Planetary size was determined pre-spacecraft by measuring the planet's angular diameter and its distance from Earth (in AU, later converted to terrestrial units after the AU was accurately measured ...

Planets may begin forming much earlier than scientists once believed during the final stages of a star s birth, not afterward. This bold new model, backed by simulations from researchers at SwRI, ...

As many as 200 worlds beyond our solar system discovered by astronomers may be larger than estimated, which could influence the search for extraterrestrial life. That's the theory of a team of ...