There are plenty of topics still needing research. I’m in the meteorology field, so I can only tell you about those, but I’m sure the same can be said for other fields. For example: some scientists in my field are studying ice crystals in the upper atmosphere. We have no idea why the different sizes and shapes form. There are many theories out there, but we cannot definitively say why different ice crystals form at varying altitudes/conditions. And the kicker is that some of these crystals will form at multiple levels and conditions. As for me, I study stratospheric ozone (here in Laramie, and soon in Antarctica). As much as we know about the ozone layer and that it needs our help, there are still so many unanswered questions. There is new evidence that suggests that the temperature of the stratosphere actually impacts ozone levels indirectly. This is news to us! I think we do know a lot now, and there is really so much information out there, it is a wonder this “series of tubes” we call the internet doesn’t get clogged more often. But I don’t think we will ever stop finding things to research.