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!
July 2024: What Planet is Next to 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!
Planetary Opposition 2024: Jupiter, Saturn, and Other Planets At Their Brightest
The best time to view most planets is at the astronomical opposition. Find out what it means and when to see the upcoming oppositions.
Planet Uranus: The Coldest Planet
Uranus has a peculiar chemical composition, extreme temperatures, and the most unusual axial tilt. Here we’ll take a closer look at this planet.
Mars: Facts About the Red Planet
Why is Mars red? What’s the gravity on Mars? Read this article to get answers to these and many other questions and learn more about the Red Planet.
Facts About Mercury: All You Need to Know
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!
Planetary Conjunctions: What Are They and When Is the Next One?
Stay up to date with our complete list of planetary conjunctions! Mark your calendars, and be sure to observe these fascinating astronomical phenomena.
Cruithne: Earth’s Second Moon?
Does the Earth have a second Moon? Here you can learn everything about asteroid Cruithne that made us wonder.
Planet Neptune: Explore the Farthest Planet From the Sun!
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.
Jupiter Facts: The Biggest Planet in the Solar System
The bright Jupiter is known for its many moons, unstable surface, and mysterious Great Red Spot. Is there something else? Find out!
Facts About Venus: Explore the Earth's Sister Planet
Why is Venus so hot and bright? When is the best time to observe it? Read this article to get answers to these and many other questions about this planet.