This gorgeous filtered image is a 6,000-year-old snapshot of a slowly dying star. When the star at the center of the Little Gem Nebula reached the end of its lifespan, it began ejecting its outer layers into space in glowing clouds of gas. Its stellar wind pushes the gas outward into this colourful bubble.
The Little Gem Nebula is just half a light year across — a tiny speck in cosmic terms — and it's 6,000 light years away, but it shines in gorgeous detail in this image from NASA's Hubble Space Telescope. If you have a telescope, look for this little nebula in the constellation Sagittarius.