This NASA website contains extensive information on sun spots and sun spot prediction. Users have access to several forms of graphical and numerical data such as sun spot numbers, the Maunder minimum, the Butterfly diagram, the Greenwich sunspot data and sun spot cycle predictions. The site also includes a wealth of information about the sun and NASA's ongoing sun research. Full description.

The Solar and Heliospheric Observatory (SOHO) project is being carried out between the European Space Agency and NASA. The goal of the observatory is to gather information about and images of the sun and space weather. This site contains the very latest images from the SOHO observatory. Images are available in a variety of sizes to download and a near real-time screen saver of SOHO images is also ... Full description.

NASA Astronomy Photo of the Day website hosted this photo of Earth at night in November 2000. The photo shows what Earth looks like at night with urban centers highlighted by concentrations of city lights. The image is a composite of hundreds of satellite photographs taken by orbiting Defense Meteorological Satellites Program satellites. Full description.

Volcanoes of Other Worlds explores and compares volcanism on other planets. What do we know about plate tectonics on other planets? Planetary bodies highlighted include the Earth's Moon, Mars, Venus and Jupiter's moon Io. Users can also link to Volcano World, an excellent web-source of volcano information. Full description.

There are currently millions of man-made orbital ruins that make up "space junk". Space junk can be anything from hatches blown off space modules, paint fragments from the space shuttle, or satellites that no longer work. On this website you will help to capture junk that's floating out there in space. Each time you capture junk, you also find a short description of the junk, how it arrived in space ... Full description.

This page describes the tilt of the Earth's axis, its elliptical orbit, the length of the year and their relation to certain long-term cycles. Topics include the Milankovitch Cycles (cyclic changes in the direction of the Earth's rotation axis in space) and changes in obliquity (the tilt of the Earth's axis with respect to a direction perpendicular to its orbital plane). Full description.

Split-screen technology is utilized for an electronic peer review assignment that has students justify whether humans should continue their investigations of the Red Planet or not. This Starting Point page builds a context for the activity by describing the learning goals, teaching notes and materials, and recommending assessment methods. References and resource links are included. Full description.

This article is written by a planetary science teacher, many of whose teenaged students, like many young Americans, believe that aliens have visited the solar system and left monuments behind. She uses recent photos of the "face on Mars" to demonstrate to them how an "obvious" alien artifact looks much more ordinary in photos taken at different times of the Martian day. This demonstration engages ... Full description.

Astrobiology Magazine is an online service that provides summaries of scientific articles relevant to astrobiology. Specific topics include microbiology, paleontology, astronomy, climate history, planetary studies and space technology. The website is updated daily and free to access, however users must register to use the site. Users may follow links to an image gallery, book reviews, and a downloadable ... Full description.

The National Geophysical Data Center (NGDC) offers text descriptions of composite, individual and archival Total Solar Irradiance (TSI) data from various satellites. TSI describes the radiant energy emitted by the sun over all wavelengths that falls each second on one square meter outside the earth's atmosphere. Data is gathered as this radiant energy is absorbed into a cavity on a satellite and is ... Full description.