Supermoons and Minimoons: Learn what they are, and how to separate the hype (and there is a lot of that!) from the facts. Follow every full Moon through the year 2040, see if it will give an eclipse, and whether it is a supermoon, a minimoon, or neither.
Eclipses of the Moon: Find out about all the lunar eclipses from 1990 through 2060. See if they are visible in the US, when they occur during the night, how long they last, and how big the Moon will appear. How does your favorite lunar eclipse rate? Classify the color of the eclipse.
Libration of the Moon: Understand why the Moon wobbles, and plan observations so you can see a bit around the edges to parts that are not normally visible. See how libration relates to the shape of the Moon's orbit.
Venus/Jupiter Conjunctions: Venus and Jupiter are the two brightest naked-eye planets, and can make beautiful conjunctions in the sky. Find out when the best ones occur both at dawn and at dusk, through the year 2040.
Venus/Jupiter Series: The conjunctions between Venus and Jupiter occur in separate series, each one lasting about a human lifetime. At any given time, three such series are present. See which cycle belongs to you, your parents, your children, and grandchildren as we follow these cycles through the year 2060.
The Jupiter/Saturn 2020 Conjunction A guide to the Jupiter-Saturn conjunction of Dec 21, 2020, and a hint to the next good one on March 15 2080.
Conjunctions between Jupiter and Saturn occur on regular intervals of about 20 years.
It is easy to understand why, but looking in a bit more detail reveals that these conjunctions
occur in sets of six different series, with about 119 years separating conjunctions within
a series, each series cycling on a timescale of over 2000 years. A few of the
conjunctions are triplets visible in the middle of the night, while many others occur close to the Sun.
There are also regular features within a series, and cycles of the closest separations.
This page confronts all this complexity by analyzing the 150 or so conjunctions
that occur between 0 CE and 3000 CE.