Kelvin;Unit of temperature, named after the British physicist Lord Kelvin.
Kepler;Kepler, Johannes 1571-1630, German astronomer and mathematician.
Latitude;Distance of a point at the surface from the equator expressed in degrees.
Launch rocket;Rocket with two to four stages to transport goods into orbit.
Libration;Fluctuations in the Moon's motion that can be observed from the Earth.
Light year;Distance that light travels within the period of one year (approx. 9500 billion kilometers).
Liquid fuel;The liquid fuel of a rocket normally consists of liquid hydrogen and oxygen.
Longitude;Angular distance measured in the equatorial plane between a point on the Earth and the prime meridian (Greenwich).
Luminous intensity;Measurement for the total energy emitted by a star.
Lunar eclipse;When the Moon passes through the shadow of the Earth, we can observe a total or partial lunar eclipse.
Lunar orbit;Elliptical orbit of the Moon about the Earth. The orbit is strongly influenced by the gravitational force of the Sun.