Transcript Mercury

Planets (inner)
Power Point guide to ….
By Mr. Hoover
Similar Bodies
Mercury Facts
• Diameter…4800 Km
• radius……2/5
• Distance to sun….. .4A.U.
• Gravity…… 2.8
• Axis tilt….. 0o
• Density…… 5.42 g/cm3
Mercury Facts
• Rotation…. 59 days
• Revolution….. 88.0
• Slow Rotation: Mercury makes
only 3 rotations every 2 orbits.
• This is an example of spin-orbit
Mercury Facts
• Tilt of Axis…… 0.0o
• Orbital Inclination…. 7.0
• Surface Pressure…… 0
• Max. Surface Temp….. 452 K
• Surface Temp.: high of 800°F
during the daytime, -280°F at night
Mercury Rising
Mercury’s Atmosphere
almost none
weak gravity and very hot => gasses
sodium, potassium from rocks outgassing
hydrogen and helium from Sun
no weather =====> very little
erosion ====> old surface
Mercury Facts
• Atmospheric composition
• He….. 42%
• Sodium…. 42 %
• Oxygen…… 15%
• Other…. 1%
Mercury’s Interior
Why a thin Mantle?
To hot for lighter elements to collect
Collision with large planetisimal
knocked mantle away
Very powerful solar wind blew
mantle away
Mercury in transit
Mercury in transit
• Mercury has phases like our Moon.
• Mercury is always seen near the
Sun as a "morning star" or
"evening star".
• Surface Features
–Impact Craters
–Scarps (or cliffs)
–Almost No Atmosphere
–Crater Rays
Caloris Basin
Largest Crater
on Mercury
• Mercury was first imaged by
the Mariner 10 spacecraft.
Mariner 10
End of Chapter.