A trio of scientists will share 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 Royal Swedish Academy of Sciences announced on Tuesday.

Half of the $1.1m prize went to James Peebles, a dual citizen of Canada and the United States, “for theoretical discoveries in physical cosmology” over the past 20 years that have enriched modern astronomy’s timeline of the universe, from the Big Bang onwards.

Peebles’ breakthroughs centred on the “ancient radiation” that originated during the Big Bang 14 billion years ago and continues to surround us.

“The results showed us a universe in which just five percent of its content is known, the matter which constitutes stars, planets, trees – and us,” the academy said in a statement. “The rest, 95 percent, is unknown dark matter and dark energy. This is a mystery and a challenge to modern physics.”

The other half of the prize was awarded jointly to Swiss scientists Michel Mayor and Didier Queloz “for the discovery of an exoplanet orbiting a solar-type star”.

Mayor and Queloz announced the first discovery of a planet outside the solar system in October 1995, a success the academy said kicked off “a revolution in astronomy”, with more than 4,000 exoplanets having since been found.

“This changed the way we think planets must have formed … the way that structures form, the way that planets formed, and perhaps even the way that life itself develops,” Christopher Conselice, professor of astrophysics at the University of Nottingham, told Al Jazeera.

The “love of science” should be the driving force for young researchers going into science, not the search for awards, said Canadian-born US researcher Peebles of Princeton University.

Peebles was speaking over the phone on Tuesday to reporters at the Royal Swedish Academy of Sciences, minutes after learning of his Nobel win.

Both Mayor and Queloz are from the University of Geneva. Queloz is also associated with the University of Cambridge, in the United Kingdom, where he is the professor of astrophysics at the Cavendish laboratory.

The Nobel committee said the work of the three scientists “painted a picture of the universe far stranger and more wonderful than we ever could have imagined”.