Chapter 17 Notes
The Moon
Our calendar is tied to the phases of the moon. 29.5 days to circle the Earth.
July 20, 1969 Apollo 11 landed on the moon. The astronauts placed a reflector to reflect the ray of an Earth-based laser beam.
Determine the rate of continental drift
Detect any change in the location of the North Pole
Determine the orbit of the moon more accurate
Moon is 2nd brightest object (Sun being the first)
Standing on the moon, you would see a sunrise and sunrise every 29.5 days.
No magnetic field. Some of the rocks brought back had a slight magnetic field. Its origin is unknown.
Surface of the moon has craters, basins, plains, rays, mountain ranges, and faults.
Large flat areas are called Maria or plains and are believed to be craters that were filled with lava. Appear very dark. 14 major plains that face the Earth cover 50% of the moon.
The surface of the moon has layers of loose debris called regolith (dust) which has a depth of less than 33 feet on the flat lunar plains.
Rays- streaks that surround an impact crater
Rills- long, narrow trenches or valleys; steep walls, flat bottoms
Moonquakes are thought to cause rills.
The mountain ranges have peaks as high as 6100 meters.
Fault- a break or fracture in the surface of the moon along which movement has occurred
Apollo 11, 12, 15, 16, and 17 landed on moon.
The moon revolves eastward around Earth in an elliptical orbit. Its orbital plane is tilted 5 degrees with respect to Earth’s orbital plane. The 5 degree tilt allows the it to be overhead at any latitude between 28.5 deg. North and 28.5 deg. South latitude.
Two different lunar months:
Sidereal month- 27.33 days. It is the time for the moon to turn 360 degrees and align 2 times with a star other than the Sun.
Synodic month- time to align with the Sun 2 times. It takes 29.5 days. The moon actually revolves more than 360 degrees because the moon and the Sun are both moving.
The moon rises in the east and sets in