Saturday, March 10, 2012

Skywatch: A Celestial Show in March

For the past few weeks there have been two bright objects in the western sky after sunset.  These two bright stars are in fact planets; Venus and Jupiter.  Both planets appear to be close to each other even though they are hundreds of million miles apart.  The brighter of the two is Venus.

Venus and Jupiter form a spectacular pairing in the evening sky during mid-March. These scenes show the sky's appearance looking west about an hour after sunset. A third planet, Mercury, can be glimpsed just above the western horizon.  Image Credit: Sky and Telescope.

The weather cleared for the weekend of March 10th and this has provided great viewing conditions.  There will be plenty of opportunities to view this in the coming week as there will be little chance for rain.  Venus appears to be the larger planet, but in fact Jupiter is the much larger planet.  Jupiter is 522 million miles from Earth while Venus is about 76 million miles away.

This celestial show will have a second act toward the end of March.  That is when a rising crescent moon will enter the picture as shown in the graphic below.

Here is the scene looking west about an hour after sunset in late March. Over four evenings, a waxing crescent Moon will move upward past Jupiter and Venus.  Image Credit:  Sky and Telescope.

Notice the change in position between Venus and Jupiter.  Their closest apparent approach will be on Wednesday, March 14, when the planets will be just 3 degrees apart.  The two planets are unmistakable since they are the two brightest objects in the western sky after sunset.

This is a great time of the year to get out and stargaze.  The air is dry and the nights are cool.  Thus, the atmosphere is more stable and the objects look a little crisper.  If you are interested in stargazing as a hobby, a very good source of information is Sky and Telescope.  I have read this magazine for about 50 years.  It has changed over time, but it has always had great graphics and great information.