A solar photometer positioned high on the hillsides of the Teide, in Tenerife, on top of the majority of clouds and airborne dust monitors night-time variations in the moonlight to assess and supervise the gauging of Earth-observing instruments.
Marc Bouvet, head of the European Space Agency (ESA) project, explained on the ESA website that such pieces of equipment are carefully gauged prior to their deployment but, when they reach in space, the performance of these pieces of equipment may fluctuate as a consequence of radiation, optical contamination or technical alterations.
He also points out the fact that although the Earth’s surface is in constant progression, the Moon’s surface has remained the same for several million years, apart from the occasional collisions with meteorites. That is why the sunlight mirroring off the Moon’s surface is a flawless calibration resource for the telescopes that will be deployed in space to observe our planet.
The solar photometer in Spain, along with similar devices in the world, would be a benchmark of calibration for future Earth-observing instruments
The device mounted on the Teide is a sun photometer, like the ones widely distributed around the world, to measure atmospheric particles. On the other hand, it was specifically adjusted to work at night rather than in the daylight to be able to accurately assess the moonlight.
The consortium in Tenerife, supported by ESA’s Basic Activities project, is working with the National Physics Laboratory (NPL) of the United Kingdom, the University of Valladolid, and the Flemish Institute of Technological Research of Belgium in the development of the project.
In the opinion of Marc Bouvet, the project involving the solar photometer in Tenerife, along with similar projects which are conducted, as we speak, in China and the United States, gave birth to a lot of hopes, as their potential to succeed would allow the future Earth-observing instruments to have a benchmark of calibration, that is, the moonlight, which would facilitate the cross-analysis of datasets and enhance our general understanding of our own planet.