In the icy, dark expanse beyond Neptune, a cosmic fossil has surfaced that threatens to upset decades-old assumptions about the solar system’s secret structure. The new discovery of “Ammonite,” a ...

Scientists may have discovered a dwarf planet far beyond Neptune — an unearthing that may disprove a longstanding theory about the possibility of a giant ninth planet. The dwarf planet's existence ...

The Size and Orbit of 2017 OF201. The newly discovered object, 2017 OF201, has a diameter of 435 miles (700 kilometers), making it smaller than Pluto, which measures around 1,477 miles (2,377 ...

A telescope has discovered a new world on the edge of the Milky Way – potentially confirming the ‘Planet X’ theory. Beyond ...

2017 OF201’s elongated orbit makes it an outlier from the clustered objects, but Yang’s calculations suggest that the orbit of 2017 OF201 should remain stable over roughly the next billion years.

The mass of 2017 OF201 is estimated to be about 20,000 times smaller than Earth’s and 50 times smaller than Pluto’s. “We don’t know the shape yet.

The mass of 2017 OF201 is estimated to be about 20,000 times smaller than Earth's and 50 times smaller than Pluto's. "We don't know the shape yet. Unfortunately, ...

2017 OF201's extreme orbit makes it detectable about 1% of the time, the researchers said. Spotting 2017 OF201 beyond the Kuiper Belt, a donut-shaped section of space past the orbit of Neptune ...

They said: ‘The discovery of 2017 OF201 is significant because it’s found in a region of the Solar System thought to be empty, and it’s presence points to the existence of other similar ...

Named 2017 OF201, the new object is roughly 700km across according to a preprint study, which has not been peer-reviewed, published online last week. That makes it three times smaller than Pluto.

The potential planet, which has been temporarily called 2017 OF201, takes "more than 24,000 years to travel around the sun just once along a highly elliptical orbit, coming as close as 4.2 billion ...