Is there a massive undiscovered planet on the outer reaches of the solar system? The idea has been around since before the ...

Farther out, between 90 and 105 astronomical units, the water-ice mass fraction rises to 7.5%, and between 105 and 120 astronomical units it peaks at 21%, out where it is coldest.

Astronomers have discovered "Ammonite," a mysterious object on the solar system’s edge whose unusual orbit challenges current ...

A newly found icy object, Ammonite, may be a 4-billion-year-old fossil from the Solar System’s edge—and it’s casting doubt on the Planet Nine theory.

Recent exquisite images from the James Webb Space Telescope had revealed several concentric arcs just beyond the outer edge of the main ring, which seem to have formed every 280 years.

Astronomers using the Subaru Telescope have discovered a strange new body in a weird orbit at the edge of the solar system, which could be bad news for Planet Nine theories.

The first ever space telescope, the Orbiting Astronomical Observatory 2 (OAO-2), was launched into the low Earth orbit in 1968 aboard an Atlas-Centaur rocket, as per the National Space Centre.