Would you not use surprised if you received results that differed from what you were expecting? I'm surprised something 2.5 time heavier than iron would be in the upper atmosphere at all. Wouldn't that be something that fell back to the surface? Then again, I'm not a planetary scientist type, so I'd probably be surprised much more frequently.

It's not like they are shocked or disappointed. To me, it just reads they received info they will now be looking at further than they were expecting to need. Maybe intrigued would be appropriate instead if you consider "surprised" to be as lazy as "very".