This week, an old astronomical controversy is renewed as researchers present new evidence for a hidden "Planet X" in our solar system.

Today, it’s believed that Jupiter and Saturn, the largest planets, were the first to fully form, both within a few million years. Uranus and Neptune were next, within 10 million years. The inner ...

Our solar system may have a ninth planet after all, following the declassification of Pluto nearly two decades ago, ...

Astronomers have found new evidence that a mysterious ninth planet may be hiding at the edge of the solar system - rewriting what we know about the cosmos again. An international team from Taiwan ...

Discover the order of planets in the solar system. From Mercury to Neptune, explore our solar system and learn more about our cosmic home. The solar system is our cosmic neighborhood, made up of ...

Mar. 17, 2025 — A combination of cosmic processes shapes the formation of one of the most common types of planets outside of our solar system, according to a new ... Webb Telescope Captures Its ...

Astronomers claim to have discovered a new ninth planet in our Solar System. Planet Nine, also known as Planet X, is a hypothetical celestial object that would distantly orbit our Sun – but ...

The hunt for Planet Nine—the solar system’s ghostly gravitational troll—is longstanding, and is based on the peculiar clustering of rocky bodies in the Kuiper Belt beyond the orbit of Neptune.

Indeed, other planets, dwarf planets and moons in our solar system do have seasonal cycles — and they can look wildly different from the ones we experience on Earth, experts told Live Science.

And these observations are giving us hints about what's going on? A new "Tatooine-like" planet outside the solar system may orbit two failed stars, scientists reported Wednesday.Related video ...

Once the quirky underdog of our solar system, Pluto held planetary status until 2006, when it got a cosmic demotion that still stings space fans. Discovered in 1930, Pluto was the ninth planet for ...