You can name a crater on Mercury. NASA recently reported that the Mercury orbiter the MESSENGER located five of the impact craters over the last three years of its mission. The Mercury orbiter has been circling the planet since March 2011.
The orbiter arrived at Mercury following an 8billion mile trip after it was launched in 2004. It will run out of fuel sometime next year. NASA and the MESSENGER Education and Public Outreach program is holding a contest to name the above-mentioned five craters.