A whorl of stars against the blackness, a disc-like nebula turns in the heavens. In each of us is the slightest trace of star dust. The blue green planet, Earth is awash with water, atmosphere and life. Echinoderma and trilobites are featured fossils in the early Palaeozoic exhibits. The Earth is some 4.6 billion years old.
Observations show that all heavenly bodies are receding from one another at a great rate of speed.
This has led astronomers to suggest that the known universe originated with an immense explosion, known as the Big Bang . Since that event some 15 billion years ago, the universe has been constantly expanding. Clouds of interstellar dust and gas, tattered, blown and compressed by galactic explosions, occasionally coalesced into dense masses held together by gravity. These masses became stars. The same processes are at work today, forming new stars in the vast heavens.