Earth (capitalization)

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When the noun earth refers to our planet, it is capitalized only when it’s a proper noun (meaning it acts like a name and is not preceded by the—for example, everything on Earth). The word is not capitalized when it is a common noun (meaning it does not act like a name and is preceded by the—e.g., everything on the earth).

And of course, earth is sometimes used to mean the soft part of land (synonymous with dirt or soil), in which case it does not need to be capitalized. It can also mean the land surface of the world or the realm of mortal existence without becoming a proper noun.


Earth is often unnecessarily capitalized, but most major publications follow the convention we’ve outlined. For example, Earth is correctly capitalized in these sentences because it is essentially a name (and hence is not preceded by the):

[S]cientists in Europe have for the first time recorded what may be one of the loudest animals on Earth for its size. [USA Today]

This means its light has taken an astonishing 12.9 billion years to reach us here on Earth. [BBC News]

An asteroid the size of a tour bus streaked harmlessly past Earth, passing within 12,230km. [The Southland Times]

And in the following examples, earth is correctly uncapitalized because it’s treated as a common noun (with the article the):

Shale gas is extracted from beneath the surface of the earth through a process called hydraulic fracturing, or “fracking.” [CBC]

Greenhouse gas emissions in volume affect the earth’s climate. [Financial Times]

Because of science, we were able to grasp the age of the earth. [Boston Globe]

19 thoughts on “Earth (capitalization)”

  1. I think that this rule should be revised so that “Earth” would apply in contexts referring to our planet, its specific properties as a whole, or general planetary properties that are specifically relevant to our species, while “earth” would apply in contexts that are local with respect to our planet’s surface or may be properties of Earth-like planets in general according to current scientific theories.

    This would create greater consistency between our language and the recent scientific discoveries that thousands of planets exist orbiting other stars, the measurable properties of which suggest that each of the newly discovered planets is unique.

    • Our scientific knowledge is rapidly approaching the point at which reasonable statistical estimates of planetary vs. stellar numbers can be performed. Preliminary studies suggest that planetary formation is a byproduct of stellar formation, indicating that planets may be common throughout our Universe.

      • I agree with all of the given examples of Earth.

        I disagree with all of the given examples of earth.

        1. “Shale gas….”
        This is an industrial activity specific to our species. While shale gas may be present on other planets, we currently have no scientific evidence that any other life form exists which is capable of using the technique.

  2. The idea that “the” does not precede a proper noun seems flawed (the Brooklyn Bridge, the Arctic, etc.) There is no difference in this respect to an astronaut saying “look at Earth down there” or “look at the earth down there.” I’m just sayin’.

  3. I also think the rule should be revised. Earth should be capitalized whenever it is used to speak specifically of our planet, regardless whether a “the” precedes it. In fact, especially when a “the” precedes it! Earth should not be capitalized when referring generally to ground, dirt, soil, etc. IMHO.

  4. Originally, in English, all nouns were capitalized, whether they were ordinary nouns or proper nouns. This rule is still followed in German writing today. Creating artificial distinctions as here with the word “Earth”, vs. “the earth” is nonsensical and does not follow historic usage. The opinion expressed by Grammarist (or is it “the grammarist”?) amounts to unwelcome revisionism.

  5. What does the rule say if we write “this Earth/earth”? Because “this” can be a pronoun as well as an adjective, whereas “the” is an article, it would seemingly be correct to write “this Earth.” Correct or not?

  6. “…the surface of the earth…” isn’t that using it as a name? What is “the earth” if not the name of our planet? No one ever said you can’t use “the” with proper nouns, so I’m calling nonsense on this rule.

  7. C’mon! Earth is the name of the planet, whether “the” is used before it or not: “The satellite fell from the sky and landed on the Earth.” Lower case earth is dirt. BUT would we say “The satellite fell and landed on THE Mars?” Nope. So maybe there’s a new(er) use for lower-case earth…

  8. I disagree, however, with the use of “earth” as a common noun when referring to the planet as a whole. In the examples listed for the uncapitalized version, my read on it is that it’s still being referred to in the context of the planet itself, which would make it a proper noun, and therefor capitalized. The lower case earth, in my mind, refers to essentially dirt and similar parts of the surface. The rest is descriptive of the planet itself. So we SHOULD say, “Greenhouse gas emissions in volume affect the Earth’s climate.” The earth, as in dirt, doesn’t have climate, and therefore can’t be affected by greenhouse gases, per se. The Earth, as a planet, does have a climate and could therefore be affected by greenhouse gases.

  9. One of the ways the convention of “the earth” arose is a combination of habit and the realities of sentence processing as a way of producing speech and writing. That’s how some irregularities come about.

    Other examples of this kind of irregularities are these two:

    I closed the door. I jumped onto the table. I grabbed the rope. I pulled the handled. But then there is the irregular “put.” I put the cup away. I put my luggage into the closet. Why not “I putted the cup away.” “I putted my luggage into the closet”? Habit and sentence processing.

    Same with the indefinite article preceeding the word “historic.”

    Every knows that we say “a happy little girl,” “a high fence.” And we say “an elusive little girl,” and “an old fence.”

    But we often say “an historic occasion.” Why?

    The rule is “a” before a word beginning with a consonant sound, “an” before a word beginning with a vowel sound. It isn’t spelling. We say “a phone.” “ph” is pronounced as a consonant.”

    But “an historic” is a phrase spoken in Massachusetts and in the UK when and where “historic” was pronounced “istoric.” So an irregular use of “an” developed.”

    Lowercase “earth” is like that. An anachronism to times when Earth was somehow not thought of in the same category as other planets in this and other solar systems.

    So I say “a historic” and “Earth” except for soil or dirt. Period. Such usage just corrects errors of history.

    This attitude could yield a historic trend on Earth if others did it a lot. I putted a lot of thought into this post, by the way.


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