The ladder to the Moon

Your ladder in Clamber is measured against real things, from a statue you could walk around to a spacecraft now in interstellar space. This is a walk up the ladder, one landmark at a time, with the true height of each.

There are 25 landmarks in all, and 930 points reaches the Moon. Each name below links to its own page, with the story behind the number.

Ground level: five things made by people

Clamber starts with something you could almost touch. The Statue of Liberty stands 93 m tall, torch included. It is a good first rung because anyone can picture it, and it sets the scale for what follows.

The Great Pyramid of Giza is 139 m today and was taller when it was new. For nearly four thousand years nothing built by humans was higher. The Eiffel Tower then reaches 330 m, the Empire State Building reaches 443 m, and the Burj Khalifa tops out at 828 m. That last one is the end of the road for buildings: nobody has built higher.

The sky: weather, mountains and aircraft

Once you leave the buildings, the ladder passes the fair-weather clouds at about 2.0 km. Then come the two great mountains: Mount Kilimanjaro at 5.9 km and Mount Everest at 8.8 km. Everest is the highest summit anywhere on land, and at its summit the air pressure is about a third of what it is at sea level.

Just above it, at about 11 km, is the cruising height of an airliner. You are now higher than any mountain, and every long-haul passenger has been here. The Concorde's cruise at 18 km is where the sky begins to darken, and the highest skydive at 41 km shows what it takes for a person to fall from that height: a pressure suit and a balloon.

The edge of space

The Kármán line at 100 km is the usual border of space. It is a convention, not a wall, but it is the point where the air is too thin for wings to work. Past it, you are no longer in the atmosphere in any practical way.

The next three landmarks are all things that orbit. Gagarin's orbit reached 327 km in 1961. The International Space Station circles at 408 km, and the Hubble Space Telescope at 540 km. All three are in low Earth orbit, a region where the distances still feel like a road trip.

The belts and the planet itself

At around 1,000 km the inner Van Allen belt begins. It is a ring of charged particles held by Earth's magnetic field. Beyond it, the scale changes. One Earth stacked is 12,742 km, the width of the whole planet: the ladder has become taller than the place it started from.

Satellites that never come down

The GPS satellites orbit at 20,200 km, and the geostationary ring sits at 35,786 km. The second is the famous one: a satellite there takes exactly one day to go round, so it hangs over the same spot on the equator. The first group handles navigation, and the second carries much of the world's satellite television and weather watching.

Halfway, and then the Moon

Halfway to the Moon is 192,200 km. It splits the distance to the Moon in two, and shows how far away the Moon is when you compare it with buildings and mountains. Then the The Moon itself, at 384,400 km. At this point the climb is complete: 930 points will take a daily climber to the top, and the ladder in a daily game stops here.

Beyond the Moon, in Endless

In Endless mode there is no ceiling. Mars at its closest is 54.6 million km away, and the The Sun is 149.6 million km. Jupiter is at 588.0 million km when it is closest to us. The last landmark, Voyager 1, is a spacecraft launched in 1977 that is now around 25.0 billion km from home, and still sending a signal.

Why the ladder is not a straight line

The distances on the ladder run from under a hundred metres to billions of kilometres, so Clamber cannot draw them to scale. From the ground to the first landmark the ladder is a straight line. After that, the heights are spread on a logarithmic scale, where each step up multiplies the real distance by a similar amount. That is why a rung near the top of the ladder covers far more real distance than a rung near the bottom, and why the landmarks keep arriving fairly regularly even as the numbers explode.

The points shown on each landmark page tell you where it sits. Reaching the Moon takes 930 points, and the page for each landmark says how many holds that needs even if you give nothing but the rarest answers. A fall drops you to just below the last landmark you passed, so the landmarks also act as steps you can slide back down.

Ready to start? Play today's climb, read how to play, or learn how to find rare answers so you can get higher.