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!

Planet closest to the Moon in the sky: March 8-11

March 2024: What Planet is Next to the Moon Tonight?

~8 min
Astronomical News

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!

Venus and Saturn in March 2024

Planetary Conjunctions: What Are They and When Is the Next One?

~6 min
Astronomical News

Stay up to date with our complete list of planetary conjunctions! Mark your calendars, and be sure to observe these fascinating astronomical phenomena.

Mars and its two moons, Phobos and Deimos

Mars: Facts About the Red Planet

~10 min
Astronomical News

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.

Planet Pictures

Planet Pictures: Then vs Now


From grainy black-and-white to breathtaking high-res images! 🪐Explore the journey of planetary photography through our infographics, showing the oldest and newest photos of planets side by side.

Facts About Uranus

Planet Uranus: The Coldest Planet

~10 min
Astronomical News

Uranus has a peculiar chemical composition, extreme temperatures, and the most unusual axial tilt. Here we’ll take a closer look at this planet.

Space Object or Something Else?

Space Object or Something Else?


A weirdly-shaped asteroid or a potato? A high-resolution image of a star or just a piece of sausage? In this quiz, you'll need to guess whether the pictures represent celestial objects or something completely different.

Neptune at opposition 2021

Planet Neptune: Explore the Farthest Planet From the Sun!

~9 min
Astronomical News

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.

Amazing Planet Venus

Facts About Venus: Explore the Earth's Sister Planet

~8 min
Astronomical News

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.

Pluto guide

Facts About Pluto: Explore The Peculiar Dwarf Planet

~8 min
Astronomical News

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!

Facts About Mercury

Facts About Mercury: All You Need to Know

~7 min
Astronomical News

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!