Planets & Moons
There are 8 officially recognized Solar System planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Most of them, except Mercury and Venus, have their own natural satellites, commonly called “moons.” Some of the dwarf planets, like Pluto and Eris, have moons, too. Here, you’ll learn the best dates to observe planets in the sky and find everything you need to know about planets, dwarf planets, and natural satellites. When you learn enough, test your astronomy skills with our challenging quizzes!
Retrograde motion explained: what is retrograde motion in astronomy
Discover the science of retrograde planets! Understand the mechanics of retrograde motion, its causes, and its significance in the study of astronomy and planetary behavior.
Bright “Star” Next to Moon: What Planet Is Near the Moon Tonight?
What is that bright dot shining near the Moon tonight? Find out about stars and planets that can be seen next to our natural satellite this month!
How to See the Planets Tonight: Tips For Beginners (No Telescope Needed)
Learn exactly where and when to spot Venus, Jupiter, Saturn & more tonight with our step-by-step guide. No equipment required — perfect for city-dwellers and beginners!
All About Pluto: Explore The Peculiar Dwarf Planet
How far is Pluto from the Earth? Why isn’t Pluto a planet? Read this article to get answers to these and many other questions!
Planetary Alignments Explained: Don’t Miss the 6-Planet Parade on August 10, 2025
The Large Planetary Alignment is coming! 6 planets will be visible in the mornings around August 10 — the Full Moon will complete the picture. Find out how to see the planets lining up in the sky.
Neptune: The Farthest & Windiest Planet in the Solar System
How big is Neptune? What is Neptune made of? Why is Neptune blue? Read our article and learn curious facts about the outermost planet in the Solar System.
Planetary Opposition 2025: Best Time to See Planets
The best time to view most planets is at the astronomical opposition. Find out what it means and when to see the upcoming oppositions.
Planetary Alignment Infographic: A Celestial Parade
Discover how to observe planetary alignments with this colorful infographic and mark your calendar for the next “planet parade”.
All About Mercury, The Smallest Planet In The Solar System
Explore the closest planet to the Sun! Find out how long a day on Mercury is and how many moons the planet has. Also, keep up with the upcoming Mercury events!
Venus Facts: Explore the Brightest Planet in The Sky
In July 2025, Venus is perfectly placed for observing and photography! Get to know the planet and learn about upcoming Venus events in this article.