Tonight’s Scrap-of-a-Moon Challenge

Thin enough to slice bread! Chris Schur of Payson, Arizona photographed and observed this sliver of a moon on May 26, 2017 when it was just 19.2 hours old. Only 1% of the moon was illuminated at the time. Tonight’s moon will be a hair thicker. Chris Schur

Tonight’s moon will barely be there, but that’s exactly what will make it so beautiful. New moon occurred yesterday at 8:17 p.m. (Central Time), making this evening’s moon just 20 hours old from the East Coast, 21 hours from the Midwest, 22 from the mountain states and 23 from the West Coast.

Very young and very “old” moons (dawn crescents) are tricky to see because they’re so near the sun. Much too close to attempt to see in the daytime. We can only spot the new evening crescent 15 to 30 minutes after sunset very low in the western sky. Naturally, you’ll need an open horizon in that direction and a clear, haze-free sky. The further west you live, the slightly older the moon will be and the higher it will stand. East Coast observers have it toughest, but West Coasters should see it with relative ease.

The crescent is so thin tonight that my program simulation shows full outline of the earth-lit moon much better than the crescent. The sunlit crescent outlines the bottom, horizon-facing edge of the moon. Stellarium

I always bring a bigger set of eyes — binoculars — when attempting these challenging lunar slivers. The moon will float a short distance to the left (south) of the brightest area of sunset-afterglow on the horizon. Start there and slowly sweep back and forth looking for a white talon in the orange blush. Then move up one field of view and sweep that strip of sky. Make sure your binoculars are focused at infinity (a great distance) before searching.

If you find it, let the view melt into your eyes the way chocolate melts on the tongue. Next, carefully lower the binoculars while looking straight ahead to where you were pointing. Can you see the crescent with nothing but your eyeballs?

Now for the dirty details. The moon will only stand 2-3° high (the width of your index finger held at arm’s length against the horizon) 15-20 minutes after sunset. You can start looking a little earlier to get a head start but don’t bother until the sun sets, both because the moon will be lost in the daylight glare and you don’t want to accidentally look at the sun.

Everyone gets a little window of viewing. For folks in the upper Midwest where I live, there’s only 50 minutes between sunset and moonset tonight. To figure out your own personal viewing window, click here to get local sunset times and here for moonsets.

If you don’t find the moon tonight, it will be in the same direction tomorrow night but much easier to see and still thin as eggshells. Good luck!