This year's Nobel Prize in Physics went to research that found the universe's 'ghost particles' in Antarctic ice. The Royal Swedish Academy of Sciences on Oct. 6 (local time) named Francis Halzen, a professor at the University of Wisconsin-Madison. Wire reports said decades of work at the South Pole opened the way to a 'new kind of astronomy.'

Neutrinos have almost no mass and no charge and pass through nearly all matter, so they are often called 'ghost particles.' High-energy neutrinos from extreme objects such as exploding stars and black holes carry information from distant parts of the universe intact, but they are known to be extremely hard to detect.

A cubic kilometer of ice as a detector

The IceCube Neutrino Observatory that Halzen led turns about a cubic kilometer of deep ice near the South Pole into a detector. Thousands of light sensors are buried in the ice to catch the faint blue light emitted when a neutrino collides with it.

After first confirming high-energy neutrinos from space in 2013, the observatory in 2017 linked the arrival direction of a neutrino to a blazar at the center of a distant galaxy, offering a clue to the origin of cosmic rays. Such results are credited with pioneering 'neutrino astronomy,' seeing the universe through neutrinos.

Meaning and open questions

Neutrinos can pass through regions of the universe that light and radio waves cannot. Research using the particle to unlock the secrets of extreme cosmic phenomena is expected to expand, and follow-on observation projects with researchers from many countries, including Korea, are continuing.

After the physics prize on Oct. 6, the chemistry prize is announced on the 7th, followed in turn by literature, peace and economics.