RESEARCH HIGHLIGHTS

摘要

Dark matter is a hypothetical class of particles that interact mainly through the force of gravity. How much dark stuff might be lurking around Earth is the subject of some debate, but Stephen Adler at the Institute for Advanced Study in Princeton, New Jersey, has set an upper limit. Adler took data on the radius and period of a gravity-sensing satellite to estimate the planet s mass, including its dark matter, as well as lunar and asteroid orbital data to estimate the total mass inside the Moon's orbit.