Transcript Mercury
Planets (inner) Power Point guide to …. By Mr. Hoover Mercury Mercury Similar Bodies Moon Mercury 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 Mercury • Slow Rotation: Mercury makes only 3 rotations every 2 orbits. • This is an example of spin-orbit resonance. Mercury Facts • Tilt of Axis…… 0.0o o • 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 escape 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 • 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 • Mercury was first imaged by the Mariner 10 spacecraft. Mariner 10 End of Chapter.