Guide to the night sky in March - dance of the planets
Wherever you live, March is a great time to gaze at the night sky.
Not only are the skies still moderately dark across the world and so constellations are relatively easy to identify, but this month sees a real spectacle from our planetary neighbours.
Mercury, Venus, Mars, Jupiter and Saturn all put in an appearance in the evening sky during March and on occasions quite spectacularly.
On the 3rd March, the red planet Mars is said to be at opposition. This means it will lie opposite the Sun in the sky so that as the Sun sets, Mars rises. It also means if you are struggling to identify it, then you can take a look at midnight and the red 'star' that lies due south will be Mars.
Its worth pointing a telescope at Mars if you have one to see if you can pick out any of the subtle surface detail such as the polar ice caps. Unlike Earth, these polar caps are made of carbon dioxide ice rather than water ice.
On the 7th of the month there is another good opportunity to help you locate Mars as it will lie 10 degrees above the Moon (see main image above). Fortunately no matter how big or small you are, clenching your fist at arms length will give you a measure of about 10 degrees against the sky.
The rather elusive inner planet Mercury gets to its highest in the evening twilight on the 6th of the month but even then, its only 10 degrees above the horizon. Remember to use a clenched fist at arms length to help you find it. Even though at its highest, it will be difficult to pick out against the twilight sky so persistence and a very clear western horizon are needed.
Night sky 6th March: Mercury, Venus and Jupiter. Image credit: Virtualastro
On the 11th of March there is a great opportunity to try and pick out majestic Saturn with its stunning ring system. Its visible as a yellow/white 'star' in the constellation of Virgo and is the last of the planets to rise, but on the 11th it will lie 7 degrees above the Moon. You will need a magnification of at least 20x to be able to make out the rings so unless you have a powerful pair of binoculars, you will need a telescope to show them. It doesn't have to be an astronomical telescope, even a bird-watching telescope should be powerful enough to show them as they encircle the planet.
Night sky 11th March: look out for Saturn above the Moon. Image credit: Virtualastro
The planets that really steal the show toward the end of the month though are Venus and Jupiter. For the last few weeks we have already been able to enjoy the two planets in the west during early evening and that continues through March.
Venus, the second planet from the Sun, shines as the brightest object in the west after sunset and really can't be missed. Its so bright that it's often mistaken for a UFO!
Surprisingly, although Venus is the second planet from the Sun, it’s hell-like with a surface temperature of 462 degrees Celsius - hot enough to melt lead. The Sun's heat is unable to escape because its trapped by a thick carbon dioxide atmosphere its actually the hottest due to excessive, natural greenhouse gasses.
Whilst a telescope won't show you any detail on the surface because of the thick dense atmosphere, you will notice that the planet shows phases just like the Moon. Its the changing relative positions of the Sun, Earth and Venus that alters how much of the illuminated portion of the planet we can see.
The second brightest object in that part of the sky is Jupiter. To the unaided eye it just looks like a bright star but powerful binoculars or a small telescope reveal a whole new world. It is the largest of the planets and is made almost entirely of gas.
Through a small telescope you will be able to see four of Jupiter's moons: Io, Europa, Ganymede & Callisto forming a line on either side of the planet.
Watch them over a few nights and you will see their positions move as they orbit the giant planet. A larger telescope will be able to reveal detail in the gas atmosphere of the planet and perhaps even the Great Red Spot which is a large hurricane three times larger than Earth.
As the two planets continue their journey around the Sun they currently appear close together in the sky.
On the 14th March Venus and Jupiter get to their closest approach and will lie just 3 degrees apart (one finger at arms length covers 1 degree of the sky) and the Moon joins in the display toward the end of the month on the 26th when it will be just below Venus.
Night sky 26th March. Image credit: Virtualastro
Even if you are new to astronomy, the planets offer really easy targets and to see them in the sky you don't need any equipment. If you want a closer view then a telescope is needed but if you don't have one don't worry.
As the planets dance around the sky during March, just sit back, watch the show and don't miss the finale of Jupiter, Venus and the crescent Moon setting in the twilight.
Notes. Images show how the planets look from the northern hemisphere. For views where you are, in the southern or northern hemisphere, check out astronomer Mark Thompson's "The Sky Where You Are"