Planetary Notes
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Looking Forward; August / September 2022
In August Mercury has an excellent evening apparition for the southern hemisphere but is disappointingly low as seen from the UK. Greatest eastern elongation from the Sun is on 27 August but you may have a better chance of catching Mercury here in the first two weeks of August if you look due-west soon after sunset. Although Mercury sits slightly above the ecliptic the elevation of both sink in the western sky as the month progresses and Mercury may be too low for many to observe.

The planet moves into the morning sky in late September and is very close to Venus on the 26th but the pairing is also close to the Sun and UK observers are unlikely to glimpse either before sunrise.
Venus is in the morning sky throughout this period and its orbit ascends above the ecliptic on 02 August. This rise somewhat counters its steady move closer to the Sun, thus slightly prolonging its visibility. At magnitude -3.9 it will be very obvious rising in the north-east around 0244UT in early August and will reach nearly 15 degrees of elevation before sunrise. Mid-period Venus rises at 0400 UT, still just as bright and is still above 10 degrees up in the east at sunrise; after this it sinks fairly rapidly towards the Sun and becomes effectively unobservable.
Mars is steadily improving throughout August and September. On 02 August Mars rises ENE around 2310UT for mid-UK latitudes and is very close to Uranus; sitting 1.3 degrees below it. The pair climb to nearly 40 degrees above the ESE horizon by the start of morning civil twilight. By late August Mars rises around 2155UT, sitting above and slightly west of Aldebaran with Mars noticeably brighter than this red ‘eye’ of Taurus. By civil twilight Mars is nearly 55 degrees up in the south-east and will show an obvious gibbous phase. At 9.8 arcseconds from pole to pole, significant detail should be on view. By late September Mars can be followed from 2040UT, rising between the horns of Taurus, and will transit, due south at 0445UT, still in nautical twilight and around 60 degrees up.

Jupiter rises ahead of Mars, due east at 2155UT in early August. At magnitude -2.7 it will be very obvious and it reaches significant elevation in the early hours, ‘though not as high as Mars. Initially south-transit is in daylight but by mid-August transit is in nautical twilight, around 0305UT with Jupiter sitting 40degrees high. Early in September south-transit is in full darkness at 0155UT and on the 26th Jupiter comes to opposition, due-south close to midnight UT and the planet can be followed through all of the hours of darkness. Shining brightly at magnitude -2.94 it will present a disk fully 49.9 arcseconds across and with good ‘seeing’ conditions will show simply amazing detail.

As Mars follows Jupiter, Jupiter follows Saturn, which comes to its own opposition on 14 August. Sadly Saturn will not sit nearly as high in the south at transit, around 22 degrees up for much of the UK, but this is considerably better than during its last opposition and Saturn is certainly not to be missed. Shining at +0.3 the planetary disk will stretch 18.8 arcseconds across at the equator and the bright rings to 43.7 arcseconds; almost as wide as the face of Jupiter. If you can observe Saturn for several days around opposition, look a change in the ring brightness. At this time all the shadows cast by fragments within the rings are hidden behind the fragments themselves causing the rings to noticeably brighten; this is the Seeliger Effect or the Opposition Surge.  In September Saturn is still accessible throughout the evening, not setting till well after midnight even late in the month.

Of the Ice giant outer planets, Neptune rises ahead of Uranus and sits a little to the right (west) of Jupiter in an empty region below the westernmost fish head asterism within Pisces. Initially Neptune transits in early twilight but by mid-period transit occurs at 0110UT and in full darkness. Opposition happens on 16 September when Neptune’s tiny 2.5 arcsecond disk sits 35 degrees high, due south at midnight UT. At magnitude +7.8 you will need a small telescope to find it.

Magnitude +5.7 Uranus sits above Mars in early August and rises with it to similar altitudes. Mid-period onwards look for Uranus between the Pleiades and the head of Cetus. Transit is at around 55 degrees up at 0420UT in late August and 0235UT in late September.