Watery curtains flowing from a Saturn moon, NASA cleaning a telescope with snow, and an astronaut sipping the first espresso in space feature among our picks for the best space-related images of the week.
Through the Curtains
Saturn's moon Enceladus is famous for spitting into space—in the early 2000s, NASA's Cassini spacecraft showed that the icy body has plumes of water gushing from cracks in its south polar region. Based on images of the jets, scientists think a pocket of water lies beneath the moon's icy crust that is perhaps as big as Lake Superior. Cassini has even been able to zip through and taste the plumes, finding that they contain salt, organic compounds and other ingredients that help sustain life here on Earth.
But now, Cassini scientists think the plumes of Enceladus may be an illusion. Water is still pouring out of the moon, but the eruptions are more like waving curtains than discrete jets, according to new simulations presented this week in Nature. The cracks that vent the plumes are not perfectly straight, and because of our viewing angle, "folds" in the curtains of erupting water seem brighter, creating phantom jets. Figuring out exactly how water spews from Enceladus should reveal more about its subsurface lake and whether it has the potential to host alien life.