PICK OF THE MONTH
Mars
Best time to see: 1 March, 19:20 UT Altitude: 50˚
Location: Taurus
Direction: Southwest
Features: Albedo markings, polar ice caps, weather Recommended equipment: 150mm or larger
As far as the UK is concerned, the planets are rather poor at present, all but Mars being hampered by their proximity to the Sun in the sky. However, despite currently being the most northerly planet, the appearance of Mars continues to deteriorate, it being unable to reach its highest position in the sky in darkness.
At the start of March, Mars shines at mag. +0.9 and presents a diminishing disc 6.4 arcseconds across through the eyepiece. By the end of the month, the Red Planet will have dimmed further to mag. +1.3 and through the eyepiece of a telescope shrinks to 5.3 arcseconds. It tracks east throughout the month, passing across the northern part of the constellation of Taurus, the Bull.
At the beginning of March, it is located south of the Pleiades open cluster, M45, lying 2.5˚ from the cluster on the 4th. It sits 7˚ north of orange giant Aldebaran on the evening of 19 March, the date when Mars has its monthly visit from the Moon. On this occasion, the Moon will be visible between Mars and Aldebaran, roughly one third of the way along the line joining both objects, starting from the planet. The Moon will appear as a 33%-lit waxing crescent on this date.
The small appearance of Mars’s disc through the eyepiece is down to an increase in distance between Earth and the Red Planet. Having enjoyed an excellent opposition last October, Mars is now entering a slow period where it’s too small for serious observation. The next opposition occurs on 8 December 2022, when Mars reaches 17 arcseconds across and gets to a good declination for the UK in Taurus. Although smaller in maximum diameter than the 2020 opposition, in 2022, Mars attains an altitude of over 60˚ when due south.
Mercury
Best time to see: 6 March, from 30 minutes before sunrise Altitude: 1˚ (extremely low) Location: Capricornus Direction: East-southeast Mercury is poorly placed in the morning sky all month, despite reaching greatest western elongation on 6 March. Jupiter, Saturn and Mercury appear together this month; on 5 March, mag. +0.2 Mercury lies 19.5 arcminutes from mag. –1.8 Jupiter while mag. +0.9 Saturn lies 8.8˚ to the west. On 10 March, Mercury lies 4.3˚ east of Jupiter with a 10%-lit waning crescent Moon sitting 11˚ to Mercury’s southwest. The Moon rises 30 minutes before the Sun on this date, Mercury appearing 10 minutes before the Moon, but you’ll find the bright morning twilight will make this a tricky observation.
Venus
Venus reaches superior conjunction on 26 March when it transitions from being a morning to an evening planet. Despite this and a favourable steep ecliptic angle in the west after sunset, Venus is unlikely to be seen throughout March.
Jupiter
Best time to see: 31 March, 40 minutes before sunrise Altitude: 4˚ (very low) Location: Capricornus Direction: East-southeast Jupiter rises approximately 45 minutes before the Sun at the start of March, but a shallow ecliptic angle with the eastern sunrise sky at this time of year keeps its location is poor.
During March in the morning sky at sunrise, Jupiter just doesn’t achieve sufficient altitude to be easily observable. It has a very close encounter with mag. +0.2 Mercury on the 5th, both planets separated by just 19 arcminutes as they pop up above the east-southeast horizon. A 10%-lit waning crescent Moon joins the scene on 10 March, but is more poorly placed than Jupiter! On 31 March, despite rising 70 minutes before the Sun, Jupiter doesn’t quite make 9˚ above the horizon before sunrise.
Saturn
Best time to see: 31 March, 50 minutes before sunrise Altitude: 3˚ (very low) Location: Capricornus Direction: Southeast During March, Saturn can be seen crawling further from the Sun in the morning sky, but despite this the planet remains low. It appears 8˚ to the west of Jupiter on the 1st, a separation that increases to 12˚ by the month’s end. A 17%-lit waning crescent Moon sits to the west-southwest of Saturn on the morning of the 9th. At the month’s end Saturn attains an altitude of 8˚ above the southeast horizon before the onset of morning twilight.
Uranus
Best time to see: 1 March, 19:40 UT
Altitude: 30˚
Location: Aries
Direction: West-southwest The observing window for Uranus closes during March as the evening twilight expands to engulf this distant world. Located in southern Aries, Uranus appears 30˚ up as true darkness falls at March’s start. By the month’s end it has an altitude of less than 5˚ by the time true darkness arrives.
Neptune
Not visible this month – solar conjunction on 10 March.