Telescopic Planets, Clusters and a Comet

Time to dust off those telescopes fellow sky watchers.


The planets are putting on a show in September.  Four out of the five classic or “naked-eye” planets are visible this month, two in the evening and two in the early morning.  Telescope viewers will also want to keep an eye on Mars as it will be visible in the same field of view as a star cluster and a comet.

In the evening sky we find Venus and Saturn.  Venus is easily visible in the sunset and Saturn becomes visible after twilight.  The crescent moon also joins the fun on the evening of September 8th.  On that evening the moon will be just two degrees to the left of the planet Venus.  On the evening of the 9th it passes six degrees from Saturn.  Venus and Saturn are also drawing together for a close conjunction.  The pair slowly draw close together until by the evening of the 18th they are just 2.5 degrees apart.  At that separation the pair should easily be visible in a low power, wide field eyepiece.

Turning to the pre-dawn sky we find other conjunctions.  The waning crescent moon passes den degrees below Jupiter on the morning of the 1st, and just seven degrees below Mars on the morning of the 2nd.  Jupiter will be very easy to spot in the pre-dawn sky, as it looks almost as bright as Venus does in the evening sky.  Mars is much dimmer but since it is the only bright point in that part of the it should be easy to spot.  The best way to locate mars is to find the twin stars Castor and Pollux in Gemini the Twins.  Mars is the orange colored point almost directly below Pollux.

The really amazing sight however occurs on the morning of the 8th.  Using binoculars or a telescope, focus in on Mars and look for a bright cluster of stars behind it.  This is M44, the Praesepe or Beehive Cluster.  Since M44 is very close to the ecliptic, any of the planets of our solar system can pass close to it.  Even a moderate powered eyepiece should show Mars and the Beehive in the same field of view.  This should also be an excellent opportunity for astrophotographers.

As if this weren’t enough, Mars will also be visible near comet ISON on the morning of the 20th.  Comet ISON is a sun-grazing comet, which means it will fly very close to the sun.  As it passes the orbit of Mars it passes what astronomers call the “frost line”, the line where solar radiation can cause the frozen gasses of the comet to sublimate (return to gas).  Whether the comet will be easily visible depends on how much it brightens as it passes Mars, something which no one can predict.  However, as it gets closer to the sun and more of the gasses sublimate it may brighten considerable, possibly even rivaling that of comet Hale-Bopp in the 1990’s.

September is a great month to get out the telescope and point them skyward.  Beginning observers have many great targets fro bright planets to a star cluster and hopefully even a bright comet.  Don’t miss these great opportunities to observe the sky and share it with your family and friends.



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