U.S. probe finds water ice in Mercury

U.S. space agency Nasa announced Thursday that its Messenger probe has discovered new evidence of water ice on Mercury, feeding the idea that deposits in permanently shadowed regions of Mercury's poles is water ice. According to a press release of the agency, the tilt of Mercury’s rotational axis is almost zero - less than one degree - so there are pockets at the planet’s poles that never see sunlight.

Launched in August 2004, the robotic spacecraft conducted three flybys of Mercury in 2008 and 2009 before entering the planet's orbit in March 2011. So far, the probe has collected more than 100,000 images of Mercury. Mission objectives of the Messenger probe include studying the nature of Mercury's magnetic fields, the structure of its core, its geologic history and the composition of its exosphere.