Tonight, the waxing gibbous moon swings close to a sparkling blue-white Royal Star and the red planet Mars. That Royal Star is Regulus, the brightest in the constellation Leo, the star depicting the Lion’s Heart.

There are several telltale ways of knowing which light is Mars and which is Regulus.

First of all, Mars is the brighter of the two. Secondly, Mars glows red while Regulus radiates blue-white. If you can’t make out the contrast of color in tonight’s lunar glare, try using binoculars. And for tonight, Regulus is the closer of the two to the moon.

Regulus wins acclaim as the most important of the four Royal Stars of ancient Persia. These Royal Stars mark the four quadrants of the heavens. They are Regulus, Antares, Fomalhaut, and Aldebaran.

The constellation Leo the Lion from Urania. Credit: Wikipedia

Regulus: Heart of the Lion

Four to five thousand years ago, the Royal Stars defined the approximate positions of equinoxes and solstices in the sky. Regulus reigned as the summer solstice star, Antares as the autumn equinox star, Fomalhaut as the winter solstice star, and Aldebaran as the spring equinox star. Regulus is often portrayed as the most significant Royal Star, possibly because it symbolized the height and glory of the summer solstice sun. Although the Royal Stars as seasonal signposts change over the long coarse of time, they still mark the four quadrants of the heavens.

Regulus coincided with the summer solstice point some 4,300 years ago. In our time, the sun has its annual conjunction with Regulus on or near August 22, or about two months after the summer solstice – or alternatively, one month before the autumn equinox. Regulus will mark the autumn equinox point some 2,100 years into the future.

Regulus and Mars follow the moon westward across the sky tonight. They appear in the southeast at nightfall, highest in the sky around mid-evening, and low in the west during the wee hours before dawn. Watch for the glorious threesome – the waxing gibbous moon, the Royal Star Regulus and the red planet Mars – to pop out in the southeast as soon as darkness falls.

Article source: http://earthsky.org/tonight/moon-swings-close-to-a-royal-star-and-mars-on-april-2

Tags: waxing gibbous moon, Royal Stars, autumn equinox, the red planet Mars, Royal Star, Royal Star Regulus <BR/>

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