What is the main idea of the passage?

Neutrinos rarely interact with matter, so scientists use enormous protected detectors to capture enough rare collisions to study them. (The passage links the neutrino’s weak interaction to both its value as a messenger and the need for very large detectors.)

Why are neutrinos able to carry relatively direct information from the solar core?

They can leave the core without repeatedly colliding with charged matter. (The text contrasts neutrinos with light, which may repeatedly meet charged particles before it escapes the Sun.)

In the phrase “That indifference makes neutrinos valuable messengers,” what does “indifference” mean?

their tendency to pass through matter with almost no interaction (Here “indifference” describes neutrinos behaving as though most surrounding matter were not there.)

What is one purpose of placing some neutrino detectors deep underground?

to screen out more common particles that could confuse the measurement (The passage states that underground placement screens out more common particles, making rare neutrino signals easier to identify.)

The Particle That Passes Through Earth: Level 5 Reading Comprehension Questions

Every second, enormous numbers of neutrinos pass through your body and continue through Earth. They arrive from the Sun, from exploding stars, and from reactions high in the atmosphere. Yet you do not feel them. A neutrino has no electric charge and interacts with ordinary matter through forces that act only at extremely short range. Most neutrinos cross atoms without disturbing them.

That indifference makes neutrinos valuable messengers and difficult objects to study. Light from the center of the Sun may take a very long time to work outward, repeatedly meeting charged particles. Neutrinos leave almost immediately, carrying information about reactions in the solar core. However, the same weak interaction that lets them escape also lets them pass unnoticed through a laboratory.

Researchers answer this problem with scale and patience. Some detectors use huge tanks of water or other clear materials, placed deep underground to screen out more common particles. On rare occasions, a neutrino strikes a particle in the tank. The collision produces a faint pattern of light that sensitive instruments record. Scientists then compare many such flashes, their directions, and their energies. No single flash tells the whole story. Evidence emerges from a large collection of unlikely events. A neutrino detector therefore works by accepting an apparent contradiction: to observe particles that barely touch matter, researchers give them an immense amount of matter to cross.

Comprehension questions