Transcript 01 Mercury - The Messenger

Mercury
“The messenger”
Actually SMALLER than at least 2
moons in SS!
Mercury: Closest planet to the sun and the
8th largest(4,880km) in our SS.
Avg. Dist. From sun: .38 AU
(57,910,000km)
Orbit Period: 88 earth days
(shortest)
Rotation Period: 59 earth days
(VERY slow)
Mass: 3.30 x 1023 kg
Mercury has been known since at
least the 3rd millennium BC and
was noted by the Sumerians.
The Greeks named Mercury the
Morning(Apollo) and
Evening(Hermes) stars (even
though they knew that it was one
body)
Too close to the sun to have HST take
pics…..Visited by 1 spacecraft
in 1974-5.
Mariner 10 mapped 45% of the surface
at that time.
Thin Crust
HUGE iron
core (at least
partly molten)
Some impact craters
appear to have
partially filled with
lava. This means…..
Mercury has a VERY eccentric
orbit:
Perihelion = 46 million km
Aphelion = 70 million km
Mercury is HEAVILY cratered, much like our
moon. If it is about the same age as our
planet, why does it appear to have so many
more impact craters than Earth does?
Very little atmosphere due to:
1. High temperatures
2. Low gravitational pull
3. Severe solar wind
Could possibly have H20 in
the shadows of its craters???
Temp. varies from
about -180 C to
about 427 C.