March 2012 guide to the five visible planets Has there ever been a better month for watching planets? Hard to imagine. March 2012 ranks among the best! by Bruce McClure
All five visible planets in the March 2012 evening sky: Mercury (early March), Venus, Jupiter, Mars, Saturn (mid to late evening)
Wow, March 2012 is about as good as it gets for planet watching! Mercury, the innermost planet, makes its best evening appearance for the year in the Northern Hemisphere. All over the world, Mars shines at its greatest brilliance for the year – and moreover, the red planet stays out all night long. Plus, the brightest and second-brightest planets – Venus and Jupiter, respectively – come together for a stunning conjunction in mid-March. Saturn, the farthest and faintest visible planet, is nonetheless as bright as the brightest stars, and its glorious rings are surprisingly easy to view through a backyard telescope.
Four of the five visible planets – Mercury, Venus, Jupiter and Mars – pop out first thing at dusk. Saturn comes up later in the evening. All of these worlds should be easy to see, with the sole exception of Mercury, the innermost planet of the solar system. As darkness falls, Venus and Jupiter blaze away in the western sky, while fainter Mercury lurks beneath them, near the horizon. The red planet Mars is found low in the east at dusk and nightfall, beaming as the sky’s fourth-brightest “star,” after Sirius. Sirius, the brightest star in the nighttime sky, is only a touch brighter than Mars, and sparkles in the Northern Hemisphere’s southern sky at early evening.
Make Mercury a priority in early March, for the first week of March will feature the Northern Hemisphere’s best opportunity to catch Mercury in the evening sky until June 2012. First thing, after sunset, look for the dazzling planets Venus and Jupiter to burst into western twilight dusk. Then draw an imaginary line from Jupiter and past Venus to locate Mercury near the sunset point on the horizon.
Given an unobstructed horizon and clear sky, Mercury may become visible to the unaided eye about 45 to 60 minutes after sunset. Binoculars, though, make the search for Mercury so much easier, especially if the sky is murky near the horizon – as is so often the case. Mercury is actually as bright as a first-magnitude star, but the glow of evening twilight tends to subdue its brilliance. With Mercury setting a whopping 90 minutes after the sun at mid-northern latitudes, Mercury may well be yours to behold just before darkness falls in the first week of March.
Venus blazes like a lighthouse in the west at dusk in March 2012, as seen from all parts of Earth. In fact, all through March 2012, Venus and Jupiter – the sky’s two most brilliant planets – are the first “stars” to pop out at evening dusk, with Venus being the lower planet and Jupiter the higher in the first half of the month. After Venus and Jupiter have their conjunction at mid-month, Venus will become the higher planet and Jupiter the lower.
At mid-northern latitudes, Venus follows the sun beneath the western horizon about four hours after sunset all through March. Day by day, you’ll be able to watch Venus climb a little closer to Jupiter into the evening sky. It’ll finally meet up with Jupiter around mid-March 2012, when Jupiter and Venus will stage an amazing conjunction in the western twilight sky.
At the beginning of the month, Jupiter sets about five hours after the sun and Venus sets about four hours after at mid-northern latitudes. Every evening thereafter, watch for Venus to climb upward while Jupiter falls downward. By the end of the month, Jupiter will set about two and one-half hours after the sun yet Venus will still set a good four hours aftersunset.
Even on a moonlit night, it’s pretty easy to see Jupiter’s four largest moons with a backyard telescope. In their outward order from Jupiter, these moons are Io, Europa, Ganymede and Callisto. However, the positions of Jupiter’s moons – as seen from Earth – vary from night to night. Sometimes, a moon may be “missing” because it’s in front of or behind Jupiter. If you want to know which moon is which at a certain date and time, check out this handy almanac.
Jupiter photo credit: Velo Steve
Mars is rising in the east as the sun sets in the west in early March 2012. This is the other planet that will “wow” you on these March evenings. Mars reaches opposition on March 3, at which juncture this brilliant, ruddy world shines all night long, from dusk till dawn. Mars will become extremely noticeable in our sky in March – more noticeable than it’s been for the last two years. Very exciting!
Excitement is reaching to a fever pitch as Mars is now displaying its greatest brilliance in our sky. Mars started to retrograde (move westward) toward the star Regulus in the constellation Leo on January 24. Mars has been brightening ever since retrograde motion began, and its brilliance culminates with the Martian opposition in early March. Mars is now the fourth-brightest “star” in the nighttime sky, after the planets Venus and Jupiter, and the star Sirius, the brightest true star of the nighttime sky.
In early March 2012 – just as Venus and Jupiter are gearing up for their spectacular conjunction – Earth passes in between the sun and Mars. Mars comes closest to Earth for this two-year period and shines most brightly in our sky. This is the wonderful Martianopposition. Although this 2012 opposition will be a rather distant one for Mars, any Martian opposition is a grand event. It’s when we remember why we love this planet! So be sure to watch for Mars.
Use the moon to find Mars on the nights of March 6 and 7. Mars shines in front of the constellation Leo the Lion, but easily outshines the Lion’s brightest star, Regulus. You can also distinguish Mars from Regulus by color. Mars glowers in a ruddy hue while Regulus sparkles blue-white.
At mid-northern latitudes, Saturn rises in the east around 9 to 10 p.m. local time in early March 2012 – or at about the same time that Venus sets in the west. By the end of the month, Saturn is rising at nightfall – or approximately 8:30 to 9:30 local daylight saving time. Starting around mid-month, you can see Venus sitting low in the west as Saturn is rising in the east. Saturn appears highest in the sky around 3 a.m. local time in early March and about 2 a.m. local daylight saving time by the month’s end.
Saturn isn’t as dazzling as Venus or Jupiter. It’s not as exciting as Mars or Mercury. It’s the least conspicuous of the visible planets. In fact, early stargazers used to call Saturn “the oldest of the old sheep.” Thank goodness Saturn is fairly close to Virgo’s brightest star, Spica now. If you see two bright objects close together on the sky’s dome, one of them might be Saturn!
Use the moon to be sure you’ve identified Saturn and to see the beautiful pairing of the waning gibbous moon with Saturn and Spica on the night of March 10.
As a reminder, Mercury will only be visible in west after sunset during the first week or so in March 2012. Look for this innermost world in our sun’s family to lurk near the sunset point on the horizon about 45 to 75 minutes aftersunset. Try drawing an imaginary line from Jupiter through Venus to locate Mercury by the horizon during the last week of February.
Morning planets in February 2012: Mars and Saturn
Although Mars appears in the evening sky and Saturn at mid-evening, these two worlds light up the morning hours after midnight all the way till dawn throughout March 2012.
Bottom line: Excitement is building with respect to planets in Earth’s sky. Jupiter and Venus are edging toward a spectacular conjunction in March 2012. Mars is at its brightest and shines opposite of Jupiter and Venus as soon as darkness falls! This month, three planets – Venus, Jupiter and Mars – conspicuously stage themselves in the March 2012 evening sky, while Saturn more modestly displays itself from mid-evening until dawn. Mercury, the shyest of the five visible planets, will put on a good showing after sunset during the first week of March.