Hubble time! 🌌 The swirling, paint-like clouds in the darkness of space in this stunning image seem surreal, like a portal to another world opening up before us. But in fact, we are seeing vast clouds of ionised atoms and molecules, thrown into space by a dying star. This is a planetary nebula named Kohoutek 4-55, a member of the Milky Way galaxy situated just 4600 light-years away in the constellation Cygnus (the Swan). Planetary nebulae are the spectacular final display at the end of a giant star’s life. Once a red giant star has exhausted its available fuel and shed its last layers of gas, its compact core will contract further, enabling a final burst of nuclear fusion. The exposed core reaches extremely hot temperatures, radiating very energetic ultraviolet light that energises the enormous clouds of cast-off gas. Molecules in the gas are ionised and glow brightly; here, red and orange indicate nitrogen molecules, green is hydrogen and blue shows oxygen in the nebula. Kohoutek 4...