Mount Everest is the highest point above sea level, but because the Earth bulges at the equator, the summit of a volcano in Ecuador sits farther from the centre of the planet, making it the closest piece of land on Earth to outer space.

Mount Everest is the highest point on Earth measured from sea level, at 8,848 metres. It is not the point on Earth’s surface that sits farthest from the centre of the planet. That distinction belongs to Chimborazo, a dormant volcano in the Ecuadorean Andes, whose summit reaches about 6,263 metres above sea level, roughly 2,600 metres lower than Everest.

The reason is the shape of the Earth. The planet is not a sphere. Its rotation makes it bulge at the equator, so a point at the equator sits farther from the centre than a point at the same sea-level altitude near a pole. Chimborazo lies about one degree south of the equator. Everest sits nearly 28 degrees north.

Run the measurement from the centre of the Earth and the order flips. According to the US National Ocean Service, Chimborazo’s summit is around 6,384.4 kilometres from the centre, against about 6,382.3 kilometres for Everest. The volcano wins by roughly 2.1 kilometres despite being far shorter.

Why the bulge does the work

The size of the bulge is the part that gets lost. Sea level at the equator sits about 21 kilometres farther from the centre than sea level at the poles. That is an order of magnitude larger than the 2-kilometre gap between Chimborazo and Everest.

So the contest between the two mountains is almost a footnote on top of a much bigger effect. Most of Chimborazo’s advantage comes not from the mountain at all, but from where it stands. The equatorial sea-level surface it rises from is already farther out than the Himalayan one. The volcano then adds a few kilometres on top of a base that starts higher in this particular sense.

Chimborazo is not even the tallest peak in the Andes. By this measure it leads only narrowly. Huascarán, also in the Andes, comes second by roughly ten metres, and at least two dozen other summits sit farther from the centre than Everest does. The title is real, but the margin is thin and the field is crowded.

What “closest to space” does and does not mean

The fact often arrives wrapped in a stronger claim: that standing on Chimborazo puts you closer to outer space, or to the Sun, or to the stars, than anywhere else on Earth. The first version is defensible under one definition. The others do not hold up.

Closest to the Sun is the easiest to dismiss. Earth’s distance from the Sun varies by about five million kilometres over the course of a year because the orbit is not a perfect circle. That swing dwarfs a 2-kilometre difference between two mountains by a factor of more than a million. The Sun also moves across the sky, so no fixed point on the ground holds any standing claim to being nearest to it. The same applies to the stars.

Closest to outer space depends entirely on what you mean by space. If space is defined as distance from the planet’s centre, then yes, Chimborazo’s summit is the piece of solid ground that pokes out farthest, and a line drawn straight out from the core exits the Earth’s surface there at the greatest radius. If instead space is taken to begin at a set altitude above sea level, which is the more common convention, then Everest’s summit, sitting some 2,600 metres higher above the sea, is the closer of the two. Both statements are true. They answer different questions.

The honest version is narrow. Chimborazo’s summit is the point on the solid surface of the Earth farthest from the geometric centre. That is a statement about radius, not about altitude or atmosphere.

The expedition that measured the bulge

The bulge that produces all this was not always known. Confirming it was the explicit goal of one of the more ambitious scientific expeditions of the eighteenth century. The French Geodesic Mission, which worked in the region around Chimborazo in the 1730s and 1740s, was sent to measure the length of a degree of latitude near the equator. Comparing that with a measurement taken in the far north would settle whether the Earth was flattened at the poles or stretched along them. The equatorial results confirmed the flattened, oblate shape, as the Library of Congress notes in its account of the mission.

There is a neat closure in that. The expedition went to the foot of Chimborazo to prove the Earth bulges at the equator. That same bulge is the entire reason Chimborazo now holds its title.

For a stretch afterwards, the volcano was widely thought to be the highest mountain on Earth, the tallest that had been measured with any accuracy. Alexander von Humboldt climbed high on it in 1802, still under that impression. The belief held until the Great Trigonometrical Survey of India began measuring the Himalayas in the 1820s and put Everest and its neighbours in their place.

What makes Chimborazo worth a second look is not that it beats Everest. It is what the comparison exposes: that “highest” and “farthest from the centre” are different measurements, that the gap between them is mostly the shape of the planet rather than the mountains on it, and that a fact which sounds like trivia is really a small lesson in being precise about which distance you mean.