银河与极光花
2022年10月18日 Milky Way Auroral Flower Image Credit & Copyright: Göran Strand Explanation: Could the stem of our Milky Way bloom into an auroral flower? No, not really, even though it may appear that way in today’s featured all-sky image. On the left, the central plane of our home galaxy extends from the horizon past the middle of the sky. On the right, an auroral oval also extends from the sky’s center — but is dominated by bright green-glowing oxygen. The two are not physically connected, because the aurora is relatively nearby, with the higher red parts occurring in Earth’s atmosphere only about 1000 kilometers high. In contrast, an average distance to the stars and nebulas we see in the Milky Way more like 1000 light-years…