"In terms of space weather forecasting, we're where weather forecasters were in the 1950s. They didn't see hurricanes until the rain clouds were right above them; in our case, we can see storms leaving the sun but we have to make guesses and use models to figure out if and when it will impact Earth." Dr. Michael Kaiser, Project Scientist for STEREO at NASA Goddard Space Flight Center"

Helophysics

We live in the extended atmosphere of an active star. While sunlight enables and sustains life, the Sun's variability produces streams of high-energy particles and radiation that can affect life.

Under the protective shield of its the magnetic field and atmosphere, the Earth is an island in the solar system where life has developed and flourished. The origins and fate of life on Earth are intimately connected to the way the Earth responds to the Sun's variations. Understanding the changing Sun and its effects on the Solar System, life, and society is the goal of the Sun-Earth Connection Theme.

What is "space weather"?

Everyone is familiar with changes in the weather on Earth. But "weather" also occurs in space. Just as it drives weather on Earth, the Sun is responsible for disturbances in our space environment.

Besides emitting a continuous stream of plasma called the solar wind, the Sun periodically releases billions of tons of matter in what are called coronal mass ejections. These immense clouds of material, when directed towards Earth, can cause large magnetic storms in the magnetosphere and the upper atmosphere.

The term space weather generally refers to conditions on the Sun and in the solar wind, magnetosphere, ionosphere, and thermosphere that can influence the performance and reliability of space-borne and ground-based technological systems and can endanger human life or health. Storms in space

Magnetic storms produce many noticeable effects on and near Earth:

• Aurora borealis, the northern lights, and aurora australis, the southern lights
• Communication disruptions
• Radiation hazards to orbiting astronauts and spacecraft
• Current surges in power lines
• Orbital degradation
• Corrosion in oil pipelines