The frozen surface of Jupiter’s icy moon Europa is seen in extreme detail in these remastered picture made from images taken by NASA’s spacecraft Galileo in the late 1990s. A new study suggests that the ice on Europa can move between the poles of the moon and the equator.
Ice on Jupiter’s moon Europa may drift across the satellite’s surface from the equator to the poles, or vice versa, at a literally glacial pace, a new study found.
Potential future missions to Europa could analyze this ice flow to discover tips about the question or the ocean hidden under the ice of the surface may be warm enough to support life, researchers said.
Europe is almost the size of the moon. Under an icy shell to more than 18 miles (30 km) thick, Europa may have an ocean perhaps 100 miles (160 km) deep, scientists have said. [Europa in Photos: Jupiter Icy Moons]
Since there is life virtually wherever water on Earth, in Europe, one of the most obvious places in the solar system to find extraterrestrial life, said the new study’s lead author, Yosef Ashkenazy, a climate dynamicist at the Ben-Gurion University of the Negev in Israel, and his colleagues. The study, detailed Dec. 4 in the journal Nature Astronomy.
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The study, detailed Dec. 4 in the journal Nature Astronomy
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Europa’s icy crust protects the moon ocean. However, clues about how this underground ocean behaves might be deduced from Europa’s surface, especially regions known as chaos terrains, where the ice is bent and broken into jumbled blocks. This strange areas and up to 40 per cent of Europe’s surface, mostly clustered around the Jovian equator.
Prior work suggests that this chaotic terrain as a result of movement in the ice, making the blocks of the to rise vertically. Now, Ashkenazy and his colleagues have analysed how this ice can also move horizontally about Europe’s surface.
Earlier research suggested that ice may vary in thickness over Europe ‘ s surface, because the poles of the moon are much colder than the equator. The differences in thickness may help the ice cream to float on Europe’s surface, but until now, scientists had not investigated how this flow might behave.
The scientists developed a model of Europa’s shell is composed of warm, soft ice, flowing under a cold, brittle, hard ice crust, a bit like how earth’s crust has running hot and cold rock under colder, more brittle rock. Under Europa’s crust, the model simulated an ocean heated by a hot core and by friction generated by Jupiter’s gravitational pull. [In Europa: Jupiter’s Icy Moon Explained (Infographic)]
Ice cream in motion
The model that Europe’s icy crust was thick enough, the temperature would vary enough in the underground ocean for a sort of churning water, known as convection to occur. “In the atmosphere of the Earth and the oceans, convection is a fast process, but with the ice of Europa, it would take place on the time scale of millions of years,” Ashkenazy said.
If convection occurred within Europe, the ocean, heat can flow from the equator to the poles, enough for the equator to be significantly cool in comparison with the poles, he said. “In this scenario, the ice would flow from the equator to the poles,” Ashkenazy said, because the ice at the equator would km thicker than at the poles.
However, if Europe and the crust is relatively thin and convection does not occur in the ocean, the poles would be much colder than the equator. “This would lead to warmer ice at the equator and thicker ice at the poles, and the pressure gradient would cause ice to flow from the poles to the equator,” Ashkenazy said.
The rate of ice flow would be very slow, on the order of about 0.4 inch (1 cm per year, Ashkenazy said. Still, future missions to Europa would look for signs of this ice flow by measuring how thick the Europe of the crust was at various points in the surface of the moon. Doing so “can help improve our understanding of what is happening under Europe’s surface,” Ashkenazy said.
Original article on Space.com.