A new study has proposed the existence of Planet Y, an alternative Planet Nine candidate that is smaller and closer to Earth ...

There are a couple of ways that scientists can date planets, so which planets formed first in our solar system?

The European Space Agency also hoped to observe the interstellar object during its close approach to Mars using two ...

Interstellar comet 3I/ATLAS has caught the interest of astronomers and amateur enthusiasts alike as just the third object to ...

We all need some space sometimes—but it's harder to find than you might think. How far into our universe do we have to go to ...

A new study suggests yet another theory for a possible extra planet in our solar system, likely of a size between Mercury and ...

Astronomers have discovered a distant dwarf planet orbiting beyond Neptune — a frozen world so far from the Sun that it ...

Our solar system is a smashing success. A new study suggests that from its earliest period—even before the last of its ...

From lava worlds to gas giants, NASA says the variety of these worlds is staggering—and that signs of a further 8,000 distant ...

The solar system is a grand cosmic stage where each planet and moon plays a unique role in a story billions of years in the making. From Mercury’s shrinking surface and Venus’s runaway greenhouse ...

After decades of exploring, NASA's Voyager 1 hit the edge of the solar system and passed through a great "wall of fire," ...

A mysterious space object named 2023 KQ14, nicknamed “Ammonite,” challenges theories about the mysterious and possible Planet ...