To study Earth’s climate, we need to measure the Sun. ☀️ Proba-3 is two spacecraft flying in perfect formation. While one blocks the Sun to let us study its faint outer atmosphere, the other stays sunward, carrying a tiny but mighty instrument called digital absolute radiometer (DARA). DARA keeps track of the Sun’s total energy output — a vital variable for climate science, since 99.978% of Earth’s energy comes from the Sun. And it does so with precision down to a single watt per square metre. All from 60 000 km above Earth. 📹 europeanspaceagency 🖥️ ESA - P. Carril, 2013