Planck (spacecraft)

Planck was a European Space Agency (ESA) space observatory operating from 2009 to 2013. It was designed to map the cosmic microwave background (CMB), the afterglow of the Big Bang, with unprecedented accuracy. By measuring the CMB's temperature fluctuations, Planck aimed to improve our understanding of the universe's origin, composition, and evolution.

The spacecraft was named after Max Planck, the German physicist who originated quantum theory. Planck carried two high-frequency instruments: the Low Frequency Instrument (LFI) and the High Frequency Instrument (HFI). These instruments allowed it to observe the sky in nine frequency bands, covering a broad range of wavelengths from the microwave to the far-infrared.

Planck's data provided the most detailed map of the CMB ever created. These maps have been used to refine cosmological parameters, such as the age of the universe, its rate of expansion (the Hubble constant), and the amount of dark matter and dark energy it contains. Planck also contributed to our understanding of the formation of galaxies and the interstellar medium.

Following the completion of its primary mission, Planck's data continues to be analyzed by scientists around the world, yielding new insights into the cosmos. The mission significantly advanced our knowledge of cosmology and established a new standard for CMB observations. The spacecraft was decommissioned in 2013.