Artist impression of the planetary system with four planets,around a small red star,called LHS1903. Caption: Astronomers have long thought solar systems follow a simple pattern similar to our own: ...

We know that our Solar System is not the blueprint for all planetary systems out there. There are gas giant planets orbiting closer to their stars than Mercury, and rocky worlds much larger than Earth ...

Astronomers have found a distant world that challenges planetary formation theory, with a rocky planet where gas giants should be.

A closer look at the planets around a star called LHS 1903 may just flip our understanding of how planetary systems form.

A planetary system 116 light-years from Earth has a peculiar pattern. It could flip the script on how planets form, scientists say.

Since the 1990s, scientists have discovered approximately 6,100 planets outside our solar system, called exoplanets.

Typically, from what astronomers have gathered thus far, star systems follow a tidy logic: small, rocky worlds huddle close to the warmth of their star, while massive gas giants bloat up in the colder ...

Gas giants possibly developed slowly in the solar system. They developed cores layer by layer within a disk of ice and dust ...

Gas giants are large planets mostly composed of helium and/or hydrogen. Although these planets have dense cores, they don't ...

An unmanned spacecraft with ties to Tucson is on track to coast around the sun this winter before sling-shotting by Mars on its way to a rendezvous with an asteroid and a dwarf planet. NASA officials ...