When you buy through links on our articles, Future and its syndication partners may earn a commission. A newly proposed mass-based definition of a planet classifies thousands of exoplanets across the ...

When you buy through links on our articles, Future and its syndication partners may earn a commission. Three astronomers last week proposed expanding the official definition of a planet to encompass ...

Three astronomers last week proposed expanding the official definition of a planet to encompass worlds orbiting stars other than our own, a nuance not currently included in the formal definition of ...