Why we add "the" before Moon, Sun and Earth, but don't add it before Mar?

[jiangyueming]

Why we add "the" before Moon, Sun and Earth, but don't add it before Mar?

Thank you.

[5jj]

'Mars' is the name of the planet.

[emsr2d2]

Why we add "the" before Moon, Sun and Earth, but don't add it before Mar?

Thank you.

I agree (mostly) with 5jj but I would make an argument for "Earth" being the name of our planet too. When we list them in order, we generally say "Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto" (yes, before anyone points it out I know poor old Pluto was stripped of its planetary status but I'm an old-fashioned girl!). We don't say "... Venus, the Earth, Mars ..."

You can see Venus from the moon.
You can see everything from the sun.
You can see a lot from Earth (no "the").

In addition, since I'm feeling picky this morning, neither our sun nor our moon is a planet.

[5jj]

I agree (mostly) with 5jj but I would make an argument for "Earth" being the name of our planet too.

I agree. When we use it as the name, we don't use an article. The word can also be used with a meaning similar to 'that planet on which we live'; With the idea of 'planet' in mind, the article can be used.