As June draws to a close, largest planet Jupiter is an unmistakable magnitude -2.5 naked-eye object found highest in the southern sky of the British Isles close to 11:30pm BST. By 13 July, when the planet lies close to the 11-day-old Moon, the pair attain their peak altitude due south around 10:45pm BST.
Jupiter’s current location in the southern reaches of the constellation Ophiuchus does mean that the planet gets no higher than 14 degrees above the southern horizon for an observer in the heart of the UK, but on nights of calm air with good seeing there are still wonders to behold with telescopes of apertures as small as 7.6-cm (3-inch) at magnifications of 100× or more.
Great Red Spot
While Jupiter’s Great Red Spot (GRS) appears to have temporarily ceased its flaking activity (see this story), observers should keep a keen eye on this Earth-sized anticyclonic storm in the Jovian atmosphere.
The table at the bottom of this page lists the best times to see the GRS for observers in the British Isles and those parts of Western Europe at a similar longitude (e.g., Spain, Portugal, Central and Western France). For other locations worldwide, consult our interactive online Almanac, ensuring that the ‘Add phenomena of Jupiter?’ checkbox is ticked.
The largest planet always has more to offer than cloud features in its constantly churning atmosphere. Jupiter is a veritable miniature solar system in its own right, with a family of 79 known natural satellites. The four large Galilean moons — Io, Europa, Ganymede and Callisto — regularly pass in front of (transit), are eclipsed (passing into shadow) or occulted (hidden) by Jupiter.Io, Europa and Ganymede display transits, shadow transits (where their shadows appear as inky black dots drifting across Jupiter’s cloud tops), eclipses and occultations throughout July, as summarised for the British Isles and similar longitudes in the table below.