New data and photos challenge previous theories on Mars' moon Deimos.

The United Arab Emirates released new images and data of Mars' smaller moon, Deimos, challenging the long-standing theory that the moons are asteroids trapped in the planet's orbit. The images suggest that Deimos is composed of dark, volcanic rock consistent with the Red Planet's composition, indicating that both moons may have formed from leftover debris after something struck Mars. The findings were unveiled during a special session at the European Geosciences Union General Assembly in Vienna.