Tonight – March 26, 2017 – look for the planets Mercury and Uranus rather low in the western sky, starting around 30 to 60 minutes after sunset. They’ll be in the same binocular field. Depending on where you live worldwide, Mercury and Uranus are closest on our sky’s dome on March 26 or 27. Their conjunction is March 27 at approximately 06:00 UTC; translate to your time zone.
The Northern Hemisphere has the advantage over the Southern Hemisphere for witnessing the coupling of these two planets at evening dusk. For instance, at mid-northern latitudes, these two worlds set about 90 minutes after the sun; yet, at comparable latitudes in the Southern Hemisphere, Mercury and Uranus set about 30 minutes after sunset.
Wherever you are, you’ll benefit from an unobstructed horizon in the direction of sunset. Moreover, if you can perch yourself on a balcony or hill, you can optimize your chances of catching Mercury and Uranus over the sunset point on the horizon.
Click here for recommended almanacs; they can help you find out when the sun, Mercury, and Uranus set in your sky.
Two worlds are said to be in conjunction when they are north and south of one another on the sky’s dome (that is, they’ll have the same right ascension). At this conjunction, Mercury passes somewhat more than 2o to the north of Uranus. Your finger at an arm length spans about 2o of sky.
After tonight, look for Mercury to climb upward and Uranus to sink downward.
There’s a consolation prize, should you miss Mercury and/ or Uranus at dusk. The red planet Mars is still visible after sunset and will stay out until after nightfall. This modesty-bright world should be yours to behold in a dark sky.
Then, after finding Mars, turn opposite the sunset direction, and look east. In your eastern sky, after as the sky is truly dark, you’ll find the brightest starlike object in tonight’s evening sky, the king planet Jupiter.
Bottom line: Mercury and Uranus are in the same binocular field on March 26 and 27, 2017. Their conjunction is March 27.