Olga Zamora

The maximum number of artificial satellites that can safely orbit the Earth could be reduced due to the increase in greenhouse gas emissions of human origin, according to a modelling study. The increase in these gases may result in a reduction in the density of the planet's orbital space. Between 2000 and 2100, the carrying capacity of satellites between 200 and 1,000 kilometres altitude could be reduced by between 50 and 66%, estimates the study published in Nature Sustainability.

Space debris and satellites orbiting close to Earth have proliferated in recent years. Two articles in Nature Astronomy warn of their impact on light pollution. In the first, a team calculates the increase in the brightness of the night sky and warns of the effect on ecosystems and astronomical observations from Earth. In the second, which is a commentary, the authors call for limiting the production of artificial light and the number of satellites in orbit, calling on the scientific community to take on the big space and big light companies. Both articles are co-signed by Salvador Bará, from the Agrupación Astronómica Coruñesa, and the second by Fabio Falchi, from the University of Santiago de Compostela.