Around 6:30am GMT on Friday 25 November, as nautical twilight starts for the centre of the UK, the 25-day-old waning crescent Moon lies just 2½ degrees away from largest planet Jupiter low in the southeastern sky. This juxtaposition of the two brightest celestial objects in the dawn sky will be nicely framed in a typical binocular. Look for fourth-magnitude star theta (θ) Virginis in the same field of view, a double star in small telescopes. AN graphic by Ade Ashford.For early risers in the British Isles, Jupiter can be found in the constellation of Virgo low in the east-southeast from 4am GMT. For those of you not prepared to brave the cold of such small hours, the 25-day-old waning crescent Moon lies within the same binocular field of view as the magnitude -1.8 largest planet at the start of nautical twilight on Friday 25 November. Look low in the southeast around 6:30am GMT to see this beautiful conjunction.
The configuration of Jupiter’s four Galilean moons Io, Europa, Ganymede and Callisto in the UK dawn twilight of Friday 25 November 2016 as seen with an erect-image telescope (north is up and east to the left). AN graphic by Ade Ashford.In binoculars and small telescopes you will also notice fourth-magnitude star theta (θ) Virginis a degree (or two lunar diameters) below the Moon. This object, also known as 51 Virginis, is a multiple star with components of magnitude +4.4 (a close double) and +9.4 separated by 6.4 arcseconds.
Turning our attention back to Jupiter on the UK morning of 25 November, owners of supported powerful binoculars and telescope owners can see all four of the planet’s Galilean Moons — Io, Europa, Ganymede and Callisto. Observers in possession of quality instruments of 70mm aperture and larger capable of 150x magnification or more can observe transits, eclipses and shadow transits of these large Jovian moons on other mornings. You can obtain detailed predictions via our interactive online Almanac.
As a taster for observers in the British Isles, Io is eclipsed by Jupiter’s shadow at 7:17am on 22 November; the shadow transit of Io ends at 6:47am on 23 November; Io emerges from occultation by Jupiter at 4:51am on 24 November and Ganymede is eclipsed by Jupiter’s shadow at 5:19am on 26 November. Transits of Jupiter’s Great Red Spot (GRS) occur at 7:48am on 26 November, 5:18am on 29 November and 6:57am on 1 December (all times GMT).
Inside the magazine
For a comprehensive guide to observing all that is happening in next month’s sky, tailored to Western Europe, North America and Australasia, obtain a copy of the December 2016 edition of Astronomy Now.
Inner planets Mercury and Venus are currently approaching conjunction, low to the southwest horizon shortly after sunset. If you have an extra clear sky, then Mars completes the scene.
The Moon’s thin atmosphere contains neon, a gas commonly used in electric signs on Earth because of its intense glow. While scientists have speculated on the presence of neon in the lunar atmosphere for decades, NASA’s Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft has confirmed its existence for the first time.
In the pre-dawn twilight of Tuesday, 1 March, the 21-day-old waning gibbous Moon acts as a convenient celestial guide to planets Saturn and Mars. For observers in the centre of the British Isles, the best time to see this triple conjunction is shortly before 6am GMT, when the trio are highest in the sky to the south.
