This is a painting craft project that I did with my 5yr old son, but it is possible for children of other ages to do.
The activity can be done with relatively cheap supplies.
Time: 15 minutes of craft time, but a few hours paint drying time.
Age: Any Age
Blank canvas (I used an A5 size, $1.50 from the nearest dollar store)
Black and white acrylic paint
Star stickers (Mine were $1 from the nearest dollar store)
Choose a handful of star stickers (not all of them) and place randomly on canvas
Paint over the entire canvas (including star stickers) in blank paint with a paintbrush, and leave to dry (an hour or so in the sun would be ideal)
Once dry, stick more star stickers randomly over the now black painted canvas.
Get a sponge and dab a very slight amount of white paint all over the canvas. Tip - do not put too much white paint on the sponge otherwise the white paint will be too splodgey, and you will not get the same 'galaxy' effect.
Once the white paint is dry (does not take as long to dry as before) gently peel off the star stickers to reveal your stars. The trickiest part of this project is removing the star stickers painted over with black paint, some of these stars we decided to leave in place.
If you have star stickers leftover, you could add some extras onto the finished painted piece at the end.