MoonKAM Mission Interrupted by Solar FlareGRAIL mission operators were excited to extend MoonKAM so students had more time to request photos of the lunar surface. But then particles and radiation from a solar flare zapped the GRAIL satellites and damaged the MoonKAM cameras. The extended mission was interrupted. This glitch does have an upside—it gives MoonKAM classrooms a chance to learn about a critical aspect of space exploration. Damage from solar flares is a hazard scientists must plan for and deal with on all space missions.
Solar flares are sudden brightenings on the Sun’s surface that result from magnetic disturbances. These disturbances are called sunspots, and scientists don’t completely understand what causes them. When a sunspot appears, it hurls highly energized particles (protons, electrons, and some ions) and electromagnetic radiation (X-rays and gamma rays) into space. A solar flare often is followed by a coronal mass ejection, or CME. When this happens, even more charged particles and electromagnetic radiation shoot into space. The particles and energy reach Earth in a few days. When the particles hit Earth’s natural magnetic field, they generate a geomagnetic storm. This disturbance in Earth’s magnetic field can disrupt electrical grids and equipment powered by electricity.
Solar flares are invisible to the naked eye. The electromagnetic energy they release is not part of the spectrum of visible light that can be detected by our eyes and processed by our brains. The flares must be observed and studied with special instruments and satellites. These instruments show that solar flares and CMEs are dramatic, high-energy events. This video, produced by NASA’s Solar Dynamics Observatory, demonstrates the incredible power of a solar flare.
Solar flares can happen at any time, but they usually occur as part of an 11-year cycle of increased and decreased activity in the Sun known as the solar cycle. During a solar maximum, solar flares erupt frequently—sometimes as many as 20 per day. During a solar minimum, solar flares occur rarely, if at all. The next solar maximum is expected to peak sometime in 2013, so we can expect a lot of solar flares over the coming year.
It’s fairly common for blasts of solar particles and radiation to damage instruments on satellites and spacecraft. The instruments may be knocked out of commission for a while—or completely shut down. This damage can disrupt communications on Earth. Federal agencies keep an eye on the Sun and issue bulletins when there is a lot of solar activity. If there is enough warning, satellites can be repositioned to avoid the worst damage from solar flares. Also, satellite builders can install shields that partially protect instruments. But shielding is expensive, and it makes satellites heavier. The MoonKAM cameras aren’t shielded from solar flares.
Geomagnetic storms created by solar flares can mess up electrical equipment and shut down power grids. In 1989, damage from a huge solar flare blacked out all of Quebec, Canada, for 12 hours. As we use more kinds of technology, there are more ways solar flares can affect us—by interfering with GPS devices, cell-phone service, or ATM networks, for instance.
Solar flares spew out dangerous charged particles and radiation. But here on Earth, you don’t need to worry. Earth’s magnetic field and atmosphere protect us. There is less protection high in the atmosphere near Earth’s poles. So when big solar flares erupt, airlines reroute flights away from polar areas. For astronauts in space, though, solar flares are a serious concern. Particles from solar flares can penetrate spacesuits and damage astronauts’ cells and DNA. On the International Space Station, astronauts have some protection because the station is shielded, and it orbits within Earth’s magnetic field.