Above photo: Crescent Uranus as seen by Voyager 2 in 1986, just after the craft’s flyby. From Earth, even through the most powerful telescopes, Uranus never appears as a crescent but is always seen at or near full phase. Image via NASA/JPL
The planet Uranus, seventh planet outward from the sun, comes closest to Earth for 2019 on October 27 at 21:00 UTC. Hours later, on opposition on October 28 at 08:00 UTC, Uranus will reach its yearly opposition, when it is most directly opposite the sun as viewed from Earth. In other words, our planet Earth in its smaller, faster orbit is swinging between the sun and Uranus around now. We’re now squarely in the middle of the best time of year to see this planet. Why? Because Uranus is now opposite the sun in our sky, rising in the east as the sun sets in the west, generally at its closest for the year.
Because Uranus is opposite the sun, it climbs highest up for the night at midnight (midway between sunset and sunrise) and sets in the west at sunrise. Not only does Uranus stay out all night long, but this world is now shining at its brightest best in our sky.
Even at its brightest, Uranus is still quite faint. It is barely perceptible as a dim speck of light to the unaided eye. At a magnitude of 5.67, Uranus shines no more brilliantly than the sky’s faintest stars. Given a dark sky free of light pollution, you might see Uranus with the eye alone – but only if you know right where to look for this distant world in front of the rather faint constellation, Aries. Uranus is in the southwest corner of Aries, hovering close to the Pisces border.
As good fortune would have it, this year the new moon – a moon most nearly between the Earth and sun for this month – falls on October 28, too, only about four hours before Uranus reaches opposition. The moon turns new at 03:38 UTC. That means there is no moonlight to wash out the 2019 Uranus’ opposition. Take advantage of these upcoming moon-free nights because next year’s opposition of Uranus will fall on the same date as the Blue Moon – the second of two October 2020 full moons – on October 31, 2020.
Even at its closest point to Earth, Uranus does not come particularly close to Earth. It’ll be just shy of 19 astronomical units away from Earth and 20 astronomical units from the sun. (By the way, one astronomical unit = sun-Earth distance). Visit Heavens-Above to find out the present distance of Uranus and the other solar system planets.
Uranus is quite easy to view with binoculars, through which it appears as a rather faint star. Again, you have to know precisely where to look to find the seventh planet from the sun. Your best bet is to find a good sky chart and then star-hop from the 4th-magnitude star Omicron Piscium, which is fairly easy to see with the eye alone on a dark night. Good luck!
Bottom line: Earth is closest to the seventh planet, Uranus, on October 27, 2019. Hours later, on October 28, Uranus reaches its yearly opposition, when it is most directly opposite the sun from Earth. The moon turns new on October 28, providing a dark night for viewing Uranus in front of the constellation Aries.