Physicists have recalculated the mass of the Earth using more precise measurements, and they say the Earth is lighter than they thought.

European Space Agency is planning to send four satellites to study and map the Earth's magnetic field. Read about space weather forecasting.

Find out what the discovery of extraterrestrial gases on Earth means to scientists, and learn about the formation of buckyballs.

Learn about a developing NASA project known as the Solar Sail, a probe that would ride the solar wind at high speeds into interstellar space.

Scientists report that in March, 2001, the sun released the most powerful solar flare in more than a decade, creating auroras on Earth.

Scientists at Stanford University have discovered that parallel layers of gas within the sun rotate at different speeds. View graphics.