Astronomers have identified a small but significant possibility that a Neptune-sized planet is quietly orbiting within the distant Oort cloud, the icy boundary of our solar system. According to recent ...

Breakthroughs, discoveries, and DIY tips sent every weekday. Terms of Service and Privacy Policy. You probably learned growing up there are nine planets around the ...

Astronomers searching for the faintest glimmers of light beyond distant Pluto say they’ve discovered a new dwarf planet – and that this planetoid’s movements hint that an invisible giant planet ...

In 1906, astronomer and businessman Percival Lowell launched a search for "Planet X," a hypothetical giant planet orbiting the sun beyond Neptune. Lowell was convinced that Planet X existed based on ...

The human mind may find it difficult to conceptualize: a cosmic cloud so colossal it surrounds the Sun and eight planets as it extends trillions of miles into deep space. The spherical shell known as ...