With suggestions and input from the class, brainstorm a list of qualities that make Earth livable for human beings. Write the list on the board and circle or put stars next to the elements that are the most important. Have students conduct individual or group research projects to figure out which other planet is best suitable for supporting human life. After they have found their results, they should defend them to the rest of the class.
Purchase space food from a specialty store or an online shop for science experiments. Allow the children to eat the food while following rules of space dining etiquette. For example, they have to eat directly out of the food packages and use a clamp when utilizing a straw. As they are eating, have the students create a list of how the space food is both different and similar to the regular food items they match up with.
Assign students to create a model of outer space, including all of the planets in the solar system. You may also ask them to include specific stars or constellations. However, in addition simply to creating a model, they must use a scale. They will need to produce a scale that shows the measurements they are working with and make sure that the physical size of each planet and the distance among them are in line with their scale.
Another topic of interest for many students is the phases of the moon. The phases of the moon are an observable phenomenon, but there is still more to be learned than just what can be seen. For example, encourage students to pursue a topic such as determining how the lunar rotation and revolution rate compare. Observing the moon and its angular changes in position over the course of a month or two will help students with this project. For a more simple project at an earlier school age, have students draw pictures of the different phases of the moon.