| Lacerta | The constellation "The Lizard" | |
| Larissa | A moon of Neptune was discovered by Harold J. Reitsema, William B. Hubbard, Larry A. Lebofsky and David J. Tholen on May 24, 1981. Larissa is also designated as "Neptune VII" and "S/1981 N1". In Greek mythology, Larissa was a nymph who was a lover of Poseidon (Neptune). | |
Last Quarter Moon  Last Quarter Moon |
The week between the Full Moon and the Last Quarter Moon the sunlit side of the Moon is called waning (shrinking) gibbous and is shrinking until the lunar disk is half in sunlight and half in shadow. This half lit point is the Last Quarter Moon. After the Last Quarter the sunlit side of the Moon continues to shrink as a waning crescent as the Moon approaches the Sun's position in the sky. | |
| Leda | A moon of Jupiter was discovered by Charles T. Kowal at the Mount Palomar Observatory on September 14, 1974. Leda is also designated as "Jupiter XIII". In Greek mythology, Leda was queen of Sparta who was the mother of Castor, Polydeuces, Clytemnestra and Helen of Troy. | |
| Lens | A piece of transparent material which is used in an optical instrument for forming an image by focusing rays of light. | |
| Lenten Moon | The name of the Full Moon usually in March. Specifically the Full Moon before Ecclesiastical Vernal Equinox (March 21). Sometimes known as the "Worm Moon," "Sap Moon" or the "Crow Moon." | |
| Leo | Leo (The Lion) is a zodiacal constellation, that is, it lies across the ecliptic, an imaginary line across the sky that the Sun, Moon and all the planets except Pluto seem to move along. Leo contains the 'Sickle' asterism which forms the lions head and four spiral galaxies from the Messier catalog M65, M66, M95 and M96. | |
| Leo Minor | The constellation "The Lesser Lion" | |
| Lepus | The constellation "The Hare" | |
| Libra | Libra (The Balance) is a zodiacal constellation, that is, it lies across the ecliptic, an imaginary line across the sky that the Sun, Moon and all the planets except Pluto seem to move along. The constellation was once part of the constellation Scorpius (The Scorpion) until it was renamed by the Romans. The names of some of the stars in Libra still carry this ancient legacy of Scorpius (Zubenelgenubi ('southern claw'), Zubeneschamali ('northern claw'), and Zubenelakrab ('scorpion's claw')). After its association with Scoprpio the stars of Libra were associated with the constellation of Virgo as the 'Scales of Justice' of the goddess Astraea (Virgo), the goddess of justice. | |
| Light Grasp | A measurement of the brightness a telescope can make a view. Light Grasp is the ratio between the area of a telescope's aperture and the area of an average human dark-adapted (scotopic) pupil. | |
| Light Pollution Filter | A telescope filter that blocks the light of mercury and sodium vapor street lights, thus allowing faint nighttime celestial objects to be seen and photographed from cities. | |
| Light-year | A measurement of distance base on how long it takes light to travel in a year in a vacuum (about 5,878,482,164,161 miles). | |
| Long Night Moon | The name of the Full Moon usually in December Specifically the first Full Moon before Yule (December 22 by "The Maine Rule"). Sometimes called the "Cold Moon" or the "Moon before Yule." | |
| Luminosity | The rate at which light is emitted from an object. | |
| Luna | Earth's moon is Luna. Usually referred to as "The Moon." | |
| Lunar | Having to do with the Moon. | |
| Lunar Calendar | Any calendar system based on the phases of the Moon. Islamic, Hebrew and Chinese calendars are examples of lunar calendars. | |
| Lupus | The constellation "The Wolf" | |
| ly | Abbreviation for an "Light-year" which is a measurement of distance base on how long it takes light to travel in a year in a vacuum (about 5,878,482,164,161 miles). | |
| Lynx | The constellation "The Lynx" | |
| Lyra | The constellation "The Lyre" | |
| Lysithea | A moon of Jupiter was discovered by Seth Nicholson at Mount Wilson Observatory in 1938. Lysithea is also designated as "Jupiter X". In Greek mythology, Lysithea was a daughter of Oceanus and one of Zeus' lovers. | |
| The "Stars and Scopes" Glossary was compiled by Peter Ue from various sources on the internet. I tried to correct and edit as much as possible, but I can make no claim or warrenty to the information here. If you find any errors just contact me and I'll try to fix it - Thanks , Peter. |
