Curious Kids^[1] is a series for children of all ages. If you have a question you’d like an expert to answer, send it to This email address is being protected from spambots. You need JavaScript enabled to view it.^[2]. How does soap clean our bodies? – Charlie H., age 8, Stamford, Connecticut Thousands of years ago, our ancestors discovered something that would clean their bodies and clothes.

Is your green my green^[1]? Probably not. What appears as pure green to me will likely look a bit yellowish or blueish to you. This is because visual systems vary from person to person. Moreover, an object’s color may appear differently^[2] against different backgrounds or under different lighting.

These facts might naturally lead you to...

The detection of life beyond Earth would be one of the most profound discoveries in the history of science. The Milky Way galaxy alone hosts hundreds of millions of potentially habitable planets^[1]. Astronomers are using powerful space telescopes^[2] to look for molecular indicators of biology in the atmospheres of the most Earth-like of these...