Does Mars have a core like the Earth? What are the similarities structurally between the Earth and Mars?
Due to a lack of seismic data for Mars, little is known about the
structure of its interior.
Estimates of the size of Mars' core range
from 2200-4000 km in diameter and account for 6-21% of its mass. It
is believed that Mars' core consists primarily of iron. However, its
weak magnetic field suggests that the core is either small and solid, or
larger and semi-solid or liquid.
Earth's core, on the
other hand, is approximately 7000 km across and
accounts for 32% of Earth's mass. The core consists of both iron and
nickel and is structurally comprised of 2 parts: a
solid inner core and a liquid outer core. Though the temperature of the
inner core is sufficiently hot to melt iron (7400oF, or
4100oC), it remains solid because of the immense pressure
exerted at the interior due to the Earth's weight.
Mars resembles Earth more than any of the other planets despite what
appear to be significant differences. Mars is roughly half the diameter of
Earth, but only about 1/10th its mass. Mars also has seasons like Earth
though it's considerably colder overall (-63oF vs.
59oF on Earth). Unlike Earth, Mars does not have oceans and
lakes, in fact there is very little water at all. And although Mars is
one of the smallest terrestrial planets, it has some of the largest
volcanic and tectonic features in the entire solar system. The
largest of them all is a volcano named Olympus Mons which
stands more than 16 miles (26km) high and 375 miles (600 km) across!
Submitted by Brian (age 12, Arizona, USA)
(September 8, 1997)