5CounterclockwiseIn a direction opposite to that in which the hands of a clock rotate.
6Rotational AxisThe Earth is rotating around an imaginary axis at a 23.5° tilt. It points in the same direction relative to the stars, so that the North Pole points towards the star Polaris (North Star).
7Vernal EquinoxEarth reaches a point where the tilt is not toward or away from the Sun, and the lengths of day and night are the same all over Earth. March 21st.
8Summer SolsticeEarth’s northern hemisphere is tilted toward the Sun and days become longer and warmer. June 21st.
9Autumnal EquinoxEarth reaches a point where the tilt is not toward or away from the Sun, and the lengths of day and night are the same all over Earth. September 22nd.
10Winter SolsticeEarth reaches a point when the northern hemisphere is tilted away from the sun and the hours of daylight are the shortest. December 21st.
11EclipseThe partial or complete hiding from view of an astronomical object, such as the Sun or Moon, when another astronomical object comes between it and the observer.
12Solar EclipseWhen the Moon blocks the Sun or a part of it.
13Lunar EclipseWhen the Earth casts a shadow on the Moon.
14New MoonWhen the Moon is between the Earth and the Sun; the illuminated portion is on the backside we can’t see.
15Waxing CrescentDuring this phase, part of the Moon is beginning to show. We say that the Moon is "waxing" because each night a little bit more is visible for a little bit longer.
16First Quarter MoonComes a week after new moon; rises at noon and is high overhead at sunset, then sets around midnight.
17Waxing GibbousWhen most of the Moon is visible we say it is a Gibbous Moon. During this phase, the Moon remains in the sky most of the night.
18Full MoonWhen we can observe the entire face of the Moon, we call it a Full Moon. The Moon is opposite the Earth and the Sun.
19Waning GibbousInstead of seeing more of the Moon each night, we begin to see less and less of the Moon each night. This is what the word "waning" means.
20Third Quarter MoonComes about three weeks after new moon; rises around midnight, appears at its highest in the sky around dawn, and sets at noon.
21Each night less of the Moon is visible for less time. Waning CrescentEach night less of the Moon is visible for less time.
22Gravitational Attraction Force of attraction between all masses in the universe, especially the attraction of the Earth’s mass for bodies near its surface.
23Neap TidesTides that are the least extreme; happen twice a month, at first and last quarter moon phases.
24Spring TidesTides that are most extreme; occur twice a month, at full and new moon phases.
25High Tide The tide when the water is at its greatest height.
26Low Tide The tide at its lowest level at a particular time and place.