Civilized aliens coming from Mars in spaceships to build the pyramids
I'm writing a classic Mars-pyramid story in which some Martian aliens ride in a spaceship and come to Earth and build the Egyptian pyramids. Their environment on Mars is very dry, there are no rivers--there used to be rivers but they dried up and now they're digging very deep wells to get groundwater--but there's lots of stone (that's what the Egyptian pyramids are really made of). They eat Martian plants, which are all blue. The aliens have already put up satellites around the Earth (they're high-tech aliens) and they've seen what the Earth is like. They see that there are lush rainforests, rivers, and green plants. They like it so they come to Earth and they land in Egypt. Actually, they originally didn't want to land in Egypt; they wanted to land in the Nile Delta, but their spaceship's camera failed and they didn't have something like GPS, so they could only randomly land. 920
They landed in the eastern desert of Egypt and they see that it isn't like what they thought Earth was. Now, they're lost. They go back into the spaceship and see if there's anything to help them get to where they wanted to go, and after hours of searching, the captain finds a drone with a camera. They hop back into the spaceship and use the drones to navigate, and they get to where they wanted to go. So, they settle down somewhere here that hasn't previously been settled by humans.
However, one day, they decide to conquer Egypt since their colony on Egypt has run out of resources and they don't want to go back to Mars. However, their colony doesn't have enough military strength to defeat the Egyptians, so they send a group in the colony back to Mars to get military reinforcements; these aliens are okay with just going back to Mars to get military reinforcements, but they wouldn't be fine with returning to Mars and settling in Mars again. They conquer Egypt, and they decide to build a big pyramid as a monument to record their conquest of Egypt.
So, what could the alien's technology look like? Thanks! 920