Last month mars returned to opposition after a two-year hiatus.  You may have heard that mars reached its maximum size on January 29, but a mars opposition lasts longer than just one night; in fact mars is an excellent object to observe throughout February and March this year.  Mars begins February with an apparent diameter of 14", shining at magnitude -1.3.  It is best visible around midnight.   By the 15th it will still be a very nice 13" in diameter.  On February 28 it will have shrunk to 12" and my March 31 is will be down to 9".  Throughout this time Mars will be one of the brightest "stars" in the sky.  The reddish color is difficult to miss.  Look for it rising in the east at sunset and high in the sky around midnight.  

The best views of mars come at oppositions, which occur roughly every 26 months.  These are the times when mars is closest to the earth, which translates to mars looking larger in the eyepiece.  If you want to see the features of the red planet, the larger it appears the better.  Not all oppositions are the same; the best oppositions occur every 16 years or so.  During the opposition in 2003 mars appeared its largest in recorded history, reaching at a diameter of 25".  Mars will be somewhat smaller at this opposition, with a maximum diameter of 14".  Unfortunately this is pretty much rock bottom in the cycle, with Mars nearly half the size as seen in 2003.  In 2012 it will be about the same size as this year.  It won't be until 2014 that it starts getting larger again.

Mars is simulated over five oppositions above.  Not only does the size of mars change as seen in the eyepiece, but we see it from different perspectives.  The current opposition features the northern polar cap.  

The enemy of the mars observer is the earth's fickle atmosphere.  Always look at mars when it is highest in the sky.  As February begins it will be best around midnight; by March it will be best in the late evening.  For northern hemisphere observers mars will be high in the sky for really good views, unlike 2003.  On nights of excellent seeing much detail should be visible.  Be sure to take your scope outside well before you observe and point it at the sky to let it cool to the same temperature as the surroundings.  Most scopes will take an hour or more to cool.

Many people believe that you need a dark sky to observe mars, but this isn't the case!  Mars can be observed from your back yard as long as your back yard has steady air.  Try not to observe mars over a building or any other significant source of  rising heat.

Some nights will simply have more steady air (better seeing) than others, so it is important to get out and observe on as many nights as possible.  Have a look at the bright star Sirius.  Is it dancing and flickering, perhaps even changing colors?  The more steady it shines the better the seeing.  Mars itself may be nothing but a blur in your scope, but even on these nights of poor seeing patience can really pay off.  If the seeing is very poor have a look at something else for a while and come back later.  In any event, be prepared to stare at mars for at least an hour.  Try to get as comfortable as possible.  Sit down if you can.  Even on nights of poor seeing there are often moments of great clarity.  These brief moments are when the details become apparent!

Using red or orange color filters can help bring out the dark features.  Wratten 25 or 23A filters are often recommended.  A blue or violet filter can enhance the cloud features.

What to look for

More transient features are the clouds that come and go.  They appear as white spots that often cover the same areas at the same time of the martian day.  With larger instruments it is possible to see the clouds that often top the great martian volcanoes in Tharsis.

Dust storms can also come and go.  They appear as yellowish clouds that start out small, yet may possibly grow to encompass the entire planet.  There is currently no way to predict when or where these dust storms will appear.

Because the martian day is only 40 minutes longer than the earth's, you will be presented with the same side of mars observed at the same time on successive nights.  If you observe every night at 1 AM, for instance, it will take over 40 nights to see the entire planet slowly rotate into view.  A passage of five days will reveal a 1/8th turn of mars in the eyepiece.  On the other hand, you can see a 1/8th turn by observing mars 3 hours later.

Suggestions for Observing Projects

•   Look for transient clouds from day to day
•   Look for changes in the dark markings, particularly in Syrtis Major, Solis Lacus and Sabaues Meridiani
•   Watch for dust storms.  They may grow from yellow clouds to eventually encompass the entire planet, obscuring our view of the other features

All simulations via our SkyTools 3 software.