Nobel Prize: Recognizing the 1995 discovery of the first exoplanet

Twenty-four years ago, an unassuming Swiss astrophysicist named Michel Mayor took the floor at a conference in Florence, Italy, to announce the discovery of an exoplanet — a planet orbiting a sun-like star far beyond the solar system.

The existence of such worlds had long been theorized but never confirmed, until Mayor’s remarks October 6, 1995, at the Ninth Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, in Florence.

Almost to the day 24 years later, Mayor and his former student, Didier Queloz, were awarded the Nobel Prize in Physics, an honor shared with James Peebles of Princeton University.

The discovery by Mayor, then a professor at the University of Geneva in Switzerland, and Queloz, who in 1995 was a PhD student working with Mayor, was a major development in a watershed year.

As I wrote in my book, 1995: The Year the Future Began, their discovery “represented an essential if tentative step in the long-odds search for extra-solar intelligent life.”

Since 1995, the existence of more than 4,000 other exoplanets has been confirmed, including a strange world that orbits two stars, not unlike “Tatooine” in Star Wars. This circumbinary planet was discovered by NASA’s Kepler space telescope in 2011.

The first exoplanet was rather inelegantly christened “51 Pegasi b.” It’s also called “Dimidium.”

It is, as I wrote in 1995, “a blasted, gaseous world far larger than Jupiter that needs only 4.2 Earth days to orbit its host star in Pegasus, the constellation of the winged horse. It is an inhospitable, almost unimaginable world. The planet’s dayside — the side always facing the host star — has been estimated to be 400 times brighter than desert dunes on Earth on a midsummer’s day. Its nightside probably glows red.”

Detecting and confirming the existence of such a world began “a revolution in astronomy,” the Nobel committee noted in its statement announcing this year’s winners in physics.

The detection of exoplanets, the committee added, has challenged “preconceived ideas about planetary systems” and have forced “scientists to revise their theories of the physical processes behind the origins of planets.”

Mayor (Photo by Ann-Marie C. Regan)

Mayor and Queloz’s discovery of 51 Pegasi b — a huge planet orbiting near its host star — posed a clear challenge to what in 1995 was the dominant theory of planetary formation. It was thought that a giant planet could not long survive the extraordinarily high temperatures and other effects of being so close to its host.

“Most people were skeptical” when Mayor announced the discovery in October 1995, Queloz has said. “The expectation was to find giant planets in long period orbit [that took years, as] in our solar system — we had challenged that paradigm.”

Three months before then, Mayor and Queloz had confirmed the existence of the exoplanet to their satisfaction, in observations at the Observatoire de Haute Provence in France. The discovery, Mayor said in an interview in 2011, was akin to “a spiritual moment.”

WJC

More from The 1995 Blog:

• Exoplanet discovery a memorable first in 1995
• Of space shuttles and love-sick woodpeckers,1995
• Recalling the ‘coolness’ of the early Web
• Media fail: A 1995 subtext that’s familiar today
• ‘Cyberporn’ scare of 1995 demonstrates the early Web’s corrective power
• When Secret Service agents wore gloves to greet gay officials
• The ‘Internet Tidal Wave,’ 20 years on
  
• Talking Internet history, and 1995
• Talking 1995
• The 1995 Blog turns five: A look back at five top posts