According to kepler, which planet travels the fastest? earth jupiter mercury neptune

The answer is "Mercury".

Mercury

Explanation:

According to second Kepler's law of planetary motion:  

The line joining the planet and the sun sweeps equal areas in equal amount of time. This describes the speed of the planet.

In order to conserve momentum, the planet closest to Sun would travel fastest and planet farthest from Sun would travel slowest.

Since Mercury is the closest planet to sun, it would be fastest.

second mirror gathers light from a faraway object and reflects it to another mirror. - a.

luster is not a good characteristic to use by itself because luster is the property of minerals that indicates how much the surface of a mineral reflects light. the luster of a mineral is affected by the brilliance of the light used to observe the mineral surface.