Planetary Conjunctions:

The following were calculated with various incarnations of my conjunction program.

These are geocentric conjunctions (run on a UNIX system in 2003).

These are geocentric conjunctions in celestial longitude (VAX version run around 1994).

These are three-planet conjunctions when the planets fit in the smallest circle.

Additional information on these calculations is found in "Mutual Occultations of Planets: 1557-2230", Sky and Telescope, March 1979.

There was a remarkable coincidence that the printed version of the Sky and Telescope article appeared on the same page as an article about Galileo and his lunar drawings. My article also suggested examination of historical observations to see if Uranus or Neptune could have been mistaken for a moon of Jupiter and thus being seen before it was discovered. Stillman Drake followed up on that notion using Galileo's observations from 1613. It turns out that Neptune actually shows up as a moving "star" on Galileo's drawings so Galileo himself unwittingly observed Neptune right around the time of the invention of the telescope. This was published in Scientific American in 1980. My role in this was recognized in receiving the R.R. Newton award by the International Journal of the Scientific History in 2009.

Some additional occultations were found by Larry Bogan on his website.

Planetary Phenomena:

Here are some planetary phenomena for the present decade.