CNES projects library
What is the Sun’s diameter? In the 17th century, French astronomer Jean Picard was the first to make rigorous measurements. A few centuries later, from 2010 to 2014, the Picard microsatellite acquired extremely precise data to measure the Sun’s rate of rotation, the flattening of its poles and radiated power (total and spectral irradiance), while also probing its interior (helioseismology).
Research scientists are today analysing and exploiting this treasure trove of data that will tell us more about our Sun’s inner workings and its impact on Earth’s climate.
CNES initiated the Picard mission and was responsible for developing the satellite’s Myriade bus and for in-orbit operations.