Highly energetic and difficult to detect, neutrinos travel billions of light years before reaching our planet.
An international research team, led by the University of Würzburg and the University of Geneva (UNIGE), is shedding light on one aspect of this mystery:
Neutrinos are thought to be born in blazars, galactic nuclei fed by supermassive black holes.
The Earth's atmosphere is continuously bombarded by cosmic rays. These consist of electrically charged particles of energies up to 1020 electron volts.
The extremely energetic particles come from deep outer space, they have traveled billions of light years.
Where do they originate, what shoots them through the universe with such tremendous force?
Cosmic rays' birthplaces produce neutrinos. Neutrinos are neutral particles difficult to detect. They have almost no mass and hardly interact with matter.
They race through the universe and can travel through galaxies, planets and the human body almost without a trace.