astronomy 101
Terms : Hide Images
| 1296920919 | solar system | sun, planets, and all the other objects that revolve around the sun | 0 | |
| 1296920920 | milky way | A large spiral galaxy that is home to Earth and the rest of our solar system, and about a trillion stars. | 1 | |
| 1296920921 | galaxy | (astronomy) a collection of star systems | 2 | |
| 1296920922 | universe | All of space and everything in it | 3 | |
| 1296920923 | AU | average distance from the earth to the sun | 4 | |
| 1296920924 | LY | average distance light travels in a year 10 trillion km | 5 | |
| 1296920925 | mega LY | ... | 6 | |
| 1296920926 | Kilo light year | ... | 7 | |
| 1296920927 | Extrasolar planet | a planet orbiting a star other than the sun | 8 | |
| 1296920928 | Constellation | A group of stars that form a pattern in the sky | 9 | |
| 1296920929 | celestial sphere | Imaginary globe where Earth is at the centre and provides an easy way of describing position of objects in sky | 10 | |
| 1296920930 | North celestial pole | Point directly over Earth's North Pole | 11 | |
| 1296920931 | South celestial pole | point directly over Earth's South Pole | 12 | |
| 1296920932 | celestial equator | an imaginary circle created by extending Earth's equator into space | 13 | |
| 1296920933 | ecliptic | path of the sun and the planets | 14 | |
| 1296920934 | zodiac | Constellations along the ecliptic | 15 | |
| 1296920935 | equinox | Either of the two days of the year on which neither hemisphere is tilted toward or away from the sun. | 16 | |
| 1296920936 | solstice | Either of the two times of the year when the sun is at its greatest distance from the celestial equator | 17 | |
| 1296920937 | new moon | Moon phase that occurs when the Moon is between Earth and the Sun, at which point the Moon cannot be seen because its lighted half is facing the Sun and its dark side faces Earth. | 18 | |
| 1296920938 | full moon | Looks like a ball. Has all light reflected | 19 | |
| 1296920939 | waxing | (of the moon) pertaining to the period during which the visible surface of the moon increases | 20 | |
| 1296920940 | waning | (of the moon) pertaining to the period during which the visible surface of the moon decreases | 21 | |
| 1296920941 | gibbous | Moon phase in which more than half of the Moon appears to be illuminated. | 22 | |
| 1296920942 | crescent | Moon phase in which less than half of the Moon appears to be illuminated. | 23 | |
| 1296920943 | lunar eclipse | Earth blocks sunlight from reaching the moon | 24 | |
| 1296920944 | solar eclipse | Occurs when the Moon passes directly between the Sun and Earth and casts a shadow over part of Earth. | 25 | |
| 1296920945 | umbra | the exact shadow on the earth | 26 | |
| 1296920946 | penumbra | shadow surrounding the distinctly sharp area of a shadow called the umbra. | 27 | |
| 1296920947 | greenhouse effect | Anticipated increase in Earth's temperature caused by carbon dioxide (emitted by burning fossil fuels) trapping some of the radiation emitted by the surface. | 28 | |
| 1296920948 | greenhouse gases | Carbon dioxide, methane, water vapor, and others are transparent to sunlight and trap heat radiating to earth back towards space. | 29 | |
| 1296920949 | infrared radiation | Invisible energy felt in heat; has wavelengths longer than red light. | 30 | |
| 1296920950 | carbon cycle | The organic circulation of carbon from the atmosphere into organisms and back again | 31 | |
| 1296920951 | Ozone layer | Layer of the stratosphere with a high concentration of ozone; absorbs most of the Sun's harmful ultraviolet radiation | 32 | |
| 1296920952 | scarps | Huge cliffs thought to have formed as the planet cooled and contracted | 33 | |
| 1296920953 | lava basins | flat plains that have been paved due to lave from volcano eruption | 34 | |
| 1296920954 | lunar maria | seas of cooled flat plains of lava from a puncture-not a volcano | 35 | |
| 1296920955 | impact theory | the Moon formed from gas and debris thrown off Earth whe a Mars sized meteor struck it billions of years ago, the material orbited the Earth and coalesced to form the Moon | 36 | |
| 1296920956 | dwarf planet | orbits the Sun; sphere shape; has not cleared the region of its orbit; not a moon | 37 | |
| 1296920957 | kuiper belt | A region of the solar system that is just beyond the orbit of Neptune and that contains small bodies made mostly of ice | 38 |
