AuroraWatch

Aurora. Photo by remid0d0s0.

AuroraWatch is the outreach part of SAMNET, the Sub-Auroral Magnetometer Network. The idea is you sign up to an email service and then they’ll tell you when there’s likely to be auroral activity over the UK. If you struggle with waiting for an email, they’ve also provided details on how to build a magnetometer using a pop bottle. As you can see from above the Northern Lights can be very pretty, but there are a few more reasons for studying them than that.

Aurorae are formed when particles of the solar wind slam into the atmosphere around fifty to a hundred miles above the surface of the earth. These particles smack into atoms in the upper atmosphere and add energy to them. This excess energy is then emitted as light. By observing the colours emitted you can work out what’s up there. In this case the green is from oxygen, this probably isn’t that much of a surprise, but there are fainter colours in the atmosphere which might tell you a bit more abotu what’s up there.

The patterns of the aurorae depend on a few things. One is that you have to have particles spit out from the Sun to create these patterns. This varies in ways that aren’t fully understood. The Sun’s activity could have serious consequences for people on Earth. The Little Ice Age may have been a symptom of the Sun’s behaviour. It also literally has knock-on effects for satellites. High-energy particles impacting into satellites can overload them, and they’re not usually easily accessible to fix.

It also varies with terrestrial activity. The particles are charged and so the Earth’s magnetic field channels them to hit the atmosphere at certain points. Again the generation of the Earth’s magnetic field isn’t fully understood, but if it was weaker or didn’t exist then these same particles could make life impossible on Earth. So by looking up you can learn what’s happening beneath your feet.

AuroraWatch looks like an excellent way to keep up with some of this research, but you may have to be quick. PPARC is planning to withdraw funding from April 2007.