Solar System Simulator · What if? · the Moon
How far is the Moon, really?
384,400 km. 238,855 miles. Thirty Earths side by side. Nearly every picture you have seen puts it far too close — here it is drawn to scale, and then you fly there on the real trajectory.
Why every picture lies
Draw Earth as a coin and the Moon at the right distance and it lands a third of a metre away — off the page, off the screen, out of the frame. So diagrams cheat, and the Moon sits next door. The simulator cheats by default too, compressing distances so the whole solar system fits, but the lesson switches the view to true scale: Earth on the left, the Moon on the right, at their real relative sizes and the real gap, and the Moon is very small and very far.
The basketball scale
Shrink Earth to a basketball, about 24 cm across. The Moon becomes a tennis ball — a bit over a quarter of Earth's diameter — and it sits about 7 metres away: across a large room, not on the same table. The geostationary satellites that carry TV and weather pictures, at 6.6 Earth-radii up, orbit just 80 cm from the ball; the International Space Station hugs its surface, a couple of millimetres out. Everything humans have built in space, bar the probes that left, is in the first tenth of the way.
All the planets fit in between
At the Moon's average distance, the other seven planets — Mercury, Venus, Mars, Jupiter, Saturn, Uranus and Neptune — lined up edge to edge would just fit into the gap between Earth and the Moon, with a few thousand kilometres to spare. Jupiter alone is eleven Earths wide. It is a useful way to feel that the "empty" gap is enormous.
Not a fixed number
The Moon's orbit is slightly elliptical, so the distance swings between about 363,364 km at its closest and 405,580 km at its farthest — 225,784 to 252,015 miles — over each month. A full Moon at the near end of that range is the "supermoon" of the headlines, about 14% wider than one at the far end.
Flying there
Light makes the trip in 1.3 seconds. Apollo took about three days: from a parking orbit the spacecraft fired its engine once to reach 10.9 km/s — the translunar injection — and coasted, slowing under Earth's pull until the Moon's gravity took over. The simulator solves the same injection from scratch (its answer, 10.86 km/s, matches the Apollo figure) and integrates the probe under Earth's and the Moon's gravity together, arriving within 144 km of the surface after about 2.8 days. Watch the Moon during the trip: it moves about 40° along its orbit while Earth turns three times, the real 27-to-1 ratio between a day and a month.
What the simulator does
- The view switches to a true-scale Earth–Moon scene: real relative sizes, real distance, a geostationary ring for comparison.
- A probe leaves Earth at the Apollo translunar speed and flies a genuinely integrated three-day trajectory under both bodies' gravity.
- The debrief gives the distance in kilometres, Earth-diameters and basketball metres, and how long light takes.
Questions people ask
How far is the Moon in miles?
About 238,855 miles on average, ranging from roughly 225,784 miles at its closest to 252,015 miles at its farthest each month.
How long does it take to get to the Moon?
About three days for an Apollo-style flight, which is what the simulator flies. Light takes 1.3 seconds. A car at highway speed, if roads went that way, would need about 160 days.
Is the Moon moving away from Earth?
Yes, by about 3.8 cm a year, measured by bouncing lasers off reflectors the Apollo astronauts left behind. Tides carry a little of Earth's spin into the Moon's orbit.
Why does the Moon look so close in photos?
A telephoto lens compresses distance, and diagrams shrink the gap on purpose so both bodies fit. Drawn to scale on a screen, the Moon is a small dot far from Earth — which is what the lesson shows.
Keep going
Every number on this page comes from the simulator's own physics or the real mission record it is checked against. Where the simulation and reality differ, the page says so.