Moon Steps On The Lion’s Paws Tonight

Watch for the gibbous moon to slide close to Regulus tonight. Five fists below and left of the moon, you’ll spy the bright duo of Jupiter and Spica (Virgo’s brightest star), while further east, Arcturus’ orange twinkle will catch your eye. Alphard, brightest star in Hydra the Water Snake, also has an orange hue. Created with Stellarium

The moon’s getting brighter and brighter as its phase fills out this week. I can tell because it’s easier to spot my black dog on our nightly walk. Instead of blending into the darkness, she’s an inky shape against the moonlit road. Moonlight’s a strange thing. We’ve lost most of our snow cover as the weather has warmed, exposing pale brown and gray grasses in the open fields. But under the illumination of last night’s swelling moon, the fields glowed bright enough as if still covered in snow. I actually looked twice to make sure.

Jupiter and Spica catch the eye as they rise up into the southeastern during early evening hours. Credit: Bob King

Tonight’s moon has a pleasant surprise in store. A waxing gibbous, it will pass just 1° — your pinkie extended at arm’s length — below Regulus, the brightest star in Leo the Lion. Regulus, a name meaning “little king”, lies just in back of the lion’s front paws.

We call these close alignments of celestial objects conjunctions. They’re pleasing to view with both the naked eye and binoculars. Far below the moon and just one day before opposition, you’ll spot unmistakable Jupiter, now the brightest planet in the evening sky.

Tomorrow, Jupiter reaches opposition, when it’s lined up directly behind the Earth and opposite the sun in the sky. It will rise around sunset, reach its highest point in the sky around 1 a.m. and set the next morning around sunrise. On the 8th, the planet will be closest to the Earth and brightest for all of 2017.

Jupiter watchers can use this photo guide to help identify some of the more obvious features visible on the windy, cloudy planet.  Credit: Damian Peach with labels by the author

The best views of any planet are when its close, so opposition traditionally marks the time when amateur astronomers make a point to view the planet every clear night we can. Even a small telescope will show its two most prominent “stripes” or cloud belts, called the North and South Equatorial Belts, and the planet’s four brightest moons: Io, Europa, Ganymede and Callisto.

For more observing tips on observing Jupiter, please see my article, Jupiter Close, Bright and Up All Night on Sky & Telescope’s website. Happy moonlight nights!

6 Responses

    1. astrobob

      Hi Carol,
      The difference is because Earth is moving toward its July aphelion — outward in the direction of Jupiter as it were, so even though they’re not exactly aligned on the 8th, they’re a smidge closer.

      1. astrobob

        Carol,
        I’d do one for you but can’t at the moment. Another tiny factor is that Jupiter is now moving closer to the sun after its Feb. aphelion. So … with Earth moving AWAY from the sun and Jupiter toward it, they still approach one another more closely until the Earth (faster planet) moves on and the separation increases.

          1. astrobob

            Glad to hear it! You always ask great questions that help to elucidate interesting details about a topic!

  1. caralex

    Dang! I still don’t get it! Is there a solar system diagram I could run to picture it visually?

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