Gravity Anomaly Challenges MESSENGER Mission

Universe Today reported Gravity Anomaly Challenges MESSENGER Mission:

"Scientists from the MESSENGER mission continue to analyze the data from the spacecraft's first flyby of Mercury on January 14, 2008. Initial data about the planet's gravity field grabbed the science team's attention, as the actual gravity data differed from predictions based on the Mariner 10 flyby in 1975."

"The new data about Mercury's internal structure is different from what the scientists expected. McNutt said that while it was surprising that the tracking data did not fit all of their preconceived notions from Mariner 10, MESSENGER went much closer to Mercury than did Mariner, which could account for the differences in data. Scientists believe there may be a large concentration of mass (mascons) under Mercury's surface about 10 degrees south of the equator at about 60 degrees longitude. A presentation by team member David Smith at the Lunar and Planetary conference in March showed that they were able to account for about 95% of the problem deviation using a single mass anomaly at that location."