The Earth’s albedo is one of the least studied fundamental climate parameters. The albedo is a bi-directional variable, and there is a
high degree of anisotropy in the light reflected from a given terrestrial surface. However, simultaneously observing from all points on
Earth at all reflecting angles is a practical impossibility. Therefore, all measurements from which albedo can be inferred require assumptions
and/or modeling to derive a good estimate. Nowadays, albedo measurements are taken regularly either from low Earth orbit satellite
platforms or from ground-based measurements of the earthshine from the dark side of the Moon. But the results from these different
measurements are not in satisfactory agreement. Clearly, the availability of different albedo databases and their inter-comparisons can
help to constrain the assumptions necessary to reduce the uncertainty of the albedo estimates. In recent years, there has been a renewed
interest in the development of robotic and manned exploration missions to the Moon. Returning to the Moon will enable diverse exploration
and scientific opportunities. Here we discuss the possibility of a lunar-based Earth radiation budget monitoring experiment, the
Lunar Terrestrial Observatory, and evaluate its scientific and practical advantages compared to the other, more standard, observing platforms.
We conclude that a lunar-based terrestrial observatory can enable advances in Earth sciences, complementary to the present
efforts, and to our understanding of the Earth’s climate.