Scientists discover where cosmic rays come from

By Mark Waghorn via SWNS

Cosmic rays that endanger satellites, airplanes and manned missions to Mars come from magnetic fields in the outer atmosphere of the sun, according to new research.

They can accelerate ions and electrons close to the speed of light - posing a risk to electronic infrastructure.

Scientists in the US have identified their source for the first time - offering hope of improving safety of commercial and space flight.

They used supercomputers to simulate when and how they are born in turbulent environments.

It paves the way for more accurate forecasts of when dangerous bursts are most likely to occur.

"This exciting new research will allow us to better predict the origin of solar energetic particles and improve forecasting models of space weather events, a key goal of NASA and other space agencies and governments around the globe," said lead author Dr. Luca Comisso, of Columbia University.

"Within the next couple of years NASA's Parker Solar Probe, the closest spacecraft to the sun, may be able to validate the paper's findings by directly observing the predicted distribution of high-energy particles that are generated in the sun's outer atmosphere."

In high enough numbers, they pose a radiation risk to astronauts and people traveling in planes.

They bombard earth and object's outside the planet's atmosphere at unpredictable times - destroying electronic equipment.

It is a vexing problem about the weather in outer space that astronomers have been trying to solve for decades.

A clear pattern of how and when flare-ups will occur has remained enduringly difficult to identify despite their best efforts.

The flare-ups can even trigger showers strong enough to reach people in jets flying over the North Pole.

The sun and other stars' outer atmosphere consist of particles of plasma - the fourth state of matter distinct from liquid, gas and solids.

The models mimicked the atmospheric conditions on the sun - providing the most extensive data of its kind to date.

They answer questions scientists have been investigating for more than seven decades.

In 1949, the physicist Enrico Fermi began to investigate magnetic fields in outer space as a potential source of high-energy particles entering Earth's atmosphere.

Since then, scientists have suspected the sun's plasma is to blame - but definitive proof has been elusive.

Understanding where they come from is vital, as it can provide scientists and officials with valuable seconds and minutes to prepare before they hit.

They can arrive within ten minutes of leaving the sun - and can cause damage to astronauts, spacecraft and even airlines.

Our star sun is a huge ball of electrically-charged hot gas that moves, generating a powerful magnetic field.

It goes through a sequence called the solar cycle. Every 11 years or so the field completely flips - with the north and south poles switching places.

The solar cycle affects activity on the surface of the sun - such as sunspots. One way to track the solar cycle is by counting the number of sunspots.

The study part funded by NASA has implications far beyond our own solar system. The vast majority of the observable matter in the universe is in a plasma state.

Shedding light on how they can be accelerated to high-energy levels is an important new area of research.

They are routinely observed not just around the sun but also in other environments across the universe - including the surroundings of black holes and neutron stars.

Further simulations could be run in other contexts to understand how and when distant stars, black holes, and other entities in the universe will generate their own bursts of energy.

"Our results center on the sun but can also be seen as a starting point to better understanding how high-energy particles are produced in more distant stars and around black holes," said co author Dr. Lorenzo Siron.

"We have only scratched the surface of what supercomputer simulations can tell us about how these particles are born across the universe."

The study is in The Astrophysical Journal Letters.