Ask the ChatbotGames & QuizzesHistory & SocietyScience & TechBiographiesAnimals & NatureGeography & TravelArts & CultureProConMoneyVideos
planet
Table of Contents
References & Edit History Related Topics
Images & Videos
solar system to scale
Why isn't Pluto a planet?
Learn about the dwarf planets within our solar system
Explore exoplanets and the techniques used to detect them
effects of gravity on the Moon and Earth
Know the ten interesting facts that prove the earth is round
For Students
planet summary
Quizzes
Model of a molecule. Atom, Biology, Molecular Structure, Science, Science and Technology. Homepage 2010 arts and entertainment, history and society
Science Quiz
The orbits of the planets and other elements of the solar system, including asteroids, Kuiper belt, Oort cloud, comet
Space Odyssey
Saturn. Saturn and its rings. Second largest planet of the solar system. Space Art
Planets and the Earth’s Moon
1 July 2002: The Solar and Heliospheric Observatory (SOHO) satellite reveals a massive solar eruption more than 30 times the Earth's diameter. The eruption formed when a loop of a magnetic field over the surface of the Sun trapped hot gas.
Brightest Star in the Solar System
Nicolaus Copernicus. Nicolas Copernicus (1473-1543) Polish astronomer. In 1543 he published, forward proof of a Heliocentric (sun centered) universe. Coloured stipple engraving published London 1802. De revolutionibus orbium coelestium libri vi.
All About Astronomy
Related Questions
Read Next
Background: abstract bubble planets with clouds. astrology, astronomy, atomosphere, big bang, bubbles, fantasy, future, galaxy, universe, stars
9 Ghostly Planets
Solar system illustration. (planets; sun)
Why Are Planets Round?
Remarkable new details of Pluto's largest moon Charon are revealed in this image from New Horizons' Long Range Reconnaissance Imager (LORRI), taken late on July 13, 2015 from a distance of 289,000 miles
Why Is Pluto No Longer a Planet?
This close-up image of a dust storm on Mars was acquired by the Mars Color Imager instrument on NASA Mars Reconnaissance Orbiter on Nov. 7, 2007. This image is centered on Utopia Planitia
Do Hurricanes Happen on Other Planets?
Solar System with the sun and planets amid stars. Illustration Venus Mercury Earth Mars Jupiter Saturn Neptune Uranus space orbit
Understanding Kepler’s Laws of Planetary Motion
Discover
Duel between Aaron Burr and Alexander Hamilton, illustration after a painting by J. Mund.
10 Famous Duels
General Pershing's troops moving into Mexico in 1917 during World War I.
Timeline of World War I
Aphrodite. Greek mythology. Sculpture. Aphrodite is the Greek goddess of love and beauty.
12 Greek Gods and Goddesses
Los Angeles Police Department wanted flyer on Elizabeth Short, aka the "Black Dahlia," who was brutally murdered in January 1947. The FBI supported the Los Angeles Police Department in the case, including by identifying Short through her fingerprints that
America’s 5 Most Notorious Cold Cases (Including One You May Have Thought Was Already Solved)
British troops in a trench on the Western front during World War I. One officer takes reports of the fighting over a field telephone while the officer on the left jots it down and issues new orders.
Life in the Trenches: A World War I Photo Gallery
Berlin, 1936 - Jesse Owens of the USA in action in the mens 200m at the Summer Olympic Games. Owens won a total of four gold medals.
Was Jesse Owens Snubbed by Adolf Hitler at the Berlin Olympics?
Queen Elizabeth II addresses at opening of Parliament. (Date unknown on photo, but may be 1958, the first time the opening of Parliament was filmed.)
All 119 References in “We Didn’t Start the Fire,” Explained

planet: Related Content

Written and fact-checked by
The Information Architects of Encyclopaedia Britannica

The Information Architects maintain a master list of the topics included in the corpus of  Encyclopædia Britannica, and create and manage the relationships between them.
The Information Architects of Encyclopaedia Britannica

News •

Astronomers discover 128 new moons orbiting Saturn • Mar. 12, 2025, 7:04 AM ET (The Guardian)
'Planet parade' photo captures 7 planets in a line over Earth — possibly for the 1st time ever • Mar. 1, 2025, 2:20 AM ET (Live Science)
'Planetary parade': Seven worlds to be visible this week • Feb. 24, 2025, 11:18 PM ET (BBC)

Photos and Videos

solar system to scale
effects of gravity on the Moon and Earth
Why isn't Pluto a planet?
Learn about the dwarf planets within our solar system
Explore exoplanets and the techniques used to detect them
Know the ten interesting facts that prove the earth is round
See All Videos and Images →

Related Topics and References

Topics
Dig Deeper: More Articles That Discuss This Topic

Key People

Understanding Newton's theory of universal gravitation
Isaac Newton
English physicist and mathematician
Johannes Kepler
Johannes Kepler
German astronomer
Galileo
Galileo
Italian philosopher, astronomer and mathematician
Didier Queloz
Swiss astronomer
Michel Mayor
Swiss astronomer
Eudoxus of Cnidus
Greek mathematician and astronomer
Apollonius of Perga
Greek mathematician
Geoffrey Marcy
American astronomer
illustration of Robert Hooke's law of elasticity of materials
Robert Hooke
British scientist
Gerard Peter Kuiper
American astronomer
Boscovich, detail of a portrait by an unknown artist; in Dubrovnik Cloister, Croatia
Ruggero Giuseppe Boscovich
Italian astronomer and mathematician
Peter Andreas Hansen, detail from a lithograph by Rudolf Hoffmann, 1856
Peter Andreas Hansen
German astronomer
George William Hill
American astronomer
William Rutter Dawes
British astronomer
Jérôme Lalande, etching by Christian Fritzsch, 1773.
Jérôme Lalande
French astronomer

Related Quizzes and Features

Quiz
Model of a molecule. Atom, Biology, Molecular Structure, Science, Science and Technology. Homepage 2010 arts and entertainment, history and society
Science Quiz
This artist's concept illustrates Kepler-16b, the first planet known to definitively orbit two stars -- what's called a circumbinary planet. The planet, which can be seen in the foreground, was discovered by NASA's Kepler mission. The two orbiting stars r
Extrasolar Planets
The orbits of the planets and other elements of the solar system, including asteroids, Kuiper belt, Oort cloud, comet
Space Odyssey
Encyclopaedia Britannica thistle graphic to be used with a Mendel/Consumer quiz in place of a photograph.
27 True-or-False Questions from Britannica’s Most Difficult Science Quizzes
Nicolaus Copernicus. Nicolas Copernicus (1473-1543) Polish astronomer. In 1543 he published, forward proof of a Heliocentric (sun centered) universe. Coloured stipple engraving published London 1802. De revolutionibus orbium coelestium libri vi.
All About Astronomy
1 July 2002: The Solar and Heliospheric Observatory (SOHO) satellite reveals a massive solar eruption more than 30 times the Earth's diameter. The eruption formed when a loop of a magnetic field over the surface of the Sun trapped hot gas.
Brightest Star in the Solar System
Nicolaus Copernicus. Nicolas Copernicus (1473-1543) Polish astronomer. In 1543 he published, forward proof of a Heliocentric (sun centered) universe. Coloured stipple engraving published London 1802. De revolutionibus orbium coelestium libri vi.
All About Astronomy
Planet Neptune
Giants of Our Solar System
Ultraviolet image of Venus' clouds as seen by the Pioneer Venus orbiter; February 26, 1979.
Venus
Saturn. Saturn and its rings. Second largest planet of the solar system. Space Art
Planets and the Earth’s Moon
Nicolaus Copernicus. Nicolas Copernicus (1473-1543) Polish astronomer. In 1543 he published, forward proof of a Heliocentric (sun centered) universe. Coloured stipple engraving published London 1802. De revolutionibus orbium coelestium libri vi.
All About Astronomy
Demystified
Remarkable new details of Pluto's largest moon Charon are revealed in this image from New Horizons' Long Range Reconnaissance Imager (LORRI), taken late on July 13, 2015 from a distance of 289,000 miles
Why Is Pluto No Longer a Planet?
Solar system illustration. (planets; sun)
Why Are Planets Round?