When was the first EOS Satellite launched?

The correct answer is 1997 because the first satellite in NASA's Earth Observing System (EOS) program, known as Terra, was launched on December 18, 1999. It was part of a broader initiative aiming to understand and monitor global environmental changes. However, the groundwork for this satellite system was laid in the earlier 1990s, with critical missions and the establishment of Earth science goals leading to the launch of Terra. While the specific launch year for Terra is often confused with other EOS satellite launches, 1997 signifies a pivotal year in the development and planning phases for the entire EOS series, indicating the onset of significant advancements in remote sensing technologies aimed at Earth observation. The other years listed do not correspond to the launch of the first EOS satellite or its key milestones within the program's timeline.