Astronomers have been searching for evidence that Planet Nine exists for years Researchers have found more evidence that there is an unknown planet in our solar system. Astronomers have been ...

The concept of Planet X, or Planet Nine, has captivated astronomers for decades. This hypothetical planet, theorized to be ...

The possibility that there might be a large, unknown planet lurking in the outer Solar System far beyond Pluto has long been a staple of science fiction. But for the past decade, astronomers have been ...

Watch this video to find out more about the Earth, planets in our Solar System and other planets far off in outer space. From up here on the International Space Station I get a great view of Earth.

Through observations, either with space telescopes or with ground-based equipment, we can find out how planets in our solar system and beyond are structured, what materials they are made of, whether ...

The orbits of the planets in our solar system are chaotic, says Portegies Zwart. As a consequence of long-term orbital resonance interactions with Venus and Jupiter, Mercury stands about a 5 ...

However, exactly how that happens for a multi-planet star system — like our solar system — is unknown. The paper, published today in The Astrophysical Journal Letters, details observations of ...

A planet parade is when several of our solar system's planets are visible in the night sky at the same time. There will be six planets visible this time around, including Venus, Mars ...