Leap With A Gazelle / Aurora Alert!


(Created with Stellarium)

My clear sky antennae are twitching so I’m optimistic for tonight. Given that a clear leap night is a rarity, we’d certainly want to look at something fitting for the occasion. I would offer the "Three Leaps of the Gazelle." This curious pattern, consisting of three pairs of stars, is an ancient Arab asterism that nowadays comprise the feet of the Great Bear or Ursa Major. Use the map above to track the stellar gazelle across the night sky. Start with the familiar Big Dipper, which stands on it Handle in the northeastern sky during the early evening hours.

While you’re out, keep an eye peeled for the Northern Lights. They snuck up on us two nights ago, hovering like a frosty breath below the "W" of Cassiopeia. Alaskan skies lit up last night with one of the best auroras of the year, all brought on by a strong solar wind. The wind is a stream of subatomic particles expelled by the sun. When they ram into our planet’s magnetic field at 450 miles per second, they tweak it in a way that sends cascades of high speed electrons and protons into our upper atmosphere. These strike air molecules and excite them to glow. Green and sometimes red are from oxygen. Reds are excited nitrogen. I’ll be out watching and I hope you will too.

(Northern Lights — Bob King / News Tribune)