An $18-million joint Japanese-United States project to research cosmic rays was slated for groundbreaking on Saturday in the desert state of Utah.
The Japanese government is contributing $12-million to the project, which involves building three hilltop ”fluorescence” detectors and another 576 smaller detectors scattered over a 1 000 square kilometre area.
Cosmic rays, first discovered in 1912, are subatomic particles with ultra-high energy that rain onto Earth from outer space, but the exact source of the rays is unexplained.
The rays are ”100-million times more energetic than anything produced by particle smashers on Earth”, a University of Utah press statement said. The university is a pioneer in cosmic ray research, benefitting from the clear dry air of the US Southwest.
”We don’t know where they are coming from,” said Pierre Sokolsky, the university’s physics chairperson. ”We don’t know why they are here. This groundbreaking is a guarantee there will be tremendous new data to shed light on this mystery.”
The joint US-Japan project, called Telescope Array, centres on three larger detectors to be built atop Black Rock Mesa, site of the groundbreaking, and two other hilltops. Each detector will contain 12 sets of mirrors to register faint blue flashes in the night sky caused when cosmic rays collide with atmospheric gas
molecules.
The 576 smaller ”scintillation” detectors scattered through the region will be mounted on tables less than a metre high to measure ”air showers” of subatomic particles that reach the ground after the collisions.
Scientists have theorised that cosmic rays come from noisy radio galaxies, supermassive black holes, shock waves from colliding galaxies or even from the decay of massive particles left over from the ”big bang” that scientists believe formed the universe about 13-billion years ago, the press statement said. ‒ Sapa-DPA