Castor and Pollux sink to the horizon in spring

Castor and Pollux: Two dots side by side with arrow pointing down toward horizon.
Castor and Pollux in Gemini are twin stars that sink toward the horizon in the evening as summer approaches in the Northern Hemisphere. Chart via John Jardine Goss.

You can find Pollux and Castor, the twin stars of Gemini, in the west-northwest sinking lower each night from mid-May through mid-June. You might even be able to catch them for a few nights after that. This is the same Pollux and Castor that rose in the east-northeast in the early evenings around New Year’s Day. At that time of year, they pointed straight up from the horizon. It’s also the same two stars that shone nearly overhead in the cold nights of February and March.

Now, in the much warmer evenings of late spring, Gemini stands on the west-northwestern horizon, with Pollux and Castor forming a horizontal line in the twilight. The twin stars twinkle atop the constellation, while the sun, still in eastern Taurus, approaches the foot of Gemini and lies below the horizon.

Constellation Gemini with half above and half below the horizon.
In early to mid-June evenings, Pollux and Castor sit atop Gemini. The sun, which is below the horizon, sits near the foot of Gemini. On the solstice, June 21, the sun lies next to the lower rightmost star of Gemini. Chart via John Goss.
Two dots with two crescent moons below.
In early June, watch the crescent moon climb toward Pollux and Castor after sunset. By June 3, the moon will be above the brightest stars of Gemini.

Castor and Pollux photo gallery

Crescent moon on left with dots for Castor and Pollux at right.
View at EarthSky Community Photos. | Raúl Cortes in Monterrey, Mexico, took this image of Castor and Pollux with a fat crescent moon on May 16, 2021. Thank you, Raúl!
Pink twilight sky with Mars and Mercury marked, and also the stars Castor and Pollux marked.
View at EarthSky Community Photos. | Dr Ski in Valencia, Philippines, caught Pollux and Castor after sunset on June 19, 2019. On this date, Mars and Mercury had just passed conjunction. Thanks, Dr Ski!

Bottom line: Castor and Pollux, the brightest stars in Gemini the Twins, sink toward the horizon on spring evenings, disappearing from summer’s night sky.

May 13, 2022

Like what you read?
Subscribe and receive daily news delivered to your inbox.

Your email address will only be used for EarthSky content. Privacy Policy
Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.

More from 

John Jardine Goss

View All