SORU: aşağıdaki parçaya göre cevaplayınız
The passage is mainly concerned with ----.
Earth and Venus, being roughly the same size and
distance from the sun, are often regarded as twin
planets. So it is natural to wonder how the crust of
Venus compares with that of our own world. Although
centuries of telescopic observations from Earth could
give no insight, beginning in 1990 the Magellan
space probe's orbiting radar penetrated the thick
clouds that enshroud Venus and revealed its surface
with stunning clarity. From the detailed images of
landforms, planetary scientists can surmise the type
of rock that covers Venus. It seems that our sister
planet is completely covered by rocks of basaltic
composition, which are very much like the dark, finegrained
rocks that line the ocean basins of Earth.
Magellan's mapping, however, failed to find extensive
areas comparable to Earth's continental crust.