Sky Notes for March 2012, with James Abbott
The long awaited conjunction between Jupiter and Venus takes place this month, with the two planets at their closest on the evenings of the 12th and 13th. Regular observers will have seen the gap between the two planets close over recent months and during the evenings around the conjunction Venus appears to move past Jupiter, a real time view of our dynamic Solar System.
With a closest separation of just 3 degrees, the two planets will be within the field of a pair of typical binoculars.
The best time to look will be between 7pm and 9pm with the two planets setting at around 10pm in the West.
On the evenings of the 25th and 26th of March the young crescent Moon will pass by both planets, producing another close encounter. Spring is often a good time to see the “dark” portion of the young Moon lit up by Earthshine.
By mid-month, looking to the South East, Saturn is about 20 degrees up by 11pm. To the right of it and similar in brightness will be Spica, the brightest star in Virgo.
The Moon is Full on the night of the 7th/8th, passing about 10 degrees below Mars. The Red Planet reaches its closest point to the Earth on the 4th at a distance of about 63 million miles. This is much further than the closest approaches possible and so in a telescope the disc of the planet is modest at 14 arc seconds. Nevertheless, it will peak at mag -1.2 and at nearly 50 degrees in altitude when due South, Mars will be above the worst of the turbulence that causes bad seeing.
Daylight increases at its fastest for the whole year in March and with the clocks going forward to BST on Sunday 25th March, the change is dramatic. By the end of the month, Sunset is at 7.30pm and it is not fully dark until 9.30pm BST.
The stars appear to march in tune with the changing clocks. By late evening at the end of March, the familiar winter constellations are setting in the West, but in the North East the brilliant blue/white star Vega is already on show, a herald of the summer to come.
Also in the North East at the start of March is comet C/2009 P1 Garradd. The comet has been putting on a show for months and remains well placed in the late evening throughout March. Its starts the month at around mag 6.5 and from dark sites it is possible to make out parts of its extensive complex of tails even in binoculars and small telescopes.
James Abbott is an astronomer, NEAS member and CfDS Regional Information Officer.