Like the flower-covered Semnoz summit meadow, the Milky Way is adorned with myriad stars and gas nebulae. To its left, the planets Jupiter and Saturn are the stars of the 2020 summer sky. The largest planet in the Solar System, here the brightest, orbits the Sun in nearly 12 years. Its cousin, the ringed planet, takes just over 29 years to orbit the Sun. So Jupiter is catching up with Saturn in their motion relative to the constellations, and doubling it every 20 years on average. This will be the case on 21 December 2020, when they will be very close, visible in the same field of a telescope.