Astronaut Warning System for Outbursts from the Sun
The Sun is acting up again!
A huge coronal mass ejection on the Sun was recorded on July 12. Forecasters expect the cloud of energetic particles to arrive at Earth on July 14th. Its impact could spark moderate to severe geomagnetic storms, allowing auroras to be seen at lower latitudes than usual.
Then on July 2 a flare came from a large sunspot in the Sun’s southern hemisphere. The flare caused brief radio interference over Europe.
But massive explosions on the Sun unleash radiation harmful to astronauts in space. How best to provide advance warning from such outbursts?
Researchers from the U.S. and South Korea have developed a warning system capable of forecasting the radiation from these violent solar storms nearly three hours in advance, giving astronauts, as well as air crews flying over Earth’s polar regions, time to take protective action.
Traveling nearly at the speed of light, it takes just 10 minutes for the first particles ejected from a solar storm to reach Earth.
The Sun is now moving into a peak period of solar storm activity, which generally occurs every 11 years. The solar storms, flares and coronal mass ejections threaten the electrical system on Earth…in addition to space travelers and aircraft pilots and passengers.
Fast-moving, slow-going particles
The researchers used data collected by two neutron monitors installed years ago at the South Pole — one inside and one outside the Amundsen-Scott South Pole Station — to determine the intensity of the high-energy, fast-moving particles that arrive to Earth first from solar storms.
These particles can carry energies over 500 megaelectron volts (MeV). That’s over 500 million electron volts!
By examining the properties of these first-arriving particles, the scientists can make useful predictions about the slower-moving, yet more dangerous particles to follow.
“These slower-moving particles are more dangerous because there are so many more of them. That’s where the danger lies,” said John Bieber at the University of Delaware’s Bartol Research Institute, based in the Department of Physics and Astronomy.
The system developed by specialists at the University of Delaware and from South Korea’s Chungnam National University and Hanyang University provides a warning time up to 166 minutes.
That would give astronauts on deep space flights time to seek out an armored area in their spacecraft, Bieber says, and pilots flying in Earth’s polar regions, where the planet’s protective magnetic field is weaker, time to reduce their altitude.
Most astronauts have flown in low Earth orbit in recent years, but if we go back to the Moon or decide to send humans to Mars, we need to think about these things, Bieber says.
The research was funded by the National Research Foundation of Korea through the South Korean government and by the U.S. National Science Foundation, NASA and the NASA/EPSCoR program.
By Leonard David