By Kenneth Chang
Enceladus is the coolest place in the solar system you’ve likely never heard of. And Enceladus, one of the moons of Saturn, is indeed cool — its surface temperature averages about minus-325 degrees Fahrenheit. It is also the shiniest object in the solar system, reflecting almost all of the light that hits it.
It became even more amazing when scientists looking at photos taken by NASA’s Cassini spacecraft reported last year that geysers of water were shooting out of Enceladus’ south pole. Enceladus is small, only about 300 miles wide, so it cannot have a hot, molten core like the Earth. Yet some force was melting ice in its interior and propelling it into space, where it refroze into tiny ice crystals. Some of the ice crystals fell back down, and that explains the moon’s extra-reflective coating.
The discovery also vaulted Enceladus onto the short list of places in the solar system that could be home to life. (The necessary ingredients are liquid water, energy and organic molecules. Enceladus has at least two of those.)
NASA announced Wednesday that it is planning to tweak the trajectory of Cassini so that next March it will pass through the cloud of ice crystals and within 19 miles of Enceladus’ surface. Cassini’s instruments might be able to sniff out other molecules from Enceladus and give scientists a better of idea of why there is a geyser at all.
Mars rover update: After some hopeful signs last week, the situation again turned dire for Opportunity, stuck in a still continuing dust storm. Part of the problem is a catch-22. To save power, most of the electronics were turned off. Without the heat produced by the electronics, the rover got colder. The nighttime temperature in the electronics module has fallen to minus-35 degrees Fahrenheit, and that is within 3 degrees of setting off Opportunity’s emergency “survival heaters.” But then, the power to run those survival heaters could raise the power usage above what its solar panels are producing, and its batteries would drain down.
Enceladus (Credit: NASA)
Fausto Intilla's web site: www.oloscience.com