Messier 81
Model: gpt-4.1
Prompt version: 1.0
One of the brightest galaxies in planet Earth’s sky is similar in size to our Milky Way: big, beautiful Messier 81. Also known as NGC 3031 or Bode’s galaxy for its 18th century discoverer, this grand spiral can be found toward the northern constellation of Ursa Major, the Great Bear.
The sharp, detailed astrophotography view reveals Messier 81’s bright yellow nucleus, blue spiral arms, pinkish starforming regions, and sweeping cosmic dust lanes. But some dust lanes actually cut across the galactic disk (left of center), contrary to other prominent spiral features.
The errant dust lanes may be the lingering result of a close encounter between Messier 81 and the nearby galaxy M82 lurking outside of this frame. Scrutiny of variable stars in Messier 81 has yielded a well-determined distance for an external galaxy — 11.8 million light-years.