His reasoning was astrological: the great planetary conjunction of that year had transformed the world of learning; certainly it had led to a flood of astrological publications.

From this, he noted that planetary conjunctions and oppositions would never recur in quite exactly the same way.

There are also tables of future solar and lunar eclipses, planetary conjunctions and planet locations, all current to 2018.

Sky phenomena such as planetary conjunctions, solar eclipses, lunar eclipses, as well as atmospheric phenomena like haloes, rainbows, and noctilucent clouds, are all occurring in the shallow sky.