purines

Imagine DNA as a message written in a 4-letter alphabet. Those 'letters' are called nucleobases, and there are five of them: A, T, G, C, and U. Scientists collected tiny rock samples from an asteroid called Ryugu — a rock floating in space about 300 million kilometers from Earth — using a robotic spacecraft. When they looked very carefully at those rocks in a laboratory, they found ALL five of those biological 'letters' inside. Nobody put them there; they formed naturally in space through chemistry involving ice, water, and simple ingredients like ammonia. It's like finding all the pieces of an alphabet scattered across the cosmos, ready to be assembled into the language of life.