The potential discovery of a large planet beyond Neptune’s orbit could change everything we know about the Solar System.

Growing up, I was taught that there were nine planets in the solar system. That all changed in 2006, when the International ...

A powerful new tool comes online this year that could help astronomers locate the mysterious planet hiding somewhere beyond ...

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

The six planets will be visible in the days immediately leading up to Jan. 21, and for about four weeks afterward. Mars, ...

A six-planet alignment or parade will form an arc in the early night sky, peaking in it's visibility Jan. 17-18. We let you ...

The solar system may hold a hidden surprise. Astronomers are investigating the possibility of a mysterious ninth planet, often referred to as Planet Nine. If found, this discovery could change the ...

21. 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 ...

The solar system consists of 8 planets, including Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Each planet has its own unique characteristics, such as size, composition ...