This Why Files article discusses newly discovered planets outside our solar system and focuses attention on the question: Are we alone in the universe? Topics covered are: how did scientists discover the planets, what besides planets could they be, the upcoming collision of the solar system with a dense cloud of interstellar gas, and scientists' search for intelligent life in outer space. An update ... Full description.

In this article, The Why Files investigates comets. Topics include their origins, what they are made of, where in the solar system they come from, and others. Several of the more famous comets, such as Halley's, are mentioned, and there is information on the latest encounter with a comet, the Deep Impact mission to Tempel 1. Myths and legends about comets are also discussed. A classroom activity is ... Full description.

This lesson plan is part of the DiscoverySchool.com lesson plan library for grades 9-12. It focuses on how astronomers use light properties, and the doppler-effect (redshift), to determine that stars are moving away from the Earth and the universe is expanding. It includes objectives, materials, procedures, discussion questions, evaluation ideas, performing extensions, suggested readings, and vocabulary. ... Full description.

This lesson plan is part of the Center for Educational Resources (CERES), a series of web-based astronomy lessons created by a team of master teachers, university faculty, and NASA researchers. In this activity, students view images of galaxies and develop a classification scheme. They then compare and contrast their scheme with that developed by Edwin Hubble. This lesson contains expected outcomes ... Full description.

This site provides information on volcanoes on Mars, including shield volcanoes, large volcanic cones, unusual patera structures, mare-like volcanic plains, and a number of other smaller features. It also compares volcanism on Mars and the Earth's Moon. Full description.

Black holes are some of the strangest objects in the universe. While the physics of these objects is not understood, and they cannot be seen directly, indirect observations have revealed for certain that black holes do exist. This animation shows an artist's conception of what it might be like to see a super-massive black hole in the center of a spiral galaxy. A background essay and list of discussion ... Full description.

This reference page serves as a precursor to an activity on fusion reactions within stars. It explains that in the evolutionary path of high mass stars, once stars are five times or more massive than our Sun they reach the red giant phase and, being unstable, they progress from red giant to supernova. While many of the more common elements are made through nuclear fusion in the cores of stars, it ... Full description.

In this article, The Why Files examines our star, the Sun, and its features. It discusses how the Sun creates energy through fusion and the solar maximum that occurs every 11 years. Solar wind, solar prominences, solar flares, and sunspots are all described and explained. There are sections on sunquakes, which explains how we use vibration data to tell us about the Sun, on the Sun's magnetic field, ... Full description.

This Why Files article investigates the neutrino particle, and why scientists are interested in finding them. The neutrino was 'invented' by a physicist to balance out an equation in the 1950's, and ever since, astronomers and physicists have been looking for these particles as traces to the early universe. The article looks at how neutrinos can be detected in Antarctica, and the universal clues they ... Full description.

In this lesson plan, students explore how the universe has evolved since the theoretical Big Bang and create dramatizations of various eras in cosmic evolution. This page provides objectives, resources/materials, a related article and timeline, activities, follow-up questions, evaluation ideas, vocabulary, interdisciplinary connections, and links to additional information. Full description.