Hanta Virus vs Corona Virus What is Coronavirus? Coronaviruses are a species of virus belonging to the family of Coronaviridae. Coronaviruses are envelop viruses with positive-sense single stranded RNA genome. The genomic size of coronaviruses ranges from 26 to 32 kilobases, Hence Coronaviruses are the largest of RNA viruses. Scientists used electron microscope to measure the size of the coronavirus and found that these viruses are spherical in shape having diameter nearly 125 nm, Hence Coronavirus particles are bigger than some dust particles and gases.