The planet K2-18b is located about 120 light-years away from Earth, in the direction of the constellation Leo. It orbits a ...

The Solar System does not have a clear border. The influence of the Sun in certain domains is small enough for the Voyager ...

Neptunes, exoplanets whose sizes are between Earth and Neptune, and which are between the known for their water-rich ...

Planet Nine was previously suggested as a possible explanation for distant orbital clustering. It was thought to be ten times Earth’s mass, orbiting far beyond Neptune.

According to the paper laying out the research behind the discovery, "TOI-1846b is a super-Earth-sized planet, with a radius of approximately 1.8R⊕, placing it within the intriguing radius valley area ...

New discoveries of objects in the Kuiper Belt have also presented challenges for the Planet Nine theory. The latest is known ...

When Scientific American published its very first issue 180 years ago this month, our view of the cosmos was substantively different. Closer to home, astronomers were wildly guessing about how our ...