Have you ever seen Uranus with the naked eye? If not, moonless nights in late October and November offer ideal conditions to test your visual acuity and sky clarity. Uranus reaches opposition in the constellation of Aries on 28 October 2019 and lies 48° above the southern horizon at midnight as seen from the heart of the British Isles. Here is our guide to tracking down the seventh planet from the Sun.
Neptune reaches opposition on 10 September 2019 having returned to Aquarius, the constellation in which it was discovered in 1846. We show you how to locate the outermost planet using binoculars, a task made easier this month due to Neptune’s close passage to naked-eye star phi (φ) Aquarii on 6 September.
Mercury attains its maximum westerly elongation from the Sun on 26 August, meaning that the innermost planet is currently well placed for observation from the UK and Western Europe in the eastern sky around 40 minutes before sunrise. In addition to those in the evening sky, you might just see all five bright naked-eye planets this month!
Mercury is generally something of a challenge to observe, but the run-up to a particularly favourable easterly elongation occurring on 30 July provides ample opportunities for locating the innermost planet in the evening sky — particularly from the Southern Hemisphere, where a prominent celestial marker in the form of a 2-day-old Moon passes close by on 25 July.
Jupiter, the Solar System’s largest planet, reaches opposition on the evening of 7 April and lies closest to Earth for 2017 the following night. Don’t miss the 14-day-old Moon passing close by on the night of 10 April too. Here’s our comprehensive guide to what to see on Jupiter and phenomena of its bright moons for the month ahead.
Nine years ago, the International Astronomical Union (IAU) defined what it takes to be a planet, but left the classification of exoplanets for future consideration. With exoplanet discoveries now numbering close to 5,000, UCLA professor of planetary astronomy Jean-Luc Margot describes a simple “planet test” that can be readily applied to bodies orbiting the Sun and other stars.