2040 before we finally land. why is that? it depends on where - 2040 before we finally land. why is that? it depends on where you i that? it depends on where you are auoin back that? it depends on where you are going backfor that? it depends on where you are going back for mercury that? it depends on where you are going back for mercury there i that? it depends on where you are going back for mercury there are l going back for mercury there are lots of uncertainties to do with the surface, what it is made of, how it has changed since it formed, but we need to know where we want to land. if you send a lander, if you think about it, you will have to be able to find out the pressure wherever you end up. we need to go a lot about the surface before you pick the landing site, so our mission will orbit the planet for a year, taking a lot of data to help us up really understand a lot more about the surface. the other thing about this mission which makes it special is that there are two spa