Key Vocabulary Eclipse Vocabulary Annular eclipse Annulus Penumbra Moon Vocabulary Lunar maria Spring tide Neap tide Rays Sidereal period Synodic period Waning Waxing Apogee Perigee Moon info in the textbook: P39-41 p248-249 p285-287 Eclipse Vocabulary Annular eclipse Annulus Penumbra Umbra Lunar eclipse Solar eclipse Eclipse info in the textbook: P42-45
Astronomy 2014 Earth’s Moon
Lunar Maria Huge impact basins that were flooded by lava that now appear as smooth, dark areas Also called “seas” Cover 17% of the Moon Range from about 200 km- 1200 km in size Physical Features: pits & craters Rock type: Basalt
Sea of Tranquility (Mare Tranquillitas) Site of Apollo 11 Landing Selected because of level terrain
The map shows a lack of major maria on the lunar farside The map shows a lack of major maria on the lunar farside. Two causes: 1) lunar surface is on farside has higher elavations 2) the crust seems to be thicker on the lunar farside than on the nearside. Differences should make it harder for mare magmas to reach the surface on the lunar farside.
Blue: about 10km in crustal thickness (likely reduced from 25-30 km in crustal thickness due to impacts) Red: 50+ km in crustal thickness
Spring Tide and Neap Tide Highest and lowest monthly tides Occur at the new and full moon Caused by the alignment of the Sun and Moon with the Earth Neap Tide Lower than average tides Occur at the first and third quarter moon Created when the pull of the Sun is perpendicular to the pull of the Moon on the Earth
Lunar Craters Bowl-shaped depression left by the impact of an object that struck the lunar surface Shape is due to material flying out in all directions as a result of the explosion upon impact Craters are the most common surface features on the Moon Major Parts Floor Central Peaks Walls Rim Ejecta Rays
Crater Rays Bright streaks extending away from the crater sometimes for great distances, composed of ejecta material.
Tycho Large, complex impact crater with terraced walls, flat floor, and central peaks Most visible crater on the near side of the Moon 85 kilometers wide, 4.8 km deep Formed about 200 million years ago from an oblique impact Surrounded by a dark ring and long rays Rays are not distributed equally in all directions Rays located primarily to the lunar east, south, and northwest No rays to the west
Sidereal Period and Synodic Period Sidereal Period: the Moon’s actual orbital period around the Earth Synodic Period: time between successive recurrences of the same phase (for example: full moon to full moon)
Waxing and Waning Waxing Face of the moon is increasing into view New Moon Full Moon Waning Face of the moon is decreasing out of view Full Moon New Moon
Apogee and Perigee Apogee Point at which Moon orbits furthest from Earth Moon appears smallest Perigee Point at which Moon orbits closest to Earth Moon appears largest
Astronomy 2014 Eclipses
Penumbra Umbra Outer regions of an object’s shadow Lighter than middle portion Umbra Center region of an object’s shadow Darker than outer portion
Lunar eclipse Occurs when the Moon passes through Earth’s shadow Can only occur at full moon Three Types: Total Partial Penumbral http://www.youtube.com/watch?v=fXPJIDrzo0w
On the back of your packet, sketch this graphic showing the arrangement of the Sun, Moon, and Earth for a lunar eclipse.
Solar eclipse Occurs when the Moon’s shadow falls on Earth Can only occur at new moon Three Types: Total Partial Annular http://www.youtube.com/watch?v=_201ttTSG30
Annular Solar Eclipse Type of Solar Eclipse Occurs when the Moon is directly in front of the Sun, but does not completely block it out Annulus: Ring of sunlight that is seen around the dark Moon shadow