Speaking of planetary alignments this great visual tool came to mind. It is called "Solar Scope" and shows the solar system for any point or period of time in full motion.

It's beautifully done and fun to run and play with.

The link is simple to remember:

Solar System Scope
http://www.solarsystemscope.com/

This screen grab shows August 15, 2015:

You can drag in the window to view from any angle, use the mouse wheel to zoom in and out, click the little play button at the bottom to set it all in motion.

Click the date at bottom center to pick any date to jump to. Even the rotation of the planets is simulated.

There is one control that took me some time to figure out and that is the SPEED of the motion. When you click the Play button at the bottom you get this little control panel:

The speed control is simply the slider control with the white dot. Drag to the right to increase speed (forward in time). Drag to the left to increase speed (backward in time).

Play around to discover more.

Double click a planet for more views. You can even add in the constellations in the background.

Whoever wrote this program was very very good. I love it.

A version with "enhanced graphics" is available for $9.99. Click the disk icon bottom left.