Sit under the stars
One of the most vivid memories you can create in the minds of Scouts is to spend a night out under the stars. A groundsheet on the ground and a warm sleeping bag, plus the talk of stars and planets not to mention spaceships and ET life on other planets. You will nearly always end up talking about the wonder of the Universe and the possible place of God in its creation.
You could use Google's Sky Map on android mobile phones to identify constellations - unless you know them yourself!
Use the opportunity to make it as educational as you like - there are loads of parts of the Astronomer badge that could be covered.