Why one day on Mercury lasts two Mercury years

Mercury circles the Sun in 88 Earth days and spins once every 58.6 days. That odd pairing, three spins for every two orbits, means one sunrise to the next takes about 176 Earth days, twice as long as its year.

Fly Mercury round the Sun yourself, count the "noons", and see why near the closest point the Sun can seem to stall and slide backwards across the sky.