What do you think the above picture is? Let me save you the guesses - it is in fact the
magnetic field of the earth (or rather, a computer simulation of it)! The blue lines are
directed inwards and the yellow ones are directed outwards. Did you know that the reason
for the earth's magnetic field is still not well understood? For some reason, this picture
fascinates me. It is just so cool!

The picture was stolen from the astronomy picture of the day site (I highly recommend
the site). The copyright for the photo is owned by Gary A. Glatzmaier.