Final answer:
The name of the EOS satellite whose mission is to monitor Earth's water cycle is GRACE-FO (Gravity Recovery and Climate Experiment Follow-On).
Step-by-step explanation:
The name of the EOS satellite whose mission is to monitor Earth's water cycle is GRACE-FO (Gravity Recovery and Climate Experiment Follow-On). GRACE-FO is a joint mission between NASA and the German Research Centre for Geosciences (GFZ).
It was launched in May 2018 and uses microwave ranging instruments to measure variations in Earth's gravitational field, which provides valuable information about the distribution of water on the planet.