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Mercury/Saturn conjunction coming soon!

Before daybreak tomorrow – January 12, 2018 – try catching the close pairing of the planets Mercury and Saturn as the predawn darkness gives way to morning dawn. The lit side of the waning crescent moon points in the direction of Mercury and Saturn, with these two planets sitting quite close to the sunrise point on the horizon. Seek for these two worlds low in the southeast around 90 to 60 minutes before sunrise.

The rising times for Mercury and Saturn vary somewhat around the world, depending on where you reside on the globe. At temperate latitudes in the Northern Hemisphere, these planets come up about one and one-quarter hours before the sun. At temperate latitudes in the Southern hemisphere, these embracing worlds rise about one and one-half hours before sunrise. Click here for a sky almanac that’ll give you the rising times for Mercury and Saturn in your sky.

No matter where you live, however, it will be to your advantage to find an unobstructed horizon in the direction of sunrise. It might also be helpful to have binoculars handy, because the viewing is sometimes murky near the horizon. Mercury will be the brighter of these worlds.

Although Mercury and Saturn will appear close to one another on the sky’s dome for the next several mornings, the actual conjunction date is January 13, with Mercury passing some 0.7o south of Saturn at that juncture. For reference, the moon’s diameter spans about one-half degree (0.5o) of sky.

Incidentally, there are two other bright planets that light up the January morning sky right now. You’ll see the planets Jupiter and Mars above the moon, and the planets Mercury and Saturn below the moon. For more on Jupiter and Mars, see yesterday’s Tonight Sky.

After their January 13 conjunction, Mercury will fall toward the sunrise day by day, whereas Saturn will climb upward from the glare of daybreak. Mercury will transition out of the morning sky and into the evening sky as this inferior planet reaches superior conjunction on February 17, 2018. Saturn will adorn the morning sky for many months to come.

See if you can find the red planet Mars a short hop below the king planet Jupiter, the brightest starlike object in the morning sky. Keep your eye on Saturn and Mars, and you’ll see Saturn and Mars edging closer and closer to one another over the next several months. In fact, Saturn and Mars will have their conjunction in early April 2018, with Mars swinging 1.3o south of Saturn on April 2, 2018.

Before daybreak for the next several days – January 12, 13 and 14, 2018 – get an eyeful of Jupiter and Mars above the moon, and Mercury and Saturn at or near conjunction below the moon.

Bruce McClure

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