This instrument is what’s known as a Faraday cup, a sensor designed to measure the ion and electron fluxes and flow angles from the solar wind.

Far from being an empty void, the space around Earth is a jungle of invisible fields and tiny particles. It’s draped with twisted magnetic field lines and swooping electrons and ions.

A cation is a positively charged ion, with more protons than electrons, while an anion is negatively charged, with more electrons than protons.

I want to ask you something, Ms. Ionescu.

Mercuric nitrate is an ionic compound.

Mrs. Ionescu, I'd like to ask you something.

Positive ions are called cations.

What's an ionic bond?

What is an ionic bond?

This spacecraft is powered by ion thrusters.