Mountain closest to space

When measuring mountains by their distance from the centre of the Earth, rather than their height above sea level, the mountain closest to space is Mount Chimborazo in Ecuador. Although Mount Everest is the highest mountain above sea level, Chimborazo’s summit is actually the farthest point from the Earth’s centre and thus the closest point on Earth to outer space.

Understanding the Concept

The Earth is not a perfect sphere; it is an oblate spheroid, meaning it bulges slightly at the equator and flattens at the poles. Because of this equatorial bulge, the Earth’s radius at the equator is about 21 kilometres (13 miles) greater than at the poles.
As a result, mountains located near the equator begin their height measurements from a point that is already farther from the centre of the Earth compared to those at higher latitudes. Therefore, even if a mountain is shorter in elevation above sea level, its summit can still be farther from the planet’s centre — effectively closer to space.

Mount Chimborazo, Ecuador

• Location: Cordillera Occidental, Andes Mountains, Ecuador (just one degree south of the Equator).
• Elevation above sea level: Approximately 6,263 metres (20,549 feet).
• Distance from Earth’s centre: About 6,384.4 kilometres (3,967.1 miles).

By comparison:

• Mount Everest’s summit is about 8,848.86 metres (29,031.7 feet) above sea level, but because it lies near the Tropic of Cancer, its distance from Earth’s centre is around 6,382.3 kilometres (3,965.8 miles).

This means Chimborazo’s peak extends about 2.1 kilometres (1.3 miles) farther into space than Everest’s, despite being about 2,600 metres lower in elevation above sea level.

Reasons for Chimborazo’s Distinction

1. Equatorial Bulge: The Earth’s equatorial radius is greater due to centrifugal force from its rotation, pushing the equator outward.
2. Geographic Position: Chimborazo’s location almost exactly on the equator gives it a “head start” in distance from the Earth’s centre.
3. Measurement Basis:
   • Everest: Tallest when measured above mean sea level.
   • Chimborazo: Farthest when measured from Earth’s centre.

Thus, while Everest is the “highest” mountain in terms of elevation, Chimborazo is the point on Earth’s surface that reaches farthest into space.

Other Notable Comparisons

• Mount Kilimanjaro (Tanzania): Located close to the equator (5,895 m above sea level), it is also among the highest points farthest from Earth’s centre, though still below Chimborazo.
• Huascarán (Peru): Another Andean peak (6,768 m above sea level) lies relatively close to the equator, making it one of the next farthest points from the centre after Chimborazo.
• Mount Everest (Nepal/Tibet): Despite being the world’s tallest above sea level, its position at 28° N latitude reduces its geocentric distance compared with Chimborazo.