Explores the possibility of the existence of other Earths, and explains how scientists use telescopes to look for other Earths. Includes color photographs, fact boxes, a glossary, and additional resources.

"Investigate!"

So much to discover -- Luck and skill -- Using what we know -- What to look for -- Finding the right spot -- Hard to find -- What can direct imaging tell us? -- Looking indirectly -- A happy accident -- Other Jupiters -- Space telescopes -- Still looking.