If you suffer from hay fever, you can now get acquainted with your invisible enemy. These are the Scanning Electron Microscope pictures of pollen grains captured by Martin Oeggerli. Take a close look at pollens from different species of plants.
This is what snow crystals look like under a scanning electron microscope. As they fall from the sky, these crystals will accumulate and form even prettier snowflakes. Image: Agricultural Research Service, US Department of Agriculture