Why should we care about space weather?

The storms caused by the Sun -- scientists call them geomagnetic storms -- can play havoc with modern technology such as cell phones, pagers, electric power systems, satellites, and communications signals (TV, radio, navigation). We have come to depend upon these technologies for everyday tasks, and most of us are lost without them. Yet those toys and tools operate on electromagnetic energy; at the same time, the Sun and Earth's atmosphere are huge producers of such energy, and they can sometimes overwhelm our comparatively small gadgets.

Can we predict space weather?

With several government satellites and ground-based observatories, scientists can observe in real-time what is happening on the Sun and what is happening right now in the space around Earth. They can also make some well-educated guesses about whether a space storm will hit Earth. But so far, they don't have enough reliable information to predict the severity or timing of such storms until about 30-40 minutes before they happen. But even that short amount of time can be useful to some people in the satellite and power industries.

How does space weather affect satellites (including weather satellites)?

Intense bursts of energy from the Sun and from Earth's radiation belts Earth can cause electrical shorts and sparks inside the computer brains of satellites, causing them to spin out of control or shut down. The slow, steady bombardment of particles in space can degrade the solar panels so that a satellite cannot create enough energy to operate. The heating of the upper atmosphere by can cause a satellite to slow down and drop out of orbit. And the signals that are sent between the ground and satellites can be distorted by disturbances in the ionosphere.

Does space weather affect weather and climate on Earth?

The Sun drives the weather and seasons on Earth with its visible, warming light. But storms from the Sun do not affect the weather on a day-to-day basis because they don't generally change the amount of heat and light the sun is emitting. In recent years, however, scientists have found evidence that the output from the Sun seems to vary on much longer scales, from dozens of years to hundreds and thousands of years. There are indications that these changes can lead to climate changes on Earth by altering wind patterns or the formation of clouds.

Are astronauts in danger from space weather?

There is definitely a risk to astronauts working on the shuttle or space station, though it is relatively small. Most of the time, they are working well beneath the protective magnetic field of Earth and far from the auroral zones, so they are naturally protected against most damaging radiation. Also, NASA closely monitors how much radiation astronauts receive. Particles from space weather storms can cause elements of radiation sickness if the doses ever got too high. Too date, that has never happened, but during the Apollo days, there was a near-miss. A huge flare in August 1972 might have killed the astronauts if they had been on their way to the Moon at the time.

Can space weather hurt humans on Earth?

On the surface of the Earth, we are protected from solar radiation by our dense atmosphere and by Earth's magnetic field. About the only thing that gets to the ground is visible light, some radio emissions, and some ultraviolet light. But when we fly in airplanes -- particularly along polar routes, say from New York to Tokyo -- we move up above some of that protective atmosphere and we receive more radiation from the Sun. During a particularly intense storm, you could receive the equivalent of an extra chest X ray. It is not a life or death situation, and people shouldn't be scared to fly. But frequent flyers and flight crews should be aware that they might be receiving as much radiation as someone working in a nuclear power plant.