The Planck probe mapped cosmic background radiation and measured it with exceptional precision. Among other things, the results contributed to determining the properties of density fluctuations (“seeds of galaxies”) in the early universe and to shedding light on their origin. The Planck group analysed the results and studied cosmological models to explain the results.
The Euclid mission will map the three-dimensional structure of the observable universe. The primary goal of the mission is to solve the problem of “dark energy”, that is, why the expansion of the universe is accelerating.