Paragraph 1
We know
about the centre of Earth. Geologists believed it had just one
– a hot mass of
rock surrounded by a rock mantle. This is a ring between the earth's
and core. The core is 2,900 km below Earth's
. It has a
of 3,485 km. Scientists believe there may be a
core. A geophysicist analyzed
from a 560-km-deep
. It showed the possibility of a second core at the
of the mantle.
