Part 1: Why we need an early-warning system for solar ejections
When strong magnetic fields crop up along the surface of the Sun cause the atmosphere above to twist, the buildup of magnetic energy leads to a sudden release, called a solar flare. When that energy reaches Earth, it has the capacity to wreak havoc.
Part 1 of 7. This is a seven-part series anticipating the launch of the first mission to the sun, NASA’s Parker Solar Probe. The University of Michigan’s Justin Kasper, a climate space science professor, serves as one of the principal investigators for the mission.
When we talk about solar weather, we’re talking about electromagnetic activity in the sun’s atmosphere that could potentially cause disturbances on Earth. And when we talk about “disturbances,” we’re talking about the potential to knock out huge swaths of our electrical grids for months at a time.
That threat is among the driving forces behind NASA’s Parker Solar Probe, set to launch in early August. Justin Kasper, a climate and space science professor at U-M, is serving as a principal investigator on the mission.
Strong magnetic fields that crop up along the surface of the sun cause the atmosphere above to twist. The buildup of magnetic energy leads to a sudden release, called a solar flare, that ejects radiation outward.
“A large coronal mass ejection might involve an amount of plasma or radiation in the solar atmosphere that’s roughly equal to the amount of water in Lake Michigan that goes from rest to about 3 million miles an hour in tens of minutes,” Kasper said. “That’s an incredible amount of energy.”
When that energy reaches Earth, it has the capacity to wreak havoc. Most vulnerable are our electrical system’s massive transformers. Because they’re custom-made at a cost of tens of millions of dollars apiece, there are no spares. And because they can take up to six months to manufacture, a major failure could have lasting consequences.
Our current early-warning system for such threats comes from two sources. The first is the Solar Dynamics Observatory (SDO), essentially a floating camera orbiting the Earth. It snaps images of what’s going on in the sun’s atmosphere – a terabyte a day – and transmits them back to Earth.
The second part is the Deep Space Climate Observatory (DSCOVR). It sits at Lagrange Point 1, where the gravitational pulls of the sun and Earth cancel each other out. Capable of analyzing the solar wind, DSCOVR’s onboard plasma magnetometer suite measures the electrons, charged particles and magnetic field of the wind as it passes by, relaying the data back to Earth in real time.
“On the ground, we’re able to process that data immediately to tell if a shockwave has reached that spacecraft,” Kasper said. “If a coronal mass ejection reaches L1, we can detect it. That’s usually enough warning, even with a strong, fast-moving event, to give people on Earth about an hour to prepare.”
Combined, they provide us with roughly one hour of warning – potentially enough to take precautions to protect power grids.
The Parker Solar Probe will gather data from the corona to help us better understand the images we see from across the galaxy. Eventually, it could lead to an early-warning system that gives us several days advance notice.