Saturn approaching Spica

Date: April 12th
Time: 9:44(.44) PM

Brief

   Saturn, which is almost at opposition, shines brighter than any of the stars in Virgo, where it is moving east to west in retrograde.  As we have watched it over the last two months, it has more quickly caught up to the hot, white-blue star Spica.  After being about 7º apart in late January and early February, when Saturn was stationary and started retrograde, the planet and star are now only a little 5º apart while still getting closer.  As Saturn ends its retrograde in about another two months, it will spend many weeks slightly under the 5º mark, before finally moving further through Virgo and not catching back up with Spica again for another 28 years.  Saturn's revolution period last about a year later than that, although we subtract a year or so for the back-and-forth time near a star.

Detailed

  Why the strange time listed at the beginning of this entry, and shown in the images?  It has little to do with when Saturn is high enough to see out of atmospheric pollution.  Instead, it marks when Spica and Saturn are exactly at the same altitude for the evening, as seen from our location.  The time for this changes slightly daily, as Saturn (1) rises about four minutes earlier each evening, and (2) changes gradually in declination in relation to Spica.  Look at the azimuth grid here, for an example of that.
 

There is no real significance of waiting for two naked-eye objects to be at the same altitude.  However in the daytime, if it is known, it could help find harder-to-see planets.  For example, a few weeks ago when Jupiter and Venus were near conjunction, Venus would become visible first just before the Sun set, in a telescope.  Jupiter, being dimmer, wasn't quite visible yet.  If a person with a telescope and a high magnification (therefore a small field of view) started on Venus, there was a small window of time for which he or she could move the telescope left and right; such would mean moving quickly from one planet to another without adjusting the telescope in altitude--just azimuth.  As I mentioned early in this series of journals, an altitude/azimuth (alt/az) scope is a good starter-telescope, and the most basic of telescopes are made this way: pivoting on a mount, in two different directions.  As a reminder of some of the most basic Dobsonian telescopes, see this link: http://en.wikipedia.org/wiki/Dobsonian_telescope
Some shown are very basic and not too expensive, while others motor controlled for tracking and therefore, much more costly.  If you are thinking of buying a telescope for a first time, see if that site works! 
As shown in this zoom-out, the planets at the same altitude of 21º 48.784'.

*click on images to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp.