What the coronavirus looks like up close

The images of SARS-CoV-2, the novel coronavirus that first appeared in humans in late 2019, were made using electron microscopy. The virus measures around 100 nanometers, and the smallest wavelengths of light that humans can see measure around 400 nanometers, meaning the virus is too small to see with a standard light microscope. To see something that small, you need a device that uses smaller wavelengths than light. Electrons, when accelerated in a field, behave as a wave with a tiny wavelength to accomplish this.