After carefully measuring the masses of small, rocky exoplanets, astronomers have come to the conclusion that our solar system may not be unique and, by extension, those exoplanets surveyed are likely composed of similar materials as Earth.

Using the High-Accuracy Radial velocity Planet Searcher (HARPS) North instrument on the 3.6-meter Telescopio Nazionale Galileo in the Canary Islands, the researchers, led by Courtney Dressing of the Harvard-Smithsonian Center for Astrophysics (CfA), focused on the slight wobble small exoplanets exert on their host stars.