and you look how many electrons, protons and neutrons your atom is made of. Then you take the corresponding amount of positrons, antiprotons and antineutrons, and build a copy of your original atom. And then you have an antiatom!
Now the question is: will it behave like a mirror image of the original one?
At CERN, they chose to mirror the atom of hydrogen (start with the simplest one!) Hydrogen is made of just one proton and one electron stuck together. So to build antihydrogen, you need to trap an antiproton and get a positron to stick to it!
One of the tricky steps in this recipe is to "slow down" the antiproton; in order to do this, CERN is building a special machine, called the Antiproton Decelerator (AD).