Members of the Swedish Royal Society of Science have awarded the 2019 Nobel Prize in Physics for contributions to our understanding of the evolution of the universe and Earth’s place in the cosmos. The prize is to be jointly shared between Professor Jim Peebles for theoretical discoveries in physical cosmology, and Michel Mayor and Didier Queloz for the discovery of the first exoplanet orbiting a solar-type star.

Peebles' contributions to cosmology are profound. He was among those that predicted the existence of the cosmic microwave background and also worked on other aspects of the Big Bang Theory, like the formation of the first elements in the universe and dark matter.

The second half of the prize shifts our focus from understanding the fundamentals of the universe to observing the objects within our own galaxy. On October 6, 1995, just over 24 years ago, swiss astronomers Mayor and Queloz announced the discovery of a planet around the star 51 Pegasi.

The discovery was monumental for several reasons. It was the first discovery of an exoplanet around a main-sequence star; previous exoplanetary detections were around pulsars. It also went against the wisdom of the time on how planetary systems should behave.

Planet 51 Pegasi b has a mass of at least half of Jupiter but it orbits its star just 7.88 million kilometers (4.9 million miles) away. Astronomers didn’t think that gas giants could be found that close to their parent stars. Since then, among the 4,000+ discovered exoplanets, we have found many examples of these hot Jupiters orbiting very close to their stars.

This year's Physics Prize recognizes both aspects of theory and observation in science. As Professor Peebles said in the press conference announcing the Prize: “Theory is empty without observations. We depend on the interaction between the theory and observations.”

Given that today is Ada Lovelace Day, it would be remiss not to note that some of the barriers that have kept women and underrepresented groups from attaining long careers and accolades in scientific fields still exist in some places, and this will be reflected in awards marking life-long contributions to a field.  

Only three women have won the Nobel Prize in Physics: Marie Curie, Maria Goeppert-Mayer, and, last year Donna Strickland, meaning there are still fewer women than men named James that have won the award.