Deep space exploration, serving as a pivotal avenue for uncovering the universe's mysteries and
fostering sustainable development, has emerged as the foremost strategic frontier in space technology. After
decades of development, this technology has been widely used in the exploration of various celestial bodies in the
solar system. In February 2015, the first deep space exploration satellite targeting the Earth, the Deep Space
Observatory (DSCOVR), was successfully deployed at the Sun-Earth Lagrange Point 1 (L1), providing new
perspectives and data for the study of Earth system science, while also posing new challenges to traditional
satellite data research. This paper comprehensively analyzes more than 100 related papers and conference
summaries published on the official website of the National Aeronautics and Space Administration (NASA) since
the launch of DSCOVR. From the three levels of basic research, applied research and special research, this paper
comprehensively reviews the development status, advantages and future development direction of deep space
earth observation. This study reveals that deep space Earth observation can integrate existing satellite-aircraftground
systems, establishing a benchmark for multi-source data fusion to create globally comprehensive, highfrequency
temporal, and multi-spectral datasets for an integrated Earth observation system. It provides temporally
consistent, spatially continuous, and spectrally stable global observation data, showing significant potential in the
study of large-scale geophysical phenomena across the atmosphere, biosphere, hydrosphere, and lithosphere.
Future advancements in sensor innovation, optimized detection technologies, and diversified observation points
are expected to enable all-temporal, all-directional, and all-dimensional Earth observation. This will enhance our
understanding of physical, chemical, and biological systems on Earth.