The International Bureau of Weights and Measures says lunar clocks have drifted so far that nothing on the moon is open.
Lunar clocks run 56 microseconds a day fast, so a weights bureau study added it up over four billion years. The moon is three years ahead of Earth and the day there is Sunday. Astronauts have been told to pack sandwiches and not expect the shops to open.
The moon has missed church. That is the main finding of our study, and I want to be clear about it before anything else. It is Sunday on the moon. It has been Sunday there for some time, and nobody told the moon.
Here is how we know. Clocks on the moon run faster than clocks on Earth. The gap is about 56 microseconds a day. A microsecond is a millionth of a second. Gravity is weaker up there, so time goes a little quicker. This part is settled. James Olthoff of the International Bureau of Weights and Measures explained it to NPR and nobody argued.
What nobody had done was add it up. The moon has been running fast for about four and a half billion years. We did the sum on a Sunday afternoon with a pencil. It comes to roughly a thousand days. The moon is three years ahead of us, give or take a weekend.
So on the moon it is already 2029. We checked twice. The second check used a different pencil. Both came out the same, and when you count forward the day of the week lands on a Sunday. We cannot rule out that it is a different Sunday. That is our one hedge.
Our control group was fourteen kitchen clocks in Paris. A control group is the thing you leave alone to see what normal looks like. All fourteen said Earth time. None of them had missed church. Our p-value was small. A p-value is how likely we are to be wrong by accident. We did not test for being wrong on purpose.
Some people will say other things are happening in space. Japan is sending a spacecraft to a moon of Mars to grab a piece of it and fly the piece home. Fine. It is a rock. It will arrive eventually and we will put it in a drawer.
Monday is not coming
The Sunday problem is harder. Several nations plan to land people on the moon in the next few years. They will arrive on Earth time and step out into a lunar Sunday. Dr Anneliese Grund keeps the second at the Bureau, which means she is the person the second belongs to. She put the risk plainly.
If you land on a Sunday there is nothing to do. The shops are shut. The post does not go. You sit in the lander and wait for Monday, and Monday is not coming, because the moon has already had it.
The Bureau wants to fix this with a proper lunar clock. The idea is to give the moon its own time and stop pretending it keeps ours. That is sensible and it is also three years too late. The moon has seen things we have not. It knows how two elections went. It knows who won the cup. It has watched the final episode of every show we are still waiting on, and it will not say.
We have asked the first crews to pack sandwiches. We have asked them to bring a spare pencil. If it is still Sunday when they get there, they should sit quietly and not expect the bins to be collected. The moon will get to us in its own time, which is three years from now, last Sunday.
