(Image credit: NASA/JPL-Caltech/University of Arizona) Scientists revisiting a mysterious signal from the south pole of Mars have suggested a new potential explanation, and it doesn't bode well for hopes of finding liquid water on the Red Planet.

A subatomic particle has been found to switch between matter and antimatter, according to Oxford physicists analyzing data from the Large Hadron Collider. It turns out that an unfathomably tiny weight difference between two particles could have saved the universe from annihilation soon after it...