As far as I know, we know very little about
what layers other planets have.
It is possible that they have them, but we have
not been able to determine this for sure.
Scientists discovered the layers in the earth by
sending sound waves through the earths crust and
monitoring how long it took for the sound to get
back. Different layers of material will allow the
sound to travel at different rates. So, if we did
this kind of test on other planets, we could
determine if they had layers as well.
Planetary scientists are pretty sure that
Mercury, Venus and Mars also have these layers.
Their cores are mostly made of iron and their
mantles are probably made of similar basaltic
material. Their crusts are made up primarily of
basaltic rock versus the Earths crust which has so
many different rock types (granite, sedimentary
Mercury no longer has a molten mantle and is
completely solid. Venus probably still has a
molten mantle because its entire surface is
relatively recent in geologic terms, about 500
million years old. (Earth is 4.6 Billion years
old). Mars may also still have a molten mantle
but is fairly geologically inactive meaning it has
no plate tectonics, earthquakes or active
Not just planets have a core, mantle and crust.
Several moons in our solar system have them! The
Moon has a core and mantle similar to Earths but
the crust is basaltic rock. Last but not least,
the moons Titan, Triton, Titania and Ganymede have
silicate cores (minerals containing the element
silicon), mantles made of water and ice, and
crusts of ice.
(Thanks to Diane Hanley,
Geologist, Science Center of NH)
Click Here to return to the search form.