sometimes dipping close to Neptune's orbit, and sometimes swinging farther away. "That turns out to be another natural consequence of Planet Nine," Brown says. "We didn't think about it at the ...

If Planet Nine does exist, scientists believe it is ... a potential dwarf planet beyond the Kuiper Belt, had an unusual orbit ...

The number of planets that orbit the sun depends on what you mean by “planet,” and that’s not so easy to define ...

The agency announced on Monday afternoon (Feb. 10) that it has picked SpaceX to launch Pandora, a 716-pound (325-kilogram) ...

Known as Planet Nine or Planet X, it is a hypothetical planet ... the BBC as a "doughnut shaped region of icy bodies" beyond the orbit of Neptune – that had unusually warped orbits around ...

Stargazers will be treated to a rare seven-planet alignment in February. This is what scientists hope to learn.

The Planet Nine theory was based on several trans-Neptunian ... it would be expected that objects that developed in the circumstellar disk would orbit around the Sun on a more or less flat plane ...

Researchers have discovered an Earth-like planet with such an eccentric orbit that it swoops in and out of its habitable zone throughout its year. Though the super-Earth could theoretically be ...

The two planets are farthest apart when they are ... it would take about one and a half years to complete the elliptical orbit. "In the nine months it takes to get to Mars, Mars moves a ...