Here's why:

* Lunar Phases: The third quarter moon is the phase where half of the moon's surface is illuminated, and it appears as a half-circle in the sky.

* Moon's Orbit: The moon orbits the Earth, and it takes about 29.5 days to complete one full orbit.

* Position Relative to the Sun: The third quarter moon is positioned opposite the sun in the sky.

* Sunrise and Sunset: Since the third quarter moon is opposite the sun, it rises around sunset and sets around sunrise. It reaches its highest point in the sky around midnight, when the sun is on the other side of the Earth.

So, if you want to catch a glimpse of the third quarter moon at its highest point, look up around midnight.