Astronomy Picture of the Day

Explanation: Yes, but can your aurora do this? First, yes, aurorae can look like rainbows even though they are completely different phenomena. Aurorae are caused by Sun-created particles being channeled into Earth's atmosphere by Earth's magnetic field, and create colours by exciting atoms at different heights. Conversely, rainbows are created by sunlight backscattering off falling raindrops, and different colours are refracted by slightly different angles. Unfortunately, aurorae can’t create waterfalls, but if you plan well and are lucky enough, you can photograph them together. The featured picture is composed of several images taken on the same night last month near the Skógafoss waterfall in Iceland. The planning centred on capturing the central band of our Milky Way galaxy over the picturesque cascade. By luck, a spectacular aurora soon appeared just below the curving arch of the Milky Way. Far in the background, the Pleiades star cluster and the Andromeda galaxy can be found.