This looping animation shows the sky low to the east-southeast horizon as seen from the centre of the British Isles from 23 October to 3 November at approximately 6am BST (or 5am GMT when daylight saving time ends on Sunday, 25 October). The interval between frames is one sidereal day, hence the stars appear fixed and the motion of the planets relative to the constellation Leo becomes clear. Venus reaches greatest westerly elongation from the Sun on the morning of Monday, 26 October — the same day it appears closest to Jupiter (1° separation). Eight days later, on 3 November, the brightest planet passes even closer to Mars (0.7° separation). For scale, the graphic is about 40 degrees wide, or twice the span of an outstretched hand at arm’s length. AN animation by Ade Ashford.In two former posts (see here and here), I drew your attention to the gathering of naked-eye planets in the east before dawn. Up until now, all of the Venus—Jupiter—Mars activity has occurred in the constellation Leo, but on Monday, 2 November magnitude+1.7 Mars crosses the border into Virgo. Hot in pursuit, magnitude -4.3 Venus also crosses the Leo-Virgo border the following morning when the two planets will be closest at just 41 arcminutes apart, or ~0.7 degrees. On 3 November, Mars will have a miniscule disc spanning just 4.3 arcseconds, or one fifth of Venus’ diameter.
However, you don’t need a telescope to follow the changing configuration of these three fascinating planets on successive days as it will be obvious to the naked eye or in binoculars. And if you have a low-power, wide-angle binocular, you can encompass all three in the same field of view throughout the period in question — if weather permits, naturally!
Inside the magazine
You can find out more about this month’s planetary peregrinations in the November edition of Astronomy Now in addition to a full guide to the night sky.
Despite more than seven weeks having passed since opposition, the Solar System’s largest planet Jupiter is still big and bright in the UK evening sky of May, highest in the south around 10pm BST. Find out about the phenomena of Jupiter and its moons that you can see from the British Isles for the remainder of the month, starting with a transit of Jupiter’s Great Red Spot on 19 May.
Mars hasn’t always looked like it does today. Some 3 to 3.5 billion years ago, the planet underwent a huge tilt of 20 to 25 degrees. The gigantic Tharsis volcanic dome, which started to form over 3.7 billion years ago, grew so massive that it caused Mars’ crust and mantle to swivel around, shifting the Tharsis dome to the planet’s equator.
Observers in the UK with a clear sky high to the south-southeast shortly after midnight on Sunday, 12 January 2020 can see the 16-day-old waning gibbous Moon just three-quarters of a degree north of the beautiful open star cluster Messier 44, otherwise known as Praesepe, or the Beehive Cluster.
