The void that exists beyond Earth's atmosphere. Above 120 km, very little atmosphere remains, so objects can continue to move quickly without extra energy. The space between the planets is not entirely empty, but filled with the tenuous gas of the solar wind as well as dust.
http://image.gsfc.nasa.gov/poetry//ask/askmag.html Well-organized NASA site with answers to questions about astronomy and space. The site endeavours to send a reply to any question about space and astronomy within three days. There are useful links to question archives, general files, and other space-related sites.
http://www.space.com/ Latest news on space exploration, plus space quizzes, games, and other fun stuff. The site also includes a children's page with activities.
Subjects: Astronomy and Astrophysics.