Jupiter and Saturn

Knowing when & where to look is the key to success in recognizing the difference between which is a star and which is a planet even for such bright planets as Jupiter and Saturn and it is hoped that these charts will guide the observer in identifying them (click on the chart for a larger view).

These charts show the motion of both planets against the background stars and gives an idea of how far each moves across the sky during the year. The yellow path indicates the direction of Retrograde (left to right) motion of the planets and the blue path indicates the direction of Prograde (R-L or normal) motion. The orange section of each planets path are the time when they are too close to the Sun to observe easily and Conjunction with the Sun is shown by the large yellow disk. Planets positions are shown for 1st of the month.

Jupiter

Jupiter begins the year in the early evening sky in Pisces but rapidly moves into Aries during the first week of January. Over the next couple of months it moves further along the ecliptic moving south of the main stars of Aries but as it does so it is also getting lower in the evening twilight sky. It should become lost in the brightening twilight in late April and is in Conjunction with the Sun on May 13th and so not visible. Jupiter is bright though and emerges into the morning twilight during early June but will be very low in bright twilight at first. It will lie below the bright open cluster M45, the Pleiades or Seven Sisters cluster for the first couple of weeks of June. It slowly improves as it moves through Taurus over the next few months being visible in the morning sky and reaches the only stationary point of the year on October 13th when it then begins retrograde motion. Jupiter is at Opposition on December 3rd and is magnitude -2.8. It is then visible all night and becomes better placed for viewing in the evening sky.

Saturn

Saturn lies in Virgo for much of the year and begins 2012 in the morning sky. It is stationary on February 8th after which it is in retrograde motion reaching Opposition on April 15th when it will be magnitude +0.2 After this it is then visible all night and so well placed to view. Retrograde motion ends when it reaches its stationary point on June 26th when it resumes normal motion (Prograde). By then it lies in the evening sky and on August 17th it is conjunction with Mars. Around late September Saturn becomes lost in the evening twilight and solar glare as it heads for Conjunction with the Sun on October 25th. It emerges into the morning sky by mid November and remains a morning object for the rest of 2012. Note that for both charts the actual position of the Sun against the stars at conjunction is shown but that the solar disk is not shown to scale with the chart.

At their oppositions, Jupiter is very bright at magnitude -2.6 whilst Saturn is reasonably bright at magnitude +0.7 so both should be easily identifiable using these charts.

Finder charts for Jupiter and Saturn for the year