On Sunday, December 9, Riccardo Giacconi passed away. He was the father of X-ray astronomy and was awarded the Nobel Prize in Physics in 2002 for his contributions to that field.

Riccardo Giacconi was born on October 6, 1931, in Genoa, Italy. He obtained a degree in physics at the University of Milan with a specialization in the research on cosmic rays. In 1956, he moved to the USA, where he carried out research first with the University of Princeton and then at AS&E (American Science and Engineering), where he started developing the first instruments to detect cosmic X-rays.

In 1962, Riccardo Giacconi discovered the first extraterrestrial X-ray source, named Scorpius X-1. In 197,0 he oversaw the launch of NASA’s Uhuru satellite, the first specialized in X-ray astronomy, followed in the following decades by increasingly sophisticated satellites such as the Einstein Observatory (HEAO-2) in 1978, designed while Giacconi was director of the Harvard Smithsonian Center for Astrophysics, to NASA’s Chandra X-ray Observatory in 1999.

Although Riccardo Giacconi is remembered above all for the development of X-ray astronomy, he also worked in other specializations. In particular, in 1981, he became the first director of the Space Telescope Science Institute, the center of scientific operations for what was then another pioneering project, the Hubble Space Telescope. Giacconi kept that office until 1993 and directed the search for a solution to correct the primary mirror flaw discovered after Hubble’s activation in space.

After that experience, between 1993 and 1999 Riccardo Giacconi was general director of ESO, directing, among other things, the construction of the Very Large Telescope (VLT), an observatory on which various instruments were installed over the following years, making it one of the best ground-based telescopes in the world.

In 2002, Riccardo Giacconi was awarded the Nobel Prize for his pioneering contributions to astrophysics, which led to the discovery of cosmic X-ray sources. It’s the most famous among the awards he received, but there were several others in Italy, in the USA, and in other countries. In Italy, he also received the honor of Order of Merit of the Italian Republic (Cavaliere di gran croce dell’Ordine al merito della Repubblica italiana) in 2002 and the Italian Medal of Merit for Culture and Art (Medaglia d’oro ai benemeriti della scuola, della cultura e dell’arte) in 2005.

Riccardo Giacconi returned to work with NASA as principal investigator in the Chandra Deep Field-South project of the Chandra X-ray observatory. He leaves a huge legacy, as today X-ray astronomy means studying a part of the universe full of violent events that generate those strong electromagnetic emissions, such as neutron stars and black holes.