A new dwarf planet, discovered beyond Neptune and described as Pluto's 'cousin,' could void the hypothesis of a Planet X in ...

Around 16-17 June, Mars will appear to pass close to Regulus, the bright star at the heart of the constellation Leo, the lion ...

As NASA rolls out more powerful telescopes in the future, scientists will need a way to determine where to point them. A new ...

U.S. astronomers hunting for "Planet Nine" have instead stumbled on what appears to be a new dwarf planet in the solar system ...

Today, it’s believed that Jupiter and Saturn, the largest planets, were the first to fully form, both within a few million ...

An alternate explanation that fits the evidence is that Vesta was once part of a planet – but which planet that might been remains a mystery.

It is an evocative idea: a huge and mysterious planet is lurking in the darkness at the edge of our solar system, evading all ...

There’s a new frozen oddball orbiting the Sun, and it’s not your average space rock. It’s a planet—a minor one, to be ...

The universe is soaked in weak-but-persistent magnetic fields. Despite decades of research, astronomers still aren't exactly ...

Dozens of NASA's missions to explore the cosmos could be in jeopardy under a budget proposal from the Trump administration.

For decades, our solar system was thought to have nine planets, with Pluto considered the smallest and farthest. But in 2006, ...

A US-based trio hunting "Planet Nine" has instead stumbled on what appears to be a new dwarf planet in the solar system's ...