Early Earth may not have had the right ingredients for life — until a nearby Mars-size planet crashed into it, two new studies hint.

NASA's James Webb Space Telescope has made its first observations of interstellar comet 3I/ATLAS, revealing that the comet appears to be unusually rich in carbon dioxide.

The solar system has many more moons than the one we can see in the sky. But how many do we actually know about? And how many more are waiting to be discovered?

Uranus' 29th moon was hidden inside the planet's dark inner rings, new observations from the James Webb Space Telescope reveal.

New images from the Hubble telescope show an extrasolar entity as it hurtles through our solar system at speeds of more than 130,000 mph (210,000 km/h).

New simulations suggest that up to four of the solar system's rocky planets, including Earth and a long-lost world, once orbited in mathematical harmony around the infant sun.

The debate about an undiscovered Planet X or Planet Nine has been going on for more than 100 years.

Analysis of an ancient meteorite suggests that rocky planets both near and distant from the sun may have formed at the same time, challenging current models of our solar system’s evolution.

A newly discovered dwarf planet called 'Ammonite' (2023 KQ14) has been spotted in the outer solar system, and it could be another nail in the coffin for the Planet Nine hypothesis.

Scientists have found that Uranus emits its own internal heat, contradicting data from NASA's Voyager 2 probe nearly four decades ago.