February is a blockbuster month for Mars missions. The United Arab Emirates and China have both arrived successfully in Martian orbit this week, and NASA is due to land its Perseverance rover on the red planet next Thursday.
All of these missions are, to some degree, tasked with assessing whether Mars might have hosted life in its distant past, billions of years ago. This question is not only crucial to our understanding of Mars’ habitability, it also has implications for life on Earth: many scientists think that life may have started on Mars first, only to spread to Earth, through a process called panspermia.
Amir Siraj, a student studying astrophysics at Harvard University, has co-authored several papers about panspermia, which he called a “very interesting theory.”
“We know that exchange between the Earth and Mars does exist,” Siraj said in a recent VICE News interview. “We see Martian meteorites and there is absolutely reason for us to think that if there was biology on Mars at some point, then it could have been brought to Earth.”
“It’s very difficult to ascertain the origins of life on Earth,” he added, “but the idea that it could have come from Mars is far from a wild one.”
The interplanetary panspermia idea hints that you, me, and potentially every lifeform on planet Earth may be descended from microbial Martians that existed some four billion years ago. But Siraj doesn’t stop at Mars; he has also studied the possibility that life could hitch rides on rocks that traverse interstellar space.
Given that two interstellar objects have been spotted hurtling through our solar system in recent years, it’s clear that objects do hop between star systems, though the odds that any life-forms could survive these enormous voyages are low.
In addition to his work at Harvard, Siraj is an accomplished pianist pursuing a master's degree at the New England Conservatory of Music. Check out the interview to hear his thoughts about the logistics of panspermia, the powerful connection between music and astronomy, and the impact that discovering alien life might have on humanity.