Murky Milky Way: Tilt of Earth leaves bulk of visible galaxy at level of our horizon in Clark County

Stargazers accustomed to scanning the Milky Way galaxy may notice something odd overhead this month: barely any milk in that way.

Don’t worry, the galaxy — comprising something like 100 billion stars — is all still there. It’s we earthbound viewers who’ve tilted upward, leaving the bulk of visible galaxy down at the level of our horizon.

The Milky Way is a vast oblong spiral, over 100,000 light-years from end to end (in miles that’s 600,000 trillion), but only about 1,000 light-years wide. Our solar system and our Earth are embedded in one arm of the Milky Way, about halfway between its center and its outer edge. Nearly everything we see overhead at night is part of the Milky Way.

As Earth revolves around the sun and the sun revolves around the galactic center, we are often tilted so the thickest bulk of the galaxy is visible overhead. On dark, clear nights, it can look like a glowing band of faint white, hence the name.

But on May evenings before midnight, the somewhat flat Milky Way is just level with our horizon, according to Jim Todd, the director of space science education at OMSI. That leaves not much milk for we denizens of the Northern Hemisphere — until after midnight, as the Milky Way starts rising in the east.

Before that, with the glow of the Milky Way out of the way, you’ve got great viewing conditions for deep sky objects like distant galaxies.