1. NOTES: MERCURY Mariner 10 in 1973 mapped 60% of Surface. D = 1.4 D(moon) =.35 D(earth) No axial tilt Day = 176 earth days = twice orbital period 1.Rocky mantle Same density as earth implying large metallic core, solid because it is a small planet. Cut down by a large impact or early solar bombardment. 2. Extremely thin atmosphere of helium, sodium, and potassium continually escaping into space. Temps: 425K to 100K (-170C). 3.Rotates 3 times for every 2 revolutions--same side faces sun at alternate perehelia (semiperiodic tidal locking). 4.Features: craters and basins filled with lava (like moon) and scarps formed as planet cooled. Core was once liquid. 5. A stronger magnetic field than expected, considering slow rotation and cool core. A distorted magnetosphere. 6. Same sequence and timing of formation of moon and mercury. No plate techtonics. 7. Large impact crater--Caloris Basin (like Orientale Basin on moon) --jumbled hills on opposite side of planet.

2. Mercury looks like the Moon

3. Mariner 10 in 1973 mapped 60% of Surface. Messenger flybys (  2010, filled out that map to 97%). Messenger set to orbit in 2011. D = 1.4 D(moon) =.35 D(earth), No axial tilt Day = 176 earth days = twice orbital period

4. Rocky mantle. Mass determination and size implies large metallic core, solid because it is a small planet. Mantle cut down by a large impact or early solar bombardment.

5. Extremely thin atmosphere of helium, sodium, and potassium continually escaping into space. Temps: 425K to 100K (-170C).

6. Rotates 3 times for every 2 revolutions--same side faces sun at alternate perehelia (semiperiodic tidal locking).

7. Features: craters and basins filled with lava (like moon) and scarps (cliffs) formed as planet cooled.

8. Unexpected magnetic field, considering slow rotation and solid, cool core. A distorted magnetosphere. Core may be a permanent magnet.

9. Large impact crater--Caloris Basin (like Orientale Basin on moon) --jumbled hills on opposite side of planetary body.

10. Mercury: up close and personal Same sequence and timing of formation of moon and mercury. No plate techtonics