Login | Sign Up | Print Page
Enchanted Learning Logo Enchanted Learning Logo
Home Site Index What's New Free Sample Pages Login Subscribe
Follow us on Twitter Like us on Facebook
Advertisement.

EnchantedLearning.com is a user-supported site.

Site members have full access to an ad-free, print-friendly version of the site.

Click here to learn more.

title image

The Planets (plus the Dwarf Planet Pluto)

AstronomyPlanetsScience
Astronomy Table of Contents►
Astronomy Site Index►
Share this page:
Mercury Mercury Venus Venus Earth Earth Mars Mars Jupiter Jupiter Saturn Saturn Uranus Uranus Neptune Neptune Pluto Pluto
Mercury Venus Earth
Mars Jupiter Saturn
Uranus Neptune Pluto

Our Solar System Our solar system consists of the sun, eight planets, moons, many dwarf planets (or plutoids), an asteroid belt, comets, meteors, and others. The sun is the center of our solar system; the planets, their moons, a belt of asteroids, comets, and other rocks and gas orbit the sun.

The eight planets that orbit the sun are (in order from the sun): Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune. Another large body is Pluto, now classified as a dwarf planet or plutoid. A belt of asteroids (minor planets made of rock and metal) lies between Mars and Jupiter. These objects all orbit the sun in roughly circular orbits that lie in the same plane, the ecliptic (Pluto is an exception; it has an elliptical orbit tilted over 17° from the ecliptic).

Easy ways to remember the order of the planets (plus Pluto) are the mnemonics: “My Very Excellent Mother Just Sent Us Nine Pizzas” and “My Very Easy Method Just Simplifies Us Naming Planets” The first letter of each of these words represents a planet - in the correct order.

Relative planet sizes

The largest planet is Jupiter. It is followed by Saturn, Uranus, Neptune, Earth, Venus, Mars, Mercury, and finally, tiny Pluto (the largest of the dwarf planets). Jupiter is so big that all the other planets could fit inside it.

The Inner Planets vs. the Outer Planets

The inner planets (those planets that orbit close to the sun) are quite different from the outer planets (those planets that orbit far from the sun).

  • The inner planets are: Mercury, Venus, Earth, and Mars. They are relatively small, composed mostly of rock, and have few or no moons.
  • The outer planets include: Jupiter, Saturn, Uranus, Neptune, and Pluto (a dwarf planet). They are mostly huge, mostly gaseous, ringed, and have many moons (again, the exception is Pluto, the dwarf planet, which is small, rocky, and has four moons).

Temperatures on the Planets

Planet temperature chart Generally, the farther from the Sun, the cooler the planet. Differences occur when the greenhouse effect warms a planet (like Venus) surrounded by a thick atmosphere.

Density of the Planets

Planet density chart The outer, gaseous planets are much less dense than the inner, rocky planets.

The Earth is the densest planet. Saturn is the least dense planet; it would float on water.

The Mass of the Planets

Planet mass chart Jupiter is by far the most massive planet; Saturn trails it. Uranus, Neptune, Earth, Venus, Mars, and Pluto are orders of magnitude less massive.

Gravitational Forces on the Planets

Planet gravity chart The planet with the strongest gravitational attraction at its surface is Jupiter. Although Saturn, Uranus, and Neptune are also very massive planets, their gravitational forces are about the same as Earth. This is because the gravitational force a planet exerts upon an object at the planet’s surface is proportional to its mass and to the inverse of the planet’s radius squared.

A Day on Each of the Planets

Planet day length chart A day is the length of time that it takes a planet to rotate on its axis (360°). A day on Earth takes almost 24 hours.

The planet with the longest day is Venus; a day on Venus takes 243 Earth days. (A day on Venus is longer than its year; a year on Venus takes only 224.7 Earth days).

The planet with the shortest day is Jupiter; a day on Jupiter only takes 9.8 Earth hours! When you observe Jupiter from Earth, you can see some of its features change.

The Average Orbital Speed of the Planets

Planet orbital speed chart As the planets orbit the Sun, they travel at different speeds. Each planet speeds up when it is nearer the Sun and travels more slowly when it is far from the Sun (this is Kepler’s Second Law of Planetary Motion).

The Planets in Our Solar System

Planet (or Dwarf Planet) Distance from the Sun
(Astronomical Units/miles/km)
Period of Revolution Around the Sun
(1 planetary year)
Period of Rotation
(1 planetary day)
Mass
(kg)
Diameter
(miles/km)
Apparent size from Earth Temperature
(Kelvin)
Number of Moons
Mercury 0.39 AU
36 million miles
57.9 million km
87.96
Earth days
58.7
Earth days
3.3 x 1023 3,031 mi
4,878 km
5-13
arc seconds
100-700 K
mean: 452 K
0
Venus 0.723 AU
67.2 million mi
108.2 million km
224.68
Earth days
243
Earth days
4.87 x 1024 7,521 mi
12,104 km
10-64
arc seconds
726 K 0
Earth 1 AU
93 million mi
149.6 million km
365.26
days
24
hours
5.98 x 1024 7,926 mi
12,756 km
N/A 260-310 K 1
Mars 1.524 AU
141.6 million mi
227.9 million km
686.98
Earth days
24.6
Earth hours
(1.026 Earth days)
6.42 x 1023 4,222 miles
6,787 km
4-25
arc seconds
150-310 K 2
Jupiter 5.203 AU
483.6 million mi
778.3 million km
11.862
Earth years
9.84
Earth hours
1.90 x 1027 88,729 mi
142,796 km
31-48
arc seconds
120 K
(cloud tops)
67
(18 named plus many smaller ones)
Saturn 9.539 AU
886.7 million mi
1,427.0 million km
29.456
Earth years
10.2
Earth hours
5.69 x 1026 74,600 mi
120,660 km
15-21
arc seconds
(excluding rings)
88 K 62
(30 unnamed)
Uranus 19.18 AU
1,784.0 million mi
2,871.0 million km
84.07
Earth years
17.9
Earth hours
8.68 x 1025 32,600 mi
51,118 km
3-4
arc seconds
59 K 27
(6 unnamed)
Neptune 30.06 AU
2,794.4 million mi
4,497.1 million km
164.81
Earth years
19.
Earth hours
1.02 x 1026 30,200 mi
48,600 km
2.5
arc seconds
48 K 13
Pluto
(a dwarf planet)
39.53 AU
3,674.5 million mi
5,913 million km
247.7
years
6.39
Earth days
1.29 x 1022 1,413 mi
2,274 km
0.04
arc seconds
37 K 4

Another Planet?

In 2005, a large object beyond Pluto was observed in the Kuiper belt.

A few astronomers think that there might be another planet or companion star orbiting the Sun far beyond the orbit of Pluto. This distant planet/companion star may or may not exist. The hypothesized origin of this hypothetical object is that a celestial object, perhaps a hard-to-detect cool, brown dwarf star (called Nemesis), was captured by the Sun’s gravitational field. This planet is hypothesized to exist because of the unexplained clumping of some long-period comet’s orbits. The orbits of these far-reaching comets seem to be affected by the gravitational pull of a distant, Sun-orbiting object.

Planet Activities and Quizzes

  • Planet Coloring pages
  • An interactive puzzle on the Solar System.
  • Find It!, a quiz on the planets.
  • A fill-in-the-blank (cloze) activity on the Solar System - or go to the answers.
  • Solar System Model to make.
  • Solar System calendar to print out and color.
  • Solar System Crafts
  • How to write a report on a planet - plus a rubric.
Astronomy and Space K-3 Theme Page
Astronomy and Space K-3 Theme Page

Astronomy and Space

The Planets of our Solar System Book
The Planets of our Solar System Book

A short, printable activity book on the planets of the Solar System for fluent readers.

Solar System Book, A Printable Book
Solar System Book, A Printable Book

Solar System Book, A Printable Book. Print out a Solar System early reader book.

Solar System Coloring Pages
Solar System Coloring Pages

Solar System Coloring Pages.

Label Solar System Diagram Printout
Label Solar System Diagram Printout

Label Solar System Diagram Printout.

Label the Earth's Atmosphere Printout
Label the Earth's Atmosphere Printout

Label the Earth’s atmosphere in this printable worksheet.

Label Earth's Layers Printout
Label Earth's Layers Printout

Read the definitions then label the layers of the Earth in this printable worksheet.

Celsius Bar Graph Questions Worksheet #2
Celsius Bar Graph Questions Worksheet #2

Celsius Bar Graph Questions Worksheet #2 Page to Print Worksheet. Use the bar graph of the average temperatures of the planets to answer questions.

Label Moon Phases Diagram Printout
Label Moon Phases Diagram Printout

Label Moon Phases Diagram Printout.

Label the Lunar Eclipse Printout
Label the Lunar Eclipse Printout

Label the Lunar Eclipse Printout.

Label the Aphelion-Perihelion Printout
Label the Aphelion-Perihelion Printout

Label the aphelion (farthest point in orbit) and perihelion (closest point in orbit) of a planet in orbit.

10 Planet Words Alphabetical Order Worksheet Printout
10 Planet Words Alphabetical Order Worksheet Printout

10 Planet Words Alphabetical Order Worksheet Printout.

Label Solar System Diagram Printout
Label Solar System Diagram Printout

Label Solar System Diagram Printout.

Label the Planets (les Planètes) in French
Label the Planets (les Planètes) in French

In this printable worksheet, label the planets (les Planètes) in French using the word bank.

Label the Planets in German
Label the Planets in German

In this printable worksheet, use the word bank to label the planets (planeten) in German.

Label the Planets in Italian
Label the Planets in Italian

In this printable worksheet, use the word bank to label the planets (i pianeti) in Italian.

Label the Planets in Portuguese
Label the Planets in Portuguese

In this printable worksheet, use the word bank to label the planets (os planetas) in Portuguese.

Label the Planets (los Planetas) in Spanish
Label the Planets (los Planetas) in Spanish

In this printable worksheet, use the word bank to label the planets (los planetas) in Spanish.

Other Links:
Estimated Grade Level
Our subscribers' grade-level estimate for this page:
2nd - 4th
You Might Also Like:
Length of a Day and Year on Mercury
Map of Mercury
Planets Quiz
Uranus
Mercury Quiz
The Planets
Mercury
Venus
Earth
Mars
Jupiter
Saturn
Uranus
Neptune
(Pluto - dwarf planet)
Your weight on the planets
Your age on the planets
The Solar System
— Our Solar System —
The Sun
The Planets
The Moon
Asteroids
Kuiper Belt
Comets
Meteors
Zoom Astronomy
— All About Astronomy —
Table of Contents
Index
More on Astronomy
Stars
Our Solar System
Astronomy Glossary
Hall of Astronomers
Printables, Worksheets, and Activities
Advertisement.
▾ See more
Site Overview
What's New
Enchanted Learning Home
Monthly Activity Calendar
Books to Print
Site Index
Enchanted Blog
K-3
Crafts
K-3 Themes
Little Explorers
Picture Dictionary
PreK/K Activities
Rebus Rhymes
Stories
Writing
Cloze Activities
Essay Topics
Newspaper
Writing Activities
Parts of Speech
Fiction
The Test of Time
Biology
Animal Printouts
Biology Label Printouts
Biomes
Birds
Butterflies
Dinosaurs
Biology Continued
Food Chain
Human Anatomy
Mammals
Plants
Rainforests
Sharks
Whales
Physical Sciences: K-12
Astronomy
The Earth
Geology
Hurricanes
Landforms
Oceans
Tsunami
Volcano
Languages
Dutch
French
German
Italian
Japanese (Romaji)
Portuguese
Spanish
Swedish
Geography/History
Explorers
Flags
Geography
Inventors
US History
Other Topics
Arts and Artists
Calendars
College Finder
Crafts
Graphic Organizers
Label Me! Printouts
Math
Music
Word Wheels
Copyright © 1998-2023 EnchantedLearning.com
How to cite a web page
-
Our Privacy Policy
-
Site Index
-
Contact Us
-
About Us
-
Subscribe
Advertisement.
Advertisement.