Question

(PUCRS – adapted) Read the text.

The agency has no official plans for a mission to the Jovian moon, whose icy crust covers a watery ocean in which life could theoretically exist. But spurred by intense congressional interest and several recent discoveries, NASA is seeking ideas for instruments that could fly on a mission to Europa.

The groundswell of enthusiasm is likely to be bolstered by the latest big news, reported on 7 September, that there may be giant plates of ice shuffling around on Europa – much as plates of rock do on Earth (S. A. Kattenhorn and L. M. Prockter Nature Geosci. 2014). Such active geology suggests that Europa’s icy surface is connected to its buried ocean – creating a possible pathway for salts, minerals and maybe even microbes to get from the ocean to the surface and back again.

Kattenhorn and Prockter propose a system of plate tectonics that involves a shell of ice a few kilometers thick sliding around on warmer, more fluid ice. When one plate hits another and begins to dive downwards – or subduct – it melts and becomes incorporated in the underlying ice, the duo proposes.

Places have already been spotted on Europa where fresh ice crust is being born, but the latest research is the first to pinpoint where it might be going to die.

But without high-resolution images from more areas, researchers cannot tell whether subduction might also be happening in other locations. If it turns out to be common, it might mean that the moon could be cycling life-friendly compounds between the surface and the deep, and that substantially increases the chance that its ocean is habitable, says Michael Bland, a planetary scientist at the US Geological Survey in Flagstaff, Arizona.

The discovery adds to excitement set off in December, when scientists reported plumes of water vapour spurting out at Europa’s south pole. The plumes have not been seen since, and they may or may not be related to Europa’s newly appreciated system of plate tectonics. NASA now needs to figure out what kind of mission might

best explore these discoveries.

Adapted from: Acesso em: set. de 2014.



According to the text,

Escolha uma:
a. NASA is sending a mission to Europa soon.
b. the compounds of the ocean cause the ice movement.
c. subduction is happening all over Europa’s surface.
d. the system of plate tectonics could be related to the plumes of water vapour.
e. Europa is friendly to human life.

Answer 1

d) The system of plate tectonics could be related to the plumes of water vapour.