Planck mission: challenges and expectations for cosmology and particle physics

The Planck satellite of the European Space Agency, scheduled to be launched on May 14th, 2009, is designed to observe the microwave sky with unprecedented frequency coverage, sensitivity and angular resolution, in order to provide the most accurate measurement of the anisotropies in the Cosmic Microwave Background. We review here the present status of the mission as well as the future milestones, give the main remarks on the forthcoming phase of data acquisition, analysis and interpretation, focusing on the leadership that Italian scientists and institutions represented for the entire Planck collaboration in the instrumental study, design, construction, and data analysis of one of the two instruments on board, the Low Frequency Instrument \citep{mandolesi_etal_2004}. We describe the main scientific expectations and challenges for cosmology and particle physics, represented by this mission.