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Moon near Castor and Pollux January 22

Use the bowl of the Big Dipper to find Castor and Pollux.

Tonight – January 22, 2016 – the moon might look full to you, but it’s not, yet. Full moon comes when the moon is most opposite the sun. That’ll be during the evening hours on January 23, 2016, for us in North America (January 24 for Europe, Africa and Asia). Meanwhile, the January 22 moon is a waxing gibbous moon. It’s near the bright stars Castor and Pollux in the constellation Gemini the Twins.

You can also use the Big Dipper to locate Castor and Pollux. Draw an imaginary line diagonally through the bowl of the Big Dipper, as shown on the sky chart on the right.

When the moon turns full on the night of January 23-24, it’ll still be in the vicinity of the Gemini stars, Castor and Pollux.

Although we draw in the stick figure of the Gemini Twins on the chart at the top of this post, you might not see much of Gemini in the moonlight glare except for Castor and Pollux.

The rest of the constellation Gemini the Twins appears as two streams of stars extending from Castor and Pollux. These stars are faint. Near the month’s end – after the moon drops out of the evening sky – go to a rural location to look for the Twins to shine in all their starlit majesty.

By the way, that brilliant star on the other side of the January 22 moon is Procyon, sometimes called the Little Dog Star.

You might not know that Procyon – and Castor and Pollux – offer an alternate way of finding Polaris, the North Star. You can draw an imaginary line from Procyon and then in between the two Gemini stars, and then take a long jump northward to locate Polaris, the North Star.

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Most people use the two outer stars in the bowl of the Dipper - Dubhe and Merak - to find Polaris, the North Star. A line between these two stars always points to the North Star.

Most people use the two outer stars in the bowl of the Dipper – Dubhe and Merak – to find Polaris, the North Star. A line between these two stars always points to the North Star.

And speaking of star-hopping … if you’re familiar with the winter constellation Orion, draw an imaginary line from the star Rigel through the star Betelgeuse to locate Castor and Pollux.

These bright Gemini stars outline the northeastern part of the Winter Circle.

Beginning around January 20 - through mid-February - you can see five bright planets at once in the predawn sky.

In late January – through mid-February – you can see five bright planets at once in the predawn sky. We haven’t been able to see five planets simultaneously since 2005. Read more.

Bottom line: On the night of January 22, 2016, let the full-looking waxing gibbous moon guide your eye to the bright Gemini stars, Castor and Pollux!

Gemini? Here’s your constellation

EarthSky astronomy kits are perfect for beginners. Order today from the EarthSky store

Bruce McClure

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