Access Science: Learn how to forecast solar flares in your spare time

Fancy yourself as a sunspotter? If so, Sunspotter.org needs your time and brain power. The crowdsourcing website asks volunteers to compare pairs of sunspot groups and pick out the more complex ones. It's a straightforward task that verges on the addictive, as the images appear, showing patterns snapped from the sun's surface by the European Space Agency and Nasa Solar and Heliospheric Observatory spacecraft.

Why the need to look at groups of sunspots and, particularly, their complexity? “Our lab is obsessed with trying to forecast solar flares, or emissions of high-energy radiation from the sun’s surface, but that is a really hard thing to do,” says Prof Peter Gallagher of the school of physics at Trinity College Dublin, which is driving the Sunspotter.org initiative.

“We know flares come from sunspots, where you have strong magnetic fields, and for some reason it’s the big, complicated sunspots that produce solar flares rather than the small, simple ones.”

The scientists want to better understand how the complexity of a sunspot group is linked to the likelihood of flaring. They have written image- processing software that tracks data from sunspots and flares. “No matter how good image-processing software is, it still doesn’t do very well at recognising the complicated patterns that the human brain can pull out.”

Enter Sunspotter.org, which researcher Dr Paul Higgins started under the umbrella of the citizen science website Zooniverse.org.

Each sunspot image is compared several times, then the lab gets a ranked list of sunspot groups (from big and complex to small and simple) and they can link the data to patterns of solar flare eruptions. More than 13,000 people have contributed about 1.5 million rankings to the site.

"We will be writing papers from the results and publishing them in open-access journals so that the people who took part can see the findings," says Higgins, whose own research at Trinity and the Lockheed Martin Solar and Astrophysics Laboratory in California is looking at how groups of sunspots "talk" to each other through their magnetic field connections in the solar atmosphere. Claire O'Connell

READER QUESTION: IN SEARCH OF THE HOLE TRUTH 

• Question: If you dug a hole from the top of the Earth to the bottom, which way would you come out of the hole: head first or feet first? Ciaran

• Answer: Interesting question. We will have to consider it a thought experiment, as the practicalities of digging a hole through the centre of the Earth are beyond the bounds of engineering at the moment, and the heat of the planet's interior would not be compatible with human life. But, putting all that to one side, if you dig a hole that goes right through the centre of the Earth and jump through, you will actually not come flying out the other side of the planet. As you come up close to the surface on the other side of the Earth, you start to slow down, as the Earth is pulling you back down again. If there is no air friction or some other forces, you will simply oscillate up and down in the hole. If you go in feet first, you will come up at the other side feet first, provided that you don't spin out of control as you go through the centre of the Earth. Gravity is zero at the centre, so you might "lose your balance" as you go through. Prof Chris Bean, professor of geophysics in the school of geological sciences, UCD, with Claire O'Connell