Space rocks, also known as meteoroids, are small celestial bodies that travel through space. They can vary in size from tiny grains to larger boulders. When these rocks enter the Earth's atmosphere and produce a bright streak of light, they are called meteors. If they survive the journey and land on Earth, they are referred to as meteorites. These space rocks are made up of various materials, including metals and minerals, and can provide valuable information about the early solar system. Some famous space rocks include the Chelyabinsk meteor and the Hoba meteorite, which help scientists study the formation of planets and other celestial bodies.