Last week I talked about the spectacular grouping of Venus, Jupiter and Mercury in the evening sky after sunset.

It continues.

Tonight I recommend that you find a clear horizon running from west to northwest and start viewing just before sunset so you can enjoy one of our famous Arizona sunsets and be ready for the planetary show thereafter. Be careful not to hurt your eyes by looking directly at the setting sun.

By 7:30 p.m., the planets should begin to show up in the darkening sky. Ever-brilliant Venus will be 10 degrees above the horizon. Just to its right (north) is Mercury. Above and a little left of Venus and Mercury is Jupiter. Don't take your time getting outside to see them, as they will effectively be gone from view by 8:10 p.m.

If you miss tonight's show, do not despair. It continues unabated for many more nights. Fast-moving Mercury will climb past Venus and then Jupiter to become the top of the trio by Monday night.

On Friday night, Venus and Mercury will only be 1.4 degrees apart as Mercury slides past Venus.

Venus is no sluggard and is also on the move, sliding past Jupiter on Monday and Tuesday nights when Venus and Jupiter will be only slightly more than one degree apart.

These close groupings of bright planets are known as conjunctions. Conjunctions are not common, and very close conjunctions such as these are rare.

Planetary conjunctions have no particular astronomical significance other than their beauty.

Even though Mercury, Venus and Jupiter appear very close to each other in the sky, they are still millions of miles apart but close enough for our enjoyment.

Moon Watch

The moon will be full Friday. It will appear nearly full as it rises tonight at 6. Sunset is at 7:20.

Contact Tim Hunter at