A Scale Model of the Universe:

Sun – a basketball in my hand (reduced in size by a factor of 5 × 10⁹, or 5 billion)

Earth – next door in the astronomy building (30 meters)

Pluto – in the campus observatory (1.2 kilometers)

Nearest star – Hawaii (8,000 kilometers)

Now, even smaller . . .

Sun – a marble in my hand (reduced in size by a factor of 5 × 10¹⁰, or 50 billion)

Earth – third row of the classroom (3 meters)

Pluto – filed under P in Zuhl library (120 meters)

Nearest star – Pueblo, Colorado (800 kilometers)

Center of Milky Way – 10 × beyond the Moon (6 million kilometers)

Nearest galaxy – Mars (400 million kilometers)