The beautiful ringed planet Saturn is now in its period of apparent retrograde motion and will soon achieve Opposition relative to the Sun. I’ve created a chart demonstrating Saturn’s 2006-07 retrograde loop in ecliptical coordinates. The graphic also shows the various aspects of Saturn’s rings from 1995 to 2017. It can be seen at http://www.curtrenz.com/astronomical.html
Around the time of Opposition, Saturn will be rising near sunset, transiting the southern meridian around local midnight, and setting near sunrise. The following are my predictions of oppositional extremes during Saturn’s current synodic cycle (the period for Earth lapping Saturn: 1.035 years.) Saturn should achieve its greatest brilliance at magnitude 0.0 on 2007 FEB 06 at 04 hr UT. That is similar to the magnitude of Arcturus, the brightest star in the northern celestial hemisphere. Saturn's closest approach to Earth of 8.20035 AU will come on FEB 10 at 15 hr UT. Shortly thereafter it will achieve all three types of Opposition:
FEB 10 at 18:42 UT: Opposition in Celestial Longitude
FEB 10 at 19 hr UT: Greatest Elongation of 178.7°
FEB 11 at 04:30 UT: Opposition in Right Ascension
Its ecliptical latitude at those times will be N 1.3°, and its declination will be N 15.5°. That means for northern hemisphere observers, at meridian transit Saturn will culminate at an altitude that is equivalent to one’s co-latitude (90° minus one’s geographic latitude) plus 15.5°. For example, I live at N 42.1°, therefore it will culminate at 63.4° above my southern horizon.
At Opposition, Saturn’s apparent equatorial angular diameter will be 20.2 arcseconds and its rings will cover 45.8 arcseconds. Its axial tilt relative to Earth will be –13.9°. That means we will still be viewing the southern side of its rings, which orbit above its equator. The tilt will reach its extreme of –15.4° for this synodic cycle on APR 18. The extreme tilt for its 29.5-year orbital cycle came in 2003 at -27.0°. The rings will seem to disappear around the period when Earth moves through Saturn’s equatorial/ring plane on 2009 SEP 04.
Around the time of Opposition, Saturn will be rising near sunset, transiting the southern meridian around local midnight, and setting near sunrise. The following are my predictions of oppositional extremes during Saturn’s current synodic cycle (the period for Earth lapping Saturn: 1.035 years.) Saturn should achieve its greatest brilliance at magnitude 0.0 on 2007 FEB 06 at 04 hr UT. That is similar to the magnitude of Arcturus, the brightest star in the northern celestial hemisphere. Saturn's closest approach to Earth of 8.20035 AU will come on FEB 10 at 15 hr UT. Shortly thereafter it will achieve all three types of Opposition:
FEB 10 at 18:42 UT: Opposition in Celestial Longitude
FEB 10 at 19 hr UT: Greatest Elongation of 178.7°
FEB 11 at 04:30 UT: Opposition in Right Ascension
Its ecliptical latitude at those times will be N 1.3°, and its declination will be N 15.5°. That means for northern hemisphere observers, at meridian transit Saturn will culminate at an altitude that is equivalent to one’s co-latitude (90° minus one’s geographic latitude) plus 15.5°. For example, I live at N 42.1°, therefore it will culminate at 63.4° above my southern horizon.
At Opposition, Saturn’s apparent equatorial angular diameter will be 20.2 arcseconds and its rings will cover 45.8 arcseconds. Its axial tilt relative to Earth will be –13.9°. That means we will still be viewing the southern side of its rings, which orbit above its equator. The tilt will reach its extreme of –15.4° for this synodic cycle on APR 18. The extreme tilt for its 29.5-year orbital cycle came in 2003 at -27.0°. The rings will seem to disappear around the period when Earth moves through Saturn’s equatorial/ring plane on 2009 SEP 04.
For astronomical graphics, including
monthly wallpaper calendar, visit:
CurtRenz.com/astronomical
Curt Renz
