André Brahic, lord of planetary rings, passed away – 1 Photo
“what is the purpose that would be that we should choose to be born rather than not exist? Speculation about the sky and the order of the whole cosmos “ and spoke the Greek philosopher Anaxagoras at V th century BC. AD It was hard not to share this idea when we talk Brahic André listened with enthusiasm, the latest advances in planetary via major projects like space probes Voyager and Cassini, and simply of Science as illustrated so well the video below. His glazed intellectual ferment of humours traits, sometimes aggressive, had made the world-renowned astrophysicist who in 1984 co-discovered the rings of Neptune, a regular TV sets since 1980 where it is sometimes found in the company Hubert Reeves and Jean-Pierre Luminet other major extension.
He has, unfortunately, dying from May 15, 2016 as a result of cancer.
In 2011, he gave a long interview to Futura-Sciences, despite the fact that he was overwhelmed by its many activities, including as a member of the team imaging of the Cassini mission exploring Saturn and currently its moons. The researcher explained her story.
In this video André Brahic clearly share the belief of many great scientific minds over the centuries . Science is the greatest adventure ever undertaken by humanity and rational thinking that accompanies it should be a major component of life and society. © YouTube
From simulation of galaxy images of planetary rings
Born on November 30, 1942 in Paris, he began as Jean-Pierre Luminet, by doing mathematics studies. License, like many other French astrophysicists become famous, is under the influence of course (it takes optional) and enthusiasm Evry Schatzman it definitely rocked the world of ‘astrophysics. The charisma and personality of the man who was the father of French astrophysics deeply influence, but this is his meeting with the mathematician and astronomer Michel Hénon, his thesis advisor, who played a key role in his career.
Henon is considered one end of the top scientists of the twentieth th century. His work on stellar dynamics and problems-body authoritative. In the tradition of Henri Poincaré, he explored the physics of chaos and discovered the famous strange attractor that bears his name. André Brahic will honor him in an exciting conference that one can find in a video of the Institut Henri Poincaré.
In the early 1970s, André Brahic studied collisions of a system of N interstellar clouds to understand the flattening of spiral galaxies and training records. To test his model, he applied to the formation of Saturn’s rings, considered as a whole-body rotating around the planet and undergoing incessant mutual collisions. This star had seemed initially a priori unattractive compared to the world of stars and galaxies, until he realized that the biggest names in astronomy it was broken teeth. Galileo, Cassini, Laplace, Maxwell and Poincare to name a few, have dedicated part of their lives without being able to solve all the problems of these rings.
But the invention of computers that can do complex simulations and launching space probes that give the opportunity to closely observe the planets of the solar system have changed everything. The rings of Saturn have become real physics laboratories at hand, and we will need some additional centuries to understand everything.
Finally, while he expected to spend a few months studying the Rings, André Brahic will be spent over thirty-five years. He did not regret the decision because this will be the chance of a lifetime. Indeed, when the mission Voyager preparation works were launched, one in the world studying the evolution and dynamics of Saturn’s rings. It is natural that the French researcher then proposed to join the Voyager imaging team to analyze data on the rings.
Five pictures 450 seconds pause was taken May 15, 2016, between 8:11 p.m. ET 20:52, the asteroid (3488) BRAHIC, named in honor of astrophysicist. We thus see the stars scroll, and the asteroid itself is visible in the circle at the top right of this composite image. © David Romeuf
The adventure of Voyager and the discovery of the rings of Neptune
The probes Voyager I and Voyager II were built Jet Propulsion Laboratory in Pasadena, California. JPL depends on the famous The California Institute of Technology where Richard Feynman was one of the teachers. In the early 1960s, at the conclusion of one of his famous physics course on hydrodynamics, the great theorist of elementary particles prophesied that when the exploration of the Solar System is more advanced, it would be a salutary lesson for physics. We then see a wealth of phenomena, largely unpredictable the current stage of development of human intelligence emerge from simple equations such as the laws of mechanics and gravitation of Newton, and especially those of fluid mechanics Navier-Stokes equations.
This richness and diversity that continue to surprise researchers, are present in the solar system, as beautifully shows the work of André Brahic he published Odile Jacob, entitled from fire and ice, fiery planets . The author also tells the following story, among many others: “ Within the imaging team Voyager probes in the 1980s, we had fun before each match to predict physiognomy of the stars just before visiting. Whoever lost the paris that we launched invited his colleagues in the best restaurant nearby. Upon arrival, everyone called everyone! To astronomers, we become foodies! . ”
Richard Feynman, André Brahic has only to see it several times, but in the early 1980s, another star was indeed present in the imaging team Voyager JPL: Carl Sagan. They become very close friends and that’s how one of the men behind the Seti program and Golden Record Voyager will give a public lecture with André Brahic in Toulouse . As he told Futura-Sciences, André Brahic felt in perfect accord with the approach of Carl Sagan, who, as he did with his famous series Cosmos , it is important to share with the greatest number of scientific culture, scientific and rationalist mind that founds, and wonder at the spectacle of the laws of nature at work in astrophysics.
In 1995, in the Cassiopeia issue, André Brahic and his collaborator Cecilia Ferrari talk about the discovery of the rings of planets in the solar system. © Jean-Pierre Luminet
The Saturn’s rings to the rings of Neptune
In 1989 Voyager 2 will be photographed for the first time Neptune rings whose existence had been demonstrated in 1984 thanks to the star occultation observation program proposed by André Brahic and colleagues Bruno Sicardy and Françoise Roques Observatory of Paris-Meudon, and directed by Patrice Bouchet, Reinhold Hafner and John Manfroid at the La Silla Observatory (Eso). Confirmation was also given by the observations of F. Vilas and L.-R. Elicer, following a program conducted by Williams Hubbard. Neptune The five rings are named after astronomers who contributed important work on the planet namely Galle, Le Verrier, Lassell, Arago and Adams. In 1989 also, we discover Voyager with three arches in the last ring (Adams) who were baptized Liberty, Equality and Brotherhood . Cécile Ferrari discovered in fact that there was a fourth arc called from Courage , the “c” are told by reference to the French astronomer.
In June 1980, when Voyager 1 was about to arrive in the vicinity of Saturn, and the success already gained by traveling with the exploration of Jupiter, Andre Brahic and some of his colleagues already reflected in the next stage, that is to say, the orbit of a probe around Saturn, after Voyager overflights 1 and 2. However, not everyone is enthusiastic , thinking that the project is too ambitious and too costly.
André Brahic thus apostrophized his colleagues a little chilly, saying: “ in life, suffice it to say that something is impossible for her to become . ” It will still ten years for NASA and ESA agree to build the Cassini spacecraft to be launched in 1997. The mission itself will cost about $ 4 billion, that is, say almost as expensive as the LHC and will eventually continue until at least 2017, when André Brahic had much work in imaging of the Cassini mission team, allergic to the idea of taking his retirement. He would have seen elsewhere, still alive, as a member of a mission specifically dedicated to the study of Neptune and its rings in 2060.
Asked about the possibility of discovering extraterrestrial life in the near future, the great passion of Carl Sagan, André Brahic showed very cautious, but probably confident. “ To the question of whether extraterrestrial life exists, a scientist can answer that: I do not know and that’s why we seek! “and he insisted it is not really possible to make a prognosis he said. “ No doubt, if we soon discovered a real exoterre many ways would be implemented to detect a biosignature in the decades that follow. We could then expect a response before the end of the XXI th century “added the researcher. He had recently dedicated his latest book, Lands also class = “xt-click” fs: xt: ClickType = “S” fs:xt:clickname=”clic-content::actualite::62810::http://www-odilejacob-fr/catalogue/sciences/astronomie-astrophysique-cosmologie/terres-dailleurs_9782738131522-php” & Gt ;, this question together with astrophysicist Bradford Smith
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