Thanks to data collected from NASA's Solar Terrestrial Relations Observatory (STEREO) and advances in modeling, scientists can for the first time watch a coronal mass ejection from its formation on the sun to its impact with the Earth's magnetosphere.
The most powerful CMEs, enormous magnetized clouds of electrified gas emitted from the sun, that hit the Earth's protective magnetic field can disrupt satellites, radio signals and even the electric grid.
Now, almost five years since the launch of satellites STEREO A and STEREO B, scientists have a clear view of space weather as CMEs transit from the sun to the Earth--marking a major milestone toward better forecasting of space weather events that could impact communications and electricity on Earth.
The National Oceanic and Atmospheric Administration can now forecast space weather to an eight-hour window, said Alysha Reinard, research scientist at NOAA during a NASA Helioscience webcast Aug. 18. Until very recently, scientists could only predict CMEs to a 12- to 24-hour window. "I think with the greater detail provided by Stereo we can likely get closer than that," she added.
Whether a CME will actually cause problems with the earth is largely dependent on the magnetic filed, said Reinard. CME fields are directional, a northward field or southward field could pull apart the Earth's magnetic filed in different ways.