text: When high-energy electrons and ions from the sun hit Earth’s upper atmosphere, they can excite atoms and create fantastic colours - which we see on the ground as auroras. And now a study has claimed that we could create our own auroras, by firing a particle accelerator into the sky from space. The intriguing research says that a beam fired from the machine would create artificial auroras  – and it could even create lightning in the atmosphere. Scientists in California have described how to create artificial auroras on Earth. They said a particle accelerator could be sent 185 miles (300km) up into space (illustration of a satellite in orbit shown). It would then fire high-energy beams back at Earth's atmosphere . The study, published in the Journal of Geophysical Research, was picked up by Mark Zastrow from Eos. The accelerator being proposed would be three times stronger than anything like it before, producing a beam with particles 0.5 to 10 million electron volts. Pulses of the beam would last just 0.1 microseconds. The accelerator would be located in space, 185 miles (300km) above the ground, and would fire back towards Earth's atmosphere. There are two types of auroras on Earth - the Aurora Borealis in the Northern Hemisphere, known as the Northern Lights, and the Aurora Australis in the Southern Hemisphere, known as the Southern Lights. Auroras occur when highly charged electrons from the solar wind collide with atoms of oxygen and nitrogen in the earth's atmosphere at altitudes from 20 to 200 miles (32 to 320km) above the planet’s surface. The interactions between the charged particles give off light. Auroral displays appear in many colours: red, yellow, green, blue, and violet. The color of the aurora depends on which atom is struck, and the altitude of the meeting. The common green hue is caused by colliding oxygen molecules at altitudes of up to 150 miles (240km). It would be based on a instrument called the Compact Particle Accelerator for Space Science (Compass), which is being developed by the SLAC National Accelerator Laboratory and SRI International, both in California. ‘The authors say that employing such instrumentation would offer many scientific opportunities to study the behaviour of particles in the upper atmosphere,’ wrote Mr Zastrow. ‘The paths of the electrons would trace out the arcing field lines of Earth’s magnetic field, illustrating how they bend and snap during the intense geomagnetic activity caused by solar storms. ‘As they descend into the Earth’s atmosphere, some of the electrons would strike atmospheric molecules, producing visible aurora-like emission.’ He added that the beam might even be able to trigger different forms of lightning, including red sprites and blue jets. For now the idea is only a concept, and there are no concrete plans to build it. But the team says that by proving it works, it could be a step towards actually making it. There are two types of auroras on Earth - the Aurora Borealis in the Northern Hemisphere, known as the Northern Lights, and the Aurora Australis in the Southern Hemisphere, known as the Southern Lights. Shown is the Aurora Borealis above the Snaefellsnes Peninsula in Iceland . It would not be the first experiment with Earth’s atmosphere, though. In Alaska there is an ionospheric research programmed called the High Frequency Active Auroral Research Program (Haarp). Haarp is jointly funded by the US Air Force, the US Navy, the University of Alaska, and the Defense Advanced Research Projects Agency (Darpa). It was established to analyse the ionosphere - a region of the upper atmosphere - and investigate the development of ionospheric enhancement technology for radio communications and surveillance. In Alaska there is already an ionospheric research programmed called the High Frequency Active Auroral Research Program (Haarp), pictured. It was established to analyse the ionosphere - a region of the upper atmosphere - and investigate the development of ionospheric enhancement technology . The station regularly uses a tool called the Ionospheric Research Instrument (IRI), a high-power radio frequency transmitter facility operating in the high frequency band. It is used to temporarily excite a limited area of the Ionosphere. Haarp has been the subject of numerous unfounded conspiracy theories. It has been blamed for hurricanes, thunderstorms, major power outages and more, but no convincing evidence supports any of the claims.
target: Scientists in California described how to create artificial auroras on Earth .
  They said a particle accelerator could be sent 185 miles up into space .
  It would then fire high-energy beams back at Earth's atmosphere .
  This would create auroras to study - and even types of lightning .