At the end of a lecture on astronomy, describing how the planets orbit the Sun, a little old lady at the back of the room ...

Nilakshi Veerabathina does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations ...

“Dark energy” is a term scientists use to refer to whatever is causing the universe to expand faster over time. We don’t know exactly what dark energy is—no one has ever directly seen or measured ...

A simple explanation of dark matter and antimatter, how they differ, how scientists study them, and why both are important to understanding the universe.