Lunar means relating to the moon. When scientists talk about lunar craters, they mean the bowl-shaped dents covering the moon's surface. A lunar eclipse happens when Earth's shadow falls across the moon, temporarily darkening it.

You'll see lunar used in many contexts: lunar missions are space flights to the moon, like the Apollo 11 mission that first landed humans there in 1969. A lunar calendar tracks time by the phases of the moon rather than the sun, like some of the calendars used to determine when holidays such as Ramadan begin. The lunar landscape refers to the moon's rocky, crater-filled terrain, and people sometimes describe very barren or desolate places on Earth as looking lunar.

The opposite of lunar is solar, which relates to the sun. So while solar panels capture energy from the sun, future lunar bases might be built on the moon's surface.