THE BIG THREE
The top sights to observe or image this month
DON’T MISS
Planetary conjunctions
BEST TIME TO SEE: Various times throughout the month
March plays host to a number of interesting conjunctions, starting off in spectacular fashion with a very close evening encounter between Venus and Jupiter. For the UK, the closest evening approach occurs on 1 March when the planets appear separated by just 36 arcminutes before setting.
The best view is around 19:25 UT when they are about 11° up and 38 arcminutes apart under dark sky conditions. Jupiter will be bright at mag. –1.9, but will be completely outshone by mag. –3.9 Venus.
Through a telescope, both can be seen in the same field, in a low-power eyepiece. As 38 arcminutes is about one-and-athird times the apparent diameter of the Moon, if you have an eyepiece that shows the Moon with plenty of space around it, this should show both planets clearly.
Venus is emerging into the evening sky after inferior conjunction on 22 October 2022. Consequently it is on the far side of its orbit and appears relatively small at 12 arcseconds with a gibbous phase of 85%. Jupiter will look almost three times larger at 34 arcseconds. On the evening of 1 March, all four Galilean moons are on display too, lining the event up for a great astrophoto.
Venus edges further east on the evening of 2 March, remaining close to Jupiter. At 18:15 UT, just after sunset from the centre of the UK, the pair are 45 arcminutes apart. The sky will still be light but these bright planets fare well.
If you can locate Venus shortly after the pair rise on 2 March, say around 09:00 UT, you’ll be able to catch them in a daylight sky at their narrowest separation of 30 arcminutes. Then at 10:00 UT during the morning of 24 March, Venus appears 57 arcminutes north of a slender 9%-lit waxing crescent Moon, 24° above the eastern horizon.
Venus’s eastward march has it pass just north of Uranus on 30 and 31 March. On the evening of 30 March, mag. +5.8 Uranus appears 1.2° south (below left from the UK) of Venus at 21:40 BST (20:40 UT). The following evening the distance increases to 1.7°, Uranus appearing south and slightly west (below and slightly left, from the UK) of Venus on this date.
Finally, on 26–29 March mag. –1.9 Jupiter and mag. –1.3 Mercury have a series of close evening encounters, coming closest on 27 and 28 March (1.5° then 1.6° apart), low above the western horizon 30 minutes or so after sunset.