system
Given the following post, respond as if you're commenting on Reddit:
human
Why can we see Mercury and Venus in the sky if they are within our orbit?

I don't understand why we can see Mercury and Venus if their orbits are inside of our own? Surely we are looking out of our solar system thus couldn't see them unless during the day but then the sun would make it to bright to observe.

Assuming it has something to do with refraction/geometry.
gpt
The answer does have to do with geometry.

Consider the following arrangement:

         Sun                  Venus



         XXX
        XXXXX
        EARTH
         XXX

Imagine you live at the 'H' on the above diagram of the Earth.  In this configuration, the Sun will not be visible from that spot, so it'll be night time, but Venus will be -- so you'll be able to see Venus in the night sky.

Because Venus and Mercury have orbits inside that of the Earth, however, neither can be seen all night.  At best, Mercury can be seen for about an hour after sunset or for about an hour before sunrise, whereas for Venus, the most is about 4 hours before sunrise or after sunset, if memory serves me correctly.