Is there life on one of Saturn’s moons?

It’s a small world, just 310 miles in diameter, and until recently was considered one of the least interesting moons in our solar system. But Enceladus, one of 146 moons orbiting Saturn, has become an astronomical hotspot, with scientists discovering it offers one of the best prospects for finding life.

The European Space Agency (ESA) announced that it has begun planning a mission to take a robotic rover a billion miles into space for investigation.

It will be a very difficult task. In addition to the enormous distance that the vehicle will have to travel, it will need huge reserves of fuel to orbit around Enceladus and then land on its ice-covered surface.

Still, the prospect of studying the tiny moon is enticing to astronomers who have discovered that Enceladus, first observed by William Herschel in 1789, has geysers that regularly bubble from its surface and spray water into space. Even more surprising is that it contains complex organic compounds, including propane and ethane.

“Enceladus contains three main components that are believed to be necessary for the emergence of life,” said astronomer Professor Michelle Dougherty from Imperial College London. “It contains liquid water, organic matter and a source of heat. This combination makes it my favorite moon in the entire solar system.”

This view is agreed by the European Space Agency, which recently identified a mission to travel to the moon of Jupiter or Saturn as its next target for a major scientific effort. Such a project is expected to deliver a “transformative scientific return,” according to a team of expert scientists who studied three main targets: Europa, Jupiter’s ice-covered moon Titan, Saturn’s hydrocarbon-rich moon Enceladus. All feature subterranean oceans that hold promise for sustaining extraterrestrial life and will be prime targets of scientific scrutiny.

After months of study, the committee reported a few weeks ago that Enceladus was last on the list among the planets, but should be given priority over other targets. A mission is scheduled to be launched by 2040 with the aim of either landing on the moon or flying through geysers that spray water and carbon-based chemicals from its surface into space. The committee added that it is better to try to achieve both goals, although achieving them is not easy.