Ursa Minor
Ursa Minor, wearing the guiding North Star (Polaris) at the tip of its tail. Shaped like a little ladle, it is the compass of the night sky.
Science
The sciencePolaris, at the tip of Ursa Minor's tail, is the current "North Star"; because Earth's axis points almost exactly at it, it stays nearly fixed all night, marking true north. For thousands of years it has been the guiding star for navigation and direction. But because Earth's axis wobbles in a precession with a cycle of about 26,000 years, the pole star changes with the ages — about 5,000 years ago, in the age of Egypt, it was Thuban in Draco; about 12,000 years from now it will be Vega in Lyra. Polaris itself is also a Cepheid variable, its brightness changing ever so slightly.
Mythology
How it became a constellationIt is said to depict Arcas, son of the nymph Callisto who became Ursa Major. At the moment he raised his bow without recognizing his mother, Zeus lifted them both into the sky and set them side by side as Ursa Major and Ursa Minor. Both bears have unusually long tails, said to have been stretched when Zeus flung them skyward by pulling on their tails. To sailors, the star at the tip of this little bear's tail was the guide to whom they entrusted their lives.
Observing Guide
how to observe🔭 How to find it
Take the two front stars of the Big Dipper's bowl — Merak and Dubhe (the outer edge where water would pour out) — and extend that line upward by about five times their separation, and you'll land on Polaris, the North Star. Polaris is the tip of the Little Bear's tail, and from there you can trace the fainter stars into the shape of a Little Dipper. The two front stars of that bowl, Kochab and Pherkad, are bright enough to be called the "Guardians of the Pole" and make excellent signposts.
✨ What to look for
Ursa Minor is made up of faint stars and has virtually no bright nebulae, clusters, or galaxies, so there's little to recommend for deep-sky viewing. The most interesting target is the constellation's lead star, Polaris itself: in a small telescope it reveals a faint companion (a double star), and it's also a Cepheid variable whose brightness shifts ever so slightly. There is a faint spiral galaxy, NGC 6217 (about magnitude 11), but it requires a large aperture.
📍 Where to see it (US · Canada · UK · Australia)
Ursa Minor sits right at the north celestial pole, so from the US, Canada, and the UK it is circumpolar — it never sets and wheels around Polaris every night of the year. Polaris itself stays fixed at an altitude equal to your latitude (about 40° from the US, and over 50° from Canada and the UK), with the other stars turning around it all night long. From Australia, however, the Little Bear lies below the northern horizon and never rises at all.