This is a great month for observing planets – with up to five bright planets visible. March marks also the end of Venus as an evening star. The brilliant planet has dominated evening skies over the past few months from 45 million kilometres away; but as it continues to orbit the sun it passes through a position known as inferior conjunction. At this point, in the last week of the month, it will transition from the evening sky to the morning one.
The size of Venus grows so much during the month that it is said that sharp-eyed observers are able to make out the crescent shape with the naked eye. Venus also shines so bright that in very dark locations it can also cast shadows onto light-coloured backgrounds, such as on whitewashed walls. Do not miss the opportunity to see it, for a few days at the end of the month, both after sunset and before sunrise.
Mercury takes over the evening skies as it puts on its own show during March with its best apparition for this year. It climbs into view from mid-March onwards, and by the end of the month the planet should be an easy target to spot after sunset, above the western horizon. Mercury is usually hard to see as it shines at a low altitude. The crescent moon will be in the planet’s vicinity at the end of the month, making it much easier to identify. Using a smartphone app will ensure you are actually looking at the solar system’s smallest planet.
Other planets visible this month are Mars, Jupiter and Saturn. Mars continues to shine, much fainter than Venus, in the evening skies to the upper left of Mercury and Venus.
Jupiter makes a comeback to the night skies after a few months’ absence. By the end of the month it will start rising shortly after sunset, close to the whitish star Spica in Virgo. It is now quickly approaching opposition (its closest point to the Earth at a distance of 680 million kilometres) when its brightness will be exceeded only by that of Venus and the moon.
Saturn rises later, after midnight. For the past few years the ringed planet been in the vicinity of red supergiant star Antares, in Scorpius. Saturn moves quite slower than other planets, taking a little less than 30 years to complete one revolution around the sun.
Spring returns on the morning of March 20 – when day and night are equal (equinox) everywhere around the Earth as the nights keep on getting shorter and shorter – as the sun crosses northwards over the equator.
This month’s appearance of distant planets in our skies reminds me of the headlines made a few days ago with the discovery of even more planets around far-away stars. With the latest discoveries the amount of exoplanets goes up to over 3,500 (the first one was discovered just in 1995) – but in spite of this, Earth is the only place where life as we know it, has been found till now.
Highlights in March
■ Brilliant planet Venus switches from the evening sky into the morning sky, the best chance in eight years to see this.
■ Jupiter returns to the earlier part of the night, shining brightly in Virgo.
■ Orion constellation shifts from the south to the southwest after sunset, Leo climbing up in the east – both signs that the Earth is moving along its orbit hence its view out into space is changing.
Astronomical events that will take place during this month
Today: 3am - Moon 0.2° north of Aldebaran; Noon - First quarter moon.
March 7: Midnight - Mercury in superior conjunction.
March 10: 11pm - Moon 0.8° south of Regulus.
March 12: 3pm - Full moon.
March 14: 8pm - Moon 2.5° north of Jupiter.
March 20: 10am - Moon 3° north of Saturn; 10.28am - Vernal equinox; 4pm - Last quarter moon.
March 25: 10am - Venus in inferior conjunction.
March 26: 2am - Start of Summer Time.
March 28: 3am - New moon.
March 29: 7am - Moon 7° south of Mercury.
March 30: 1pm - Moon 5° south of Mars.
Alexei Pace is a member of the Astronomical Society of Malta.