The Earth Observer: Offering Perspectives from Space through Time

An Intertwined History: The Earth Observer and EOS The Earth Observer, a newsletter issued for more than 36 years, will release its last online content at the close of 2025. This newsletter evolved in parallel with NASA’s Earth Observing System (EOS). It is almost impossible to speak of this newsletter without mentioning EOS. As The Earth […]

Terra: The End of An Era

Introduction Launched into the night sky nearly 26 years ago, on December 19, 1999, from Vandenberg Air Force Base (now Space Force Base), Terra was NASA’s first Earth Observing System (EOS) Flagship mission to study Earth’s land surface from space via a coordinated series of polar-orbiting and low-inclination satellites that produce long-term global observations useful […]

Terra: The End of An Era

Introduction Launched into the night sky nearly 26 years ago, on December 19, 1999, from Vandenberg Air Force Base (now Space Force Base), Terra was NASA’s first Earth Observing System (EOS) Flagship mission to study Earth’s land surface from space via a coordinated series of polar-orbiting and low-inclination satellites that produce long-term global observations useful […]

The State of CERES: Updates and Highlights

Introduction The Clouds and the Earth’s Radiant Energy System (CERES) was initially designed in the late-1980s and early-1990s as a facility instrument for NASA’s Earth Observing System (EOS). Since its inception, NASA’s Langley Research Center (LaRC) has led this effort. CERES has a long history with seven different instruments flying on five different missions since […]

OPERA: Addressing Societal Needs with Satellite Data

Introduction The Observational Products for End-Users from Remote Sensing Analysis (OPERA) project represents a strategic initiative designed to address critical satellite data needs identified by federal agencies. Established in 2021 by the NASA/Jet Propulsion Laboratory (JPL), OPERA responds to priorities identified by the Satellite Needs Working Group (SNWG), an interagency body convened by the White […]

Sentinels in the Sky: 50 Years of GOES Satellite Observations

Introduction In an era where satellite observations of Earth are commonplace, it’s easy to forget that only a few decades ago, the amount of information available about the state of Earth’s environment was limited; observations were infrequent and data were sparsely located. As far back as the late 1950s, there were primitive numerical weather prediction […]

Keeping Up with PACE: Summary of the 2025 PAC3 Meeting

Introduction Launched in Feb. 2024, NASA’s Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) mission is a cornerstone of Earth system science designed to deepen our understanding of how these environmental and biological components come together to influence our climate, carbon cycle, and ecosystems. PACE has funded three supporting components: the PACE Postlaunch Airborne eXperiment (PACE–PAX), the […]

Sentinel-6B Extends Global Ocean Height Record

Introduction On November 16, 2025, the Sentinel-6B satellite launched from Vandenberg Space Force Base (VSFB) in California. The mission is a partnership between NASA, the National Oceanic and Atmospheric Administration (NOAA), and several European partners – the European Space Agency (ESA), the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), the French Centre National […]