Story of antimatter

L-R: Antimatter is a form of matter (atoms and stuff) in which each particle (for example an electron) has the opposite set of quantum properties (such as electric charge) to its counterpart. In this composite image of the Crab Nebula, matter and antimatter are propelled nearly to the speed of light by the Crab pulsar

One of the mystifying aspects of the Universe is Antimatter. It is understood that matter is made of electrons, protons and neutrons whereas antimatter is identical to matter, except that it is composed of antielectrons, antiprotons and antineutrons.
When antimatter comes into contact with normal matter, they collide to produce an explosion emitting pure radiation. And this results in a complete annihilation of matter into energy. Every particle in the Universe has the common characteristics of mass and charge. However, with antimatter, the mass of the particle remains constant, while its electric charge is opposite. A normal matter such as a hydrogen atom contains 1 electron and 1 proton. The anti-particle, the anti-hydrogen atom, will have 1 positron (the antiparticle of an electron, which has the same mass as an electron but opposite electric charge) and 1 antiproton. This is why, after collision, the entire mass of both particles transforms into pure energy, a phenomenon that scientists believe, may usher an era of travelling at the speed of light. Similarly, the antiparticle of proton is antiproton which has the same mass as a proton, but with opposite charge, while the antiparticle of the neutron is an antineutron.
The modern quest of antimatter began back in 1928 by physicist Paul Dirac. It is now well known hat, for every atomic and subatomic particle, there is an antiparticle. How did antimatter come into being? Just like everything else, right after the Big Bang. Scientists believe that, immediately after creation of the universe, there were almost the same amount of antimatter as there was matter. But the cosmic process compelled them to annihilate each other out and eventually ushering today's matter-dominated Universe. At CERN's Large Hadron Collider, many believe that there are antiparticles still out there in the Universe. Scientists think that antimatters are created whenever high-energy particle collisions take place in the universe. Studies have found that when cosmic rays impact Earth's atmosphere, small quantities of antiparticles are produced in particle jets and these antiparticles are destroyed as soon as they come in contact with nearby matter. It is also believed that antimatter may still exist in large amounts in distant galaxies because of the inflation associated with the early expansion of the universe.