Scientists Suggest Earth May Have Sent Life-Bearing Dust to Jupiter’s Moon Europa

Earth may have been sending life toward Europa for millions of years, carried not by spacecraft but by dust hurled into space by micrometeorite impacts.

Scientists from the University of Tbilisi in Georgia developed the hypothesis after evidence confirmed that Europa, a moon of Jupiter, has a liquid ocean beneath its ice. The study, published in a scientific journal from the University of Cambridge, argues that Earth has continuously released particles potentially carrying microbes since life began at least 3.55 billion years ago.

Zaza Osmanov, the study’s author, said micrometeorite collisions in Earth’s atmosphere could propel dust containing bacteria into space at extreme speeds. Using mathematical models, the researchers estimated that trillions of such terrestrial grains may have struck Europa during the existence of its internal ocean.

The estimate takes into account Earth’s ejected material, orbital paths, the chance of a spatial intersection and Jupiter’s gravitational sphere of influence. The resulting flow of dust grains carrying surviving bacteria could reach about 3.2 × 10^8 particles per second. Based on estimates that Europa’s icy surface and ocean are 30 million to 80 million years old, the moon could have received roughly 300,000,000,000,000,000,000,000 particles.

Radiation would deactivate bacteria exposed on the icy surface within about 10,000 years. But the study points to Europa’s Chaos terrains, which cover 20% to 40% of the surface, as a possible route into the ocean. Periodic ice fractures occurring every 1,000 to 100,000 years could allow dust grains to reach liquid water before radiation disables the bacteria. The idea forms part of the panspermia theory, first proposed in 1908 by Svante Arrhenius, which links life on different worlds through transported biological material.