Earth observations from satellites located in deep space offer the exciting opportunity to look at the Earth in a bulk thermodynamic sense, particularly as an open system exchanging radiative energy with the Sun and space, in a way never done before – “the Earth as a whole planet”, astronomers would say. This is a fundamental scientific goal with very appealing prospects for Earth sciences. Climate research requires stable, accurate, long-term observations made with adequate spatial and temporal resolution in a synoptic context. From deep-space vantage points we can, with a single spacecraft, sample the outgoing energy from virtually an entire hemisphere of Earth at once with high temporal and spatial resolution. Measured spectral radiances will be transformed into data products (e.g., ozone; aerosols; cloud fraction, thickness, optical depth, and height; sulfur dioxide; precipitable water vapor; volcanic ash; and UV irradiance). At present this is only partially possible by combining data from low Earth orbit and geostationary orbit satellites into an asynoptic composite of hundreds of thousands of pixels - rather like assembling an enormous jigsaw puzzle. Another advantage of the deep-space perspective is that, because of the integral view of the planet's hemispheres, the observations will simultaneously overlap the observations of every LEO and GEO satellite in existence, making possible a unique synergy with great potential benefits for the Earth sciences.