New simulations suggest that up to four of the solar system's rocky planets, including Earth and a long-lost world, once ...

In our solar system, Mercury, Venus, Earth, and Mars have period ratios of about 2.6, 1.6, and 1.9, respectively. Overall, the study showed that our solar system fits reasonably well into the team ...

Scientists have thought that our solar system's inner rocky planets — Mercury, Venus, Earth and Mars —formed first (around 4.566 billion years ago), while gas giants and icy bodies in the ...

This mismatch “doesn’t mean it’s not there, but it means it’s not Planet 9,” Brown said. “I don’t think this planet would have any of the effects on the solar system that we think we ...

Astronomers have discovered that the largest comet from the Oort Cloud, a shell of icy bodies at the very edge of the solar system, is bursting with chemical activity. Using the Atacama Large ...

For only the third time in history, astronomers have discovered a new interstellar object that originated from outside our Solar System. The object, known as 3I/ATLAS, is likely a comet and is ...

It Came From Outside Our Solar System, and It Looks Like a Comet 3I/ATLAS, earlier known as A11pI3Z, is only the third interstellar visitor to be discovered passing through our corner of the galaxy.

A comet from a solar system outside our own was first noticed on July 1 by a NASA telescope located in Rio Hurtado, Chile, as part of the Asteroid Terrestrial-impact Last Alert System (ATLAS).