Everything we can reach sits within about 12 km of sea level, under half a percent of this 6,779 km trip. So each landmark gets one beat of scroll, and the counter glides between them on a logarithmic curve. The gauge on the right is the same trip at true scale.
1 · Rank scale. Every landmark gets the same slice of scroll, however far apart they really are.
2 · Smooth counter. Between beats the counter follows asinh(height ÷ 300 m): linear near sea level, logarithmic far away, so it crosses zero without a jump.
3 · True gauge. The bar on the right plots real proportions: the crust is a hairline, and the first 20 landmarks are squeezed into the top 8%.
4 · Honest ruler. The readout below says what one screen of scroll is worth right now.
Temperature, pressure and gravity come from the US Standard Atmosphere and a PREM-like Earth model; deep values are approximate.