"Big blue marbles" is a phrase that refers to the Earth. There are many synonyms for this phrase, including: the globe, the world, the planet, the orb, the celestial sphere, the terraqueous globe, the blue planet, the third planet from the sun, and the pale blue dot. These terms all convey the idea of a large, round object that is primarily blue in color and is home to all living beings. Whether spoken by astronauts orbiting above or by everyday people on the ground, these synonyms are an excellent way to describe our remarkable planet and the life it sustains.