"This is impossible!"-Nute Gunray

If you're referring to Earth as in THE Earth, then yes, you do.

When calling the planet on which we live by its name, you capitalize it (Earth). It is a proper noun, since you are referring to the certain celestial body Earth by its given name. In the same way, we capitalize Venus, Mars, Neptune, etc. Sometimes when people say "the earth," they don't capitalize it as they're basically just using the word earth in place of world. But when you specifically refer to Earth by name, it's capitalized. Kinda like how you might say "the book" when vaguely referring to a book sitting on a table somewhere, but if you were talking more specifically about that particular book you might say "The Hobbit" or whatever and capitalize it.