Mathilde Renard

At the edge of our solar system supposedly lies an immense planet. Five to ten times the size of the Earth. Several international teams of scientists have been competing in a frantic race to detect it, in uncharted territories, far beyond Neptune. The recent discovery of several dwarf planets, with intriguing trajectories, have put astronomers on the trail of this mysterious planet. Why is this enigmatic planet so difficult to detect? What would a ninth planet teach us about our corner of the universe? Could it help us unlock some of the mysteries of our solar system?

At the edge of our solar system supposedly lies an immense planet. Five to ten times the size of the Earth. Several international teams of scientists have been competing in a frantic race to detect it, in uncharted territories, far beyond Neptune. The recent discovery of several dwarf planets, with intriguing trajectories, have put astronomers on the trail of this mysterious planet. Why is this enigmatic planet so difficult to detect? What would a ninth planet teach us about our corner of the universe? Could it help us unlock some of the mysteries of our solar system?

In 1924, a garden city, called “Ungemach”, was inaugurated in Strasbourg; it was restricted to couples who bore “healthy and fertile strains”. This officially eugenicist experience was endorsed by both political and scientific authorities, and the selection system lasted until the 1980s! To understand the genesis of such a project, it is necessary to revisit the history of eugenics. We will first go to England, where the concept was born and developed in the 1880s. Then to the United States, Switzerland, the Nordic countries, Japan, where, since the 1920s, large-scale sterilization policies have been implemented to eradicate health and social "defects", long before Nazi Germany. This question of eugenics is a universal one; its implementations were numerous and it still permeates ethical debates on medically assisted procreation techniques or Transhumanism today.