Spot Uranus at Opposition – Sky & Telescope

The solar system’s seventh planet arrives at opposition on November 21st, not far from the Pleiades star cluster in Taurus. Discovered telescopically by William Herschel in 1781, Uranus is the third-largest planet in our solar system (four times the diameter of Earth). But its orbit is so far away, some 1.8 billion miles (2.9 billion km) from the Sun, that it looks relatively dim in the nighttime sky.

Fortunately, Uranus is its closest to Earth all year right now, and you can find it easily in the evening sky using the chart below. Shining at magnitude 5.6 with a disk 3.8″ across, Uranus might be faintly visible without optical aid under dark, moonless skies — for those of your with excellent eyesight. But most of us will need to grab a pair of good binoculars or a small telescope and pick a viewing location without bright lights nearby.

First, find the small but pretty Pleiades star cluster (Messier 45) by eye. The Pleiades are well up in the eastern sky by around 7 p.m., but they’ll gradually move to almost overhead by 11 p.m. Then look to the lower right of the Pleiades by 4½° — about the width of your middle three fingertips together when you hold out your arm.

That’s where to point the binoculars. You’ll see an unevenly spaced row of three similarly bright stars that includes 14 and 13 Tauri, and the one on the left end is Uranus. Over the next week, Uranus inches westward in retrograde motion, and as December begins it lines up more closely with those two stars.

Even a small telescope will reveal the planet’s tiny disk. Its brightest moons (Titania and Oberon) are visible in 8-inch and larger instruments used at high magnification — and that’s what you’ll need to discern the planet’s pale-blue countenance. To find out when and where to look for these moons, visit our “Moons of Uranus” interactive observing aid.

If your sky is cloudy tonight, or if you can’t get to a dark location, don’t worry: Uranus will be in this same general location for several weeks, and the evening sky will be free of bright moonlight until about Thanksgiving.