A new study has proposed the existence of Planet Y, an alternative Planet Nine candidate that is smaller and closer to Earth ...

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

From lava worlds to gas giants, NASA says the variety of these worlds is staggering—and that signs of a further 8,000 distant ...

Since Pluto was relegated to dwarf planet status, almost everyone has agreed that there are eight planets in our solar system ...

What makes a planet a planet? And what makes a star a star? Once we know this these defining characteristics, we start to notice that these definitions can overlap. Which begs the question, can a ...

Saturn is known for its iconic rings, but it should also probably be known for its moons. The ringed world was already the record holder for the most natural satellites of any planet in the Solar ...

On October 6 1995, at a scientific meeting in Florence, Italy, two Swiss astronomers made an announcement that would transform our understanding of the universe beyond our solar system. Michel Mayor ...

Astronomers have identified an enormous "growth spurt" in a so-called rogue planet. Unlike the planets in our solar system, ...

Astronomers believe they may have found a brand new planetary neighbor in our own solar system — Planet Y. Though we haven’t ...

Planets that orbit white dwarf stars should be too hot to host alien life, theories suggest. But a new study accounting for ...

A mysterious space object named 2023 KQ14, nicknamed “Ammonite,” challenges theories about the mysterious and possible Planet ...

Scientists have discovered new information about the interstellar object nearing Earth which could reveal facts about the solar system it came from.