Other planets may never be as hospitable as Earth – study

Scientists deal a blow to the quest for organisms inhabiting worlds besides Earth, saying our planet is unusual in its ability to host liquid water — the key ingredient for life.

It was thought likely that distant worlds orbiting stars similar to our Sun would go through water-rich phases.

This would happen when the young, dim star of an icy, lifeless planet — such as early Earth — starts warming, becomes Sun-like, and melts the ice on planets orbiting it at just the right distance — the so-called “Goldilocks” zone.

Icy orbs in our own Solar System, including Jupiter’s moon Europa and Saturn’s Enceladus, or “exoplanets” in other star systems, may become habitable in this way, the theory goes.

But a team writes in the journal Nature Geoscience on Monday that this is unlikelier than had been imagined.

Jun Yang, of Peking University in China, and a team used climate models to simulate the evolution of icy planets.

Without atmospheric greenhouse gases — a feature of Earth — the energy required to thaw an icy planet would be so high that it would transit from frozen to inferno without an intermediate, liveable phase, they find.

— AFP