This activity is a good follow up activity after a discussion on what is needed for sustaining life (solar energy, water, and an atmosphere).
This activity allows students to compare the conditions for life on other planets. Students can utilize NASA's "Solar System Exploration" site to gather information about temperature, water, and composition of the atmosphere on other planets.
I suggest that you group students and assign each group a planet to research. Students can then share their research with the class. All of the information can be recorded on this table. They can then determine which planets may be able to sustain some form of life, based on the information in the table.