true, as the earth rotates the sun hits the surface of the planet; causing the day and night cycle.
if an astronaut takes an object to the moon, the object's weight will change but its mass will be the same. (c)
-- from january 15 to february 6 is a period of 22 days.
-- the period of the full cycle of moon phases is 29.53 days.
-- so those dates represent (22/29.53) = 74.5% of a full cycle of phases.
-- that's almost exactly 3/4 of a full cycle, so on february 6, the moon would be almost exactly at third quarter. that's the left half of a disk (viewed from the northern hemisphere).
matter that emits no light at any wavelength is called dark matter.