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Small BodiesStories, updates, insights, and original analysis from The Planetary Society.
What is a planetary conjunction?
An explainer on planetary conjunctions, and what it means when a planet is at conjunction or at opposition.
What does “Mercury in retrograde” actually mean?
"Mercury in retrograde" is one of the most searched terms relating to the planet. Astrological interpretations aside, apparent retrograde motion is an interesting phenomenon that has to do with orbital speeds and observer perspective.
Meet the snow worlds
Earth isn't the only planet with snow. From Io to Enceladus, here's where snow can be found in our solar system.