Artist's rendition of a CME swirling outward through the Solar System.
Click on image for full size

Space Weather throughout the Solar System

There is a giant magnetic "bubble" in space around the Sun. That "bubble" is called the heliosphere. In a sense, we Earthlings live within the outer atmosphere of our Sun. The solar wind fills the heliosphere with energetic particles and magnetic fields, extending the outermost edges of the solar atmosphere beyond the orbit of Pluto. Instruments on interplanetary spacecraft help us probe the heliosphere, while those same spacecraft are at risk from damage by space weather storms. Some day astronauts will venture far from Earth, and their safety will depend upon our knowledge of radiation throughout the heliosphere.

Within the heliosphere, the solar wind interacts with planets, moons, and other smaller bodies in our Solar System. Some planets possess strong global magnetic fields that interact with the solar wind. This interplay gives rise to complex, dynamic systems of radiation belts, flows of electrical currents, and auroral displays in the neighborhoods of such planets. Planets lacking magnetic fields are left unshielded from bombardment by the solar outpourings. A few moons have magnetic fields and magnetospheres as well, though most do not. Comets, with their long tails of dust and ionized gases, are the bodies most visibly influenced by the solar wind.

Stars, and the planetary systems that surround them, change over time. Our Sun, though dimmer, was more active in its infancy. In recent years we have become able to observe the heliospheres of other stars, helping us learn about our own Sun via comparison. Early, active phases of a star's life exert a powerful influence over the formation of planets in their vicinity.

Last modified September 4, 2008 by Randy Russell.

You might also be interested in:

Cool It! Game

Check out our online store - minerals, fossils, books, activities, jewelry, and household items!...more

Particle Radiation

One main type of radiation, particle radiation, is the result of subatomic particles hurtling at tremendous speeds. Protons, cosmic rays, and alpha and beta particles are some of the most common types...more

The Magnetic Field

The force of magnetism causes material to point along the direction the magnetic force points. As shown in the diagram to the left, the force of magnetism is illustrated by lines, which represent the force....more

Detecting Planetary Magnetism

A magnetometer is an instrument for measuring magnetic fields. Many spacecraft carry magnetometers to measure the magnetic fields around planets. When a spacecraft makes those measurements, what do the...more


Radiation comes in two basic types: electromagnetic radiation transmitted by photons, and particle radiation consisting of electrons, protons, alpha particles, and so forth. Electromagnetic radiation,...more

Planetary Magnets

The Earth is a good example of a planetary dipole, where the lines of force point in a direction out of the South (magnetic) Pole and into the North (magnetic) Pole. Planets can also show evidence of quadrupoles...more


A magnetosphere has many parts, such as the bow shock, magnetosheath, magnetotail, plasmasheet, lobes, plasmasphere, radiation belts and many electric currents. It is composed of charged particles and...more

Radiation Belts

The Earth's radiation belts are just one part of the system called the magnetosphere. The radiation belts of the Earth are made up of electrons, protons and heavier atomic ions. These particles get trapped...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA