Transcript Mercury

Mercury
Part 2, The Planet
Mercury has no Atmosphere
Why?
1. Gravity is too weak,
so escape velocity is low
2. At the equator heat from the Sun
causes gas molecules to move faster
than escape velocity …so they leave!
Surface Temperature
Mercury has the greatest change of temperature of
any planet
High: 700°K (800°F) Low: 100°K (-280°F)
Because It has the …
1. Heat: It is closest to the Sun
2. Time: It has a very long solar day (176 Earth Days)
3. No Atmosphere to hold onto the heat
Surface Features
Craters: Cover
Mercury..like
the Moon
But many are
filled with lava
plains, like lunar
maria.
The Caloris Basin
The largest crater
is the Caloris
Basin
1300 km
across!
Scarps
Long
Cliffs
criscross the
surface
created
by shifts
in the
crust as
it cooled
The “Weird Terrain”
This “hummocky”
terrain on the
opposite side of
Mercury from the
Caloris Basin
Was probably caused
when shockwaves
from the impact at
the basin met
Mercury’s Interior
Mercury probably
has a core which
is larger
compared to the
planet than
Earth’s.
The Crust and
Mantle are
relatively thin.
As no probes have
landed there we
can’t be sure