Europa Could Briefly Sustain Life When the Sun Becomes a Red Giant Star, Scientists Say

Life in the solar system may not entirely end when the sun begins its dramatic transformation into a red giant star. Instead, a brief window of potential habitability may open on Europa, Jupiter's icy moon, according to new research. Scientists now suggest that as the sun expands and its habitable zone shifts outward, Europa could temporarily offer conditions suitable for life, though the opportunity would last only a few hundred million years, fleeting on cosmic timescales, but not insignificant.

Europa May Host Microbial Life for 200 Million Years After Sun Becomes a Red Giant

As per a new study from the Carl Sagan Institute at Cornell University, soon to be published in the Monthly Notices of the Royal Astronomical Society, the red giant sun's energy output could reach as far as Jupiter's orbit. While Jupiter itself will remain inhospitable, its moon Europa may receive enough combined heat from both solar radiation and Jupiter's increased reflection to melt parts of its icy crust. This warming could expose or even evaporate subsurface oceans long believed to exist beneath its frozen shell.

Researchers estimate that Europa's surface will sublimate significantly on the side facing Jupiter, while equatorial regions will suffer water loss due to convective heat transport. Yet, the northern and southern regions on the side opposite Jupiter might retain more water, creating a modest water-vapour atmosphere. Scientists note that this could preserve the conditions needed to sustain life for as long as 200 million years.

The briefer span of Earth history might have been long enough for microscopic life to flourish or endure, in particular if life thrives somewhere below Europa's ice. This finding could open new paths for astrobiological investigation, including future telescopes with the capability of fishing for biosignatures on ice-covered moons that orbit red giant stars.

Findings such as the exomoon discovery could open a new chapter in that search, with the possibility that after humans die out or destroy themselves, Europa might be all that remains of life in the solar system.