Scientists can use many different kinds of materials to detect neutrinos, from mineral oil and dry cleaning fluid to Antarctic ice and water. Because neutrinos are neutral and so small, it is impossible to detect them directly. Instead, all techniques rely on detecting the heavier, charged particles generated when a neutrino interacts, creating a signature track, flash of light, line of bubbles, change in temperature, or other indicator, depending on the material. Because neutrinos interact so rarely, detectors need to be very big and experiments need to run for long periods to take a lot of data. They must also have systems in place to weed out interactions from other particles that could clutter up neutrino data.