A new study suggests yet another theory for a possible extra planet in our solar system, likely of a size between Mercury and ...

The bold question-askers at What If examine what life would be like if Earth were the only planet in the solar system.

From tentative evidence of habitable planets to the eyebrow-raising suggestion an interstellar comet might not be what it ...

Astronomers have been fascinated after spotting an object earlier this year that came from interstellar space as is now hurtling through our inner solar system. Regardless, it’s an interesting visitor ...

The official number of planets outside our solar system has reached 6,000, according to space scientists. Get any of our free email newsletters — news headlines, sports, arts & entertainment, state ...

The official number of planets outside our solar system has reached 6,000, according to space scientists. NASA's tally of exoplanets does not include more than 8,000 additional candidate planets ...

Astronomers using the Hubble Space Telescope have observed a white dwarf - a highly compact stellar ember - that appears to ...

Astronomers have directly spotted a rare young planet, WISPIT 2b, still forming within the gap of a dusty ringed disk around a star like our sun—something long theorized but never observed until now.

It's much harder to find, but there are a lot more of them." The first interstellar object to visit the solar system may have ...