Neutrinos are elementary particles that interact via the weak interaction force and gravity.

The neutrino is so named because it is electrically neutral and because its rest mass is so small that it was once thought to be zero.

They belong to the family of leptons, alongside electrons and muons.

Neutrinos are produced in vast quantities by nuclear reactions, such as those inside the Sun, exploding supernovae, and even nuclear reactors on Earth.

Their defining characteristic is that they barely interact with matter. Billions of them pass through your body every second without any notable effect.

Their elusive ghostly nature makes them very challenging to study. To detect them, Earth-based observatories use massive underground tanks and sensors, filled with ultra-pure water or ice to catch the occasional interaction.

Neutrinos come in three types, or “flavours”:

They have a fascinating ability called neutrino oscillation, where they spontaneously change between flavours as they travel through space – a process that hints at their tiny but nonzero mass.