A new virus called SARS-CoV-2 is a coronavirus that has caused an outbreak of a disease called COVID-19.
Public health groups, such as the World Health Organization and the U.S. Centers for Disease Control and Prevention, are still learning about the virus, monitoring the disease it causes, and researching potential ways to stop it. You can read all about the coronavirus and COVID-19 at our sibling site, LiveScience.
But me being me, my mind went straight to Mars. I have long been aware of science fiction’s vision of Earth receiving space souvenirs that carry organisms that might be dangerous to Earth’s fragile biosphere — that’s me, and you, too! Such arrivals could be accidental, or they could be purposeful.
Meanwhile, President Donald Trump’s budget request for NASA supports the development of the Mars sample return mission, a robotic program that would haul back the goods from the Red Planet. What if such samples turned out to be dangerous, and contagiously so? Are there some Mars-oriented lessons to be learned from COVID-19 and other major infectious diseases?
In 1973, Carl Sagan published “The Cosmic Connection — An Extraterrestrial Perspective,” offering this view of Martian pathogens:
“Precisely because Mars is an environment of great potential biological interest, it is possible that on Mars there are pathogens, organisms which, if transported to the terrestrial environment, might do enormous biological damage — a Martian plague, the twist in the plot of H. G. Wells’ War of the Worlds, but in reverse. This is an extremely grave point. On the one hand, we can argue that Martian organisms cannot cause any serious problems to terrestrial organisms, because there has been no biological contact for 4.5 billion years between Martian and terrestrial organisms. On the other hand, we can argue equally well that terrestrial organisms have evolved no defenses against potential Martian pathogens, precisely because there has been no such contact for 4.5 billion years. The chance of such an infection may be very small, but the hazards, if it occurs, are certainly very high.”