Editorial: Earth observations from the Deep Space: 10 years of the DSCOVR mission

Abstract

The unique near-backscatter view geometry of EPIC led to creation of several new Earth science products. One of them is the diurnal course of "sunlit leaf area index" SLAI (Yang et al., 2017). It characterizes the area of green leaves at a given time intercepting the direct sunlight and depends on canopy structural organization. Another one is specular reflection from horizontally oriented ice crystals in clouds (Marshak et al., 2017). The first operational glint product was released in May 2021 (https://epic.gsfc.nasa.gov/science/products/glint). Collected EPIC data are processed on a semi-operational basis providing a suite of atmospheric, land and ocean data products. Many of the processing algorithms have been described in the earlier Research Topic of Frontiers in Remote Sensing published 5 years ago, "DSCOVR EPIC/NISTAR: 5 years of observing Earth from the first Lagrangian point," that featured 23 papers providing a holistic view of the Earth science from DSCOVR.Current special issue titled "Earth observations from the Deep Space: 10 years of the DSCOVR mission" is the continuation of the previous Research Topic. It features 20 papers focused on science data analysis and various applications but also covering achieved progress in sensor calibration and processing algorithms.Below is a brief overview of the scope of the Research Topic. Cede et al. (2025) discusses radiometric stability of EPIC and NISTAR. Study found no drift over the entire mission in the EPIC 551 nm channel and NISTAR photodiode channel (200 to 1100 nm). Changes in EPIC calibration were very small, ranging from a maximum degradation of 3% over 10 years in the short UV channels to smaller to negligible for other channels. Such remarkable performance is largely attributed to the L1 orbit located beyond the Earth radiation belt and providing thermal stability due to the Sun positioned on the same shielded side of the spacecraft. This unique perspective highlights the value of L1 orbit as a deep space outpost for continued long-term Earth monitoring. (2025). Constructed high resolution multispectral maps of both sides of the Moon in 10 EPIC's channels helped Gorkavyi et al. (2026) to reveal mineralogical differences between the two sides of the Moon. The paper showed that the Moon images obtained by EPIC а have significant scientific value. To learn about a deep space mirage (Gaia's crown) check the paper by Blank et al. (2025).Beyond the individual advances reported in this collection, several cross-cutting themes emerge. The sustained radiometric stability of EPIC and NISTAR demonstrates that deep-space platforms can support long-duration climate-relevant records. The continuous full-disk perspective has elevated the study of diurnal changes in clouds, surface processes, and atmospheric composition to a truly global scale, enabling more rigorous evaluation of global climate and Earth system models and clearer dynamical interpretation. In addition, co-located measurement of aerosols, cloud fields, and Earth's reflected energy from a single vantage point provide stronger constraints on their mutual interactions than multi-platform approaches. Together, these developments define L1 observations as a coherent and complementary component of the modern Earth observing system.Taken together, the contributions in this Research Topic mark a milestone in the maturation of deep-space Earth observation. Over the past decade, DSCOVR has demonstrated that viewing Earth from L1 offers a systems-level perspective that integrates variability across processes and time scales within a single, globally consistent framework. Looking ahead, the experience gained from this mission suggests that sustained L1 observations could play an expanded role in future climate observing architectures, not only as independent reference records, but also as integrative platforms linking polar and geostationary measurements. As the global observing system evolves, deep-space perspectives may become increasingly central to how we monitor and understand a changing planet.19. Ziemke J., N. Kramarova, S. M. Frith, K.-L. Huang, K. Baek and J. Herman, 2025