English: This photo is of a wall mural that is a scale diagram of the inner Solar System showing the distance involved in a space mission going from Earth to Mars. The boy is pointing at Mars as the destination, with Earth at the left side of the image as the starting point. Earth orbited by the Moon is drawn to scale (also inset for clarity). This radius out to the Moon is the furthest that humans have ever traveled. So this display gives an accurate appreciation for how the distance involved for a human mission to Mars is orders of magnitude farther than what was accomplished in the Project Apollo landings on the Moon.

The frame on the bottom-left shows the overview of the entire inner Solar System, including the orbits of Mars, Earth, Venus and Mercury around the Sun. The straight black line from the Earth through the Sun and out to Mars is what is represented down the corridor. The trajectory from Earth to Mars follows a Hohmann transfer ellipse around the Sun. The panels along the black line, from left to right, are Earth, Venus, Mercury, the Sun, Mercury again, Venus again, Earth again, and finally Mars (being pointed to).

This photo was taken in Building 16 at NASA's Johnson Space Center in Houston. Standing next to the boy is an aerospace engineer working at NASA JSC.