This is a giant space cloud made of dust and gases such as hydrogen and helium. A nebula can form when a star dies in a massive explosion called a supernova. Other nebulae are star nurseries — places where stars are born. Over time, gravity pulls gases and dust together. When the clumps of matter get big enough, they collapse into big hot mass — a baby star.
In a sentence
The swirling clouds of dust inside nebulae can form sugars needed for life, including ribose, which is used in cell machinery.