LABES   :   

A landslide.

LABYRINTHUS   :   

An intersecting valley complex.

LACUS   :   

A lake

LAGRANGIAN POINT   :   

One of the solutions to the three-body problem discovered by the eighteenth century French mathematician Lagrange; the two stable Lagrangian points, L-4 and L-5, lie in the orbit of the primary body, leading and trailing it by a 60-degree arc.

LATITUDINAL BIODIVERSITY GRADIENT   :   

The increase in species richness or biodiversity that occurs from the poles to the tropics, often referred to as the latitudinal gradient in species diversity.

LAVA   :   

A general term for molten rock that is extruded onto the surface.

LAVA TUBE   :   

A tunnel formed underneath the surface of a solidfying lava flow.

LEADING HEMISPHERE   :   

The hemisphere that faces forward, into the direction of motion of a satellite that keeps the same face toward the planet.

LECITHIN   :   

A major component of cell membranes containing equal amounts of saturated and monounsaturated fatty acids, phosphate, and choline. Lecithin is a member of the lipid group called phospholipids. Its biochemical name is phosphatidylcholine (PC).

LEE   :   

The side of an object that is sheltered from the wind.

LEPTONS   :   

Leptons are indestructible and highly unreactive: they may join in the atomic party but do not dance. You cannot combine leptons to make bigger particles. Examples of leptons include: electrons, positrons, neutrinos and muons.

LEUKOCYTES   :   

The white blood cells of the immune system, that defend the body against infectious diseases and foreign materials are known as leukocytes.

LEVEE   :   

An embankment, continuous dike or ridge.

LIFE EXPECTANCY   :   

Term usually used at birth, indicating the average age that a newborn can be expected to attain.

LIFE HISTORY STRATEGY   :   

An organism's allocation of energy throughout its lifetime among three competing goals: growing, surviving, and reproducing.

LIGHT   :   

The electromagnetic radiation that can be detected by the human eye is known as light.

LIGHTENING   :   

A powerful flash of electricity between the negative electrical charges in clouds or between a cloud and the ground.

LIMB   :   

The outer edge of the apparent disk of a celestial body.

LINEA   :   

An elongate marking.

LINEAMENT   :   

Linear topographic feature that may depict crustal structure.

LITHOSPHERE   :   

Equivalent in part to the crust, the lithosphere comprises of a number of tectonic plates that 'float' on the asthenosphere.

LOBATE   :   

Having lobes or resembling a lobe.

LUMINOSITY   :   

The radiation amount that is emitted by a star or celestial object at a given time is known as Luminosity.