Belgian physicist Francis Halzen on Tuesday won the Nobel Prize in Physics for work on subatomic particles at the South Pole, the award jury said.

“This year’s prize is about ghostly messengers from space,” Ellen Moons, secretary general of the Royal Swedish Academy of Sciences, told a news conference.

Halzen was honoured “for decisive contributions to the IceCube Neutrino Observatory and the discovery of high-energy neutrinos of astrophysical origin”, the jury said.

The Royal Swedish Academy of Sciences noted that Halzen’s “vision and scientific leadership” had been fundamental for the observatory, which it described as “a cubic kilometre of ice that is equipped with light sensors”.

Using the observatory, researchers can capture neutrinos — rare subatomic particles — “from extremely energy-rich processes in the distant universe”.

“This Nobel Prize is about a giant ice cube positioned at the South Pole of our globe. The ice cube enables the detection of neutrinos,” professor Eva Olsson, a member of the Nobel Committee for Physics, told reporters.

Halzen, 82, was born in Tienen, Belgium and is a professor at the University of Wisconsin-Madison in the United States.

“It was a great surprise, and I obviously didn’t expect it,” he told the news conference by telephone shortly after the prize was announced.

“But it’s a great pleasure to hear about this prize,” Halzen said.

The award is the second Nobel of the season, after the Medicine Prize was awarded on Monday to US psychiatrist and neurologist Karl Deisseroth and German scientists Peter Hegemann and Georg Nagel.

The researchers were honoured for their pioneering work in the field of optogenetics, which involves controlling nerve signals with light.

Peace prize lobbying

Last year, the Nobel Prize in Physics went to Briton John Clarke, Frenchman Michel Devoret and American John Martinis for putting quantum mechanics into action and enabling the development of all kinds of digital technology from cellphones to a new generation of computers.

The physics prize will be followed by the chemistry one on Wednesday.

The literature laureate will be revealed on Thursday, with some pundits suggesting that the Swedish Academy could follow up last year’s award to Hungary’s Laszlo Krasznahorkai with a woman writer, possibly from Latin America.

The perhaps most keenly anticipated award — the peace prize — is due on Friday.

US President Donald Trump lobbied intensively last year to get the prize — and Venezuelan opposition leader Maria Corina Machado ended up giving him her Nobel medal — and the committee is aware he will be watching closely again.

The economics prize wraps up the Nobel season on October 12.

The Nobel consists of a diploma, a gold medal and a 12-million-kronor ($1.2 million) prize sum, which is shared if there is more than one winner in a discipline.

The laureates will receive their prizes at a formal ceremony on December 10, the anniversary of the death in 1896 of scientist Alfred Nobel, who created the prizes in his will.