Uranus Reaches Opposition on Halloween in 2020

Christine Schmitt, Flickr // CC BY-NC-ND 2.0
Christine Schmitt, Flickr // CC BY-NC-ND 2.0 / Christine Schmitt, Flickr // CC BY-NC-ND 2.0
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Uranus is roughly 1.75 billion miles away from Earth, which makes it difficult to spot without a telescope most nights. But on Saturday, October 31, the seventh planet from the sun will be worth looking for. Uranus reaches opposition that night, making it appear extra bright in the night sky.

What Is Uranus at Opposition?

An opposition occurs when the Earth falls perfectly between another planet and the sun. When this happens, the sun's light appears to fully illuminate the planet's surface, boosting its brightness level to the maximum.

Uranus reaches opposition on October 31 in 2020. During this event, Uranus will hit a limiting magnitude of 5.86, which is about the minimum brightness for what's visible with the naked eye.

How to Look for Uranus at Opposition

Spotting Uranus at opposition will be slightly more difficult in 2020 than in years past. The phenomenon coincides with a full moon that will make dimmer stars and planets—including Uranus—harder to see in the night sky. The planet sits in the constellation Aries, which regrettably appears close to the moon for most of the night.

Uranus should appear as a small, blue-green disc when using a telescope. Even if you have trouble spotting the seventh planet, it will still be worth checking out the night sky on October 31: Halloween this year coincides with a rare blue moon.