A crescent Moon joins Saturn, Mars, and Regulus

The sky this month


A crescent Moon joins Saturn, Mars, and Regulus

Astronomy: Roen Kelly

Binoculars will reveal a beautiful color contrast between orange Mars and bluish-white Regulus. Set against twilight's deepening azure sky, this is one of the summer's finest binocular sights. On July 4, enjoy the "red, white, and blue" of Mars, Regulus, and the early evening sky as America celebrates Independence Day.

Each night, Mars pulls farther from Regulus and draws closer to Saturn. On July 5, when the three objects span a straight line 5° long, they're joined by the 3-day-old crescent Moon 5° below Regulus. The next night, the Moon glows nearly 7° to the left of Mars.

Watch over the following 4 nights as Mars edges toward its July 10 conjunction with Saturn. Then, only about 0.7° separates the two worlds and both will be visible in a telescope's low-power field of view. Here's an opportunity to study a new color contrast, but a more subtle one. Compare Mars' orange hue to Saturn's wan, yellowish tint. Can you spot the difference?

Saturn, shining at magnitude 0.8, is nearly a full magnitude brighter than Mars. This is the ringed planet's last month of visibility before it slips into the solar glare. The Sun will hide Saturn for about 2 months before the planet reappears in the morning sky. Saturn remains so low that telescopic viewing won't reveal much in the early evening's unstable air. But take a quick glimpse at the planet's narrowing rings. They'll be even more edge-on when Saturn reappears in the fall.


Hoping for a clear sky! Happy 4th! :)