Mercury is Smoother Than the Moon, and Other New Surprises From the Innermost Planet
Detail: Mercury North Latitudes New observations from the Messenger spacecraft suggest a deep reservoir of high-density material exists within Mercury. Measurements show that Mercury must have sustained intense geophysical activity for most of its history, scientists say. Future observations will help answer some questions about how this material formed. NASA/JHUAPL/CIW-DTM/GSFC/MIT/Brown University. Rendering by James Dickson and Jim Head NASA's Messenger spacecraft entered orbit around Mercury one year ago this week, and the spacecraft has been hard at work. It has captured nearly 100,000 images, mapped Mercury's gravity field, and taken sensitive altimetry measurements that are shedding light on the planet's surface features like never before. This week, scientists on the Messenger mission published another round of new findings about the innermost planet, which turns out to be an altogether weirder world than we'd thought. Click to launch the photo gallery The planet's crust is thicker in low latitudes and thinner at the poles,...