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Moon near Castor and Pollux January 29

Tonight – January 29, 2018 – 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 morning hours on January 31 for us in North America, and, of course, this full moon is a Blue Moon, and a supermoon and will undergo a total eclipse – a super Blue Moon eclipse. Meanwhile, the January 29 moon is a waxing gibbous moon. It’s near the bright stars Castor and Pollux in the constellation Gemini the Twins.

Although we’ve drawn 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. These two stars are bright and noticeable for being near one another. They form the northeastern part of the Winter Circle.

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 above.

That brilliant star on the other side of the January 29 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.

On a dark night, star-hop to the constellation Gemini by way of the constellation Orion the Hunter.

Bottom line: On the night of January 29, 2018, 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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