| A | B |
|---|
| Leap year | Occurs every 4 years to account for the extra day that adds up because Earth actually takes 365.25 days to revolve around the sun. An extra day is added to February |
| rocket propulsion | A rocket moves forward when gases are expelled from the back of the rocket pushing it in the opposite direction. |
| Telescope | A device that makes distant objects appear closer invented by Gaileo in 1609 |
| Features on the Moon | Maria, craters and highlands |
| Sputnik 1 | The first artificial satellite to circle the Earth was launched by the Soviet Union on Oct. 4, 1957 |
| Tides | The rise and fall of Earth's water every 12.5 hours or so. Due to pull of moon and sun's gravity. Four tides each day in most places. |
| Geosynchronous Orbit | Items revolve around earth at the same rate that Earth rotates. (They appear to stay in one place above Earth) |
| July 20, 1969 | The Rist landing on the moon took place on this date. Flown by Collins the Appollo 11 mission let Neil Armstrong and Buzz Aldren be the first to walk on the moon |
| Yuri Gagarin | A Soviet Cosmonaut(Russian astronaut) who became the first person in space on April 12, 1961 |
| Lunar Eclipse | Occurs at the full moon when Earth is directly between the moon and the sun. Earth blocks sunlight from reaching the moon. More common then solar eclipse. |
| Gravity | Attractive force between 2 objects which depends on the masses of the object and the distance between them |
| Satellite | Any natural or artificial object that revolves around and object in space. The moon is our natural satellite |
| Moon Rocks | Much of what scientists have learned abou the moon came from detailed study of rocks brought back by astronauts |
| Neil Armstrong | The first man on the moon. "That's one small step for man, one giant leap for mankind. |
| Astronomy | The study of the moon, stars and other objects in space. |
| Latitude | The measure of distance from the equator. |
| solstice | Two days a year when the noon sun is overhead at either 23.5 degrees north or south. Mark beginning of summer and winter |
| axis | The imaginary line that passes through Earth's center at the North and South Poles. |
| orbit | The path that Earth takes as it revolves around the sun. |
| rotation | Earth's spinning on its axis... causes day and night |
| revolution | The movement of one object around another...this gives us our year |
| vernal equinox | The spring equinox on or around March marks the beginning of spring in the northern hemisphere |
| eclipse | When the moon's shadow hits Earth or Earth's shadow hits the moon, an eclipse occurs |
| Equinox | Two day during the year when the noon sun is over the equator..means equal night and the length of nigh and day on these days is the same. |
| phase | The different shapes of the moon you see from Earth. The moon goes through the full set of phases about once a mouth. |
| Penumbra | Occurs when the moon passes between the Earth and the sun blocking sunlight from reaching Earth. Only visible from within the umbra!! |
| Umbra | The darkest part of the moon's shadow...come shaped. |
| Solar Eclipse | In this larger part of the shadow part of the sun is visible from Earth. A partial eclipse is seen from within this . |
| Autumnal Equinox | Occurs on or around September 23 and marks beginning of fall in northern hemisphere |
| What does the phase of the moon we see depend upon | How much of the the sunlit side of the moon faces the Earth. |
