The relative size of the inner planets of our solar system: Mercury, Venus, Earth and Mars. Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert!

A powerful new observatory is the best hope yet for finding the elusive Planet 9, a large planet that some scientists say is hidden in our solar system.

The James Webb Space Telescope has captured its first direct images ... pretty big implications," Balmer said. "If you have these huge planets acting like bowling balls running through your solar ...