“Bert”— A neutrino that exploded in the IceCube detector in August 2001. Keep in mind that the detector is one kilometer high and one kilometer wide, so Bert (and Ernie, below) would have more than filled a professional footballs stadium.
The first very high-energy neutrino detected by IceCube. “Bert” was detected in August 2011 and deposited 1.04 PeV (petaelectronvolts) of energy into the ice. It was the highest-energy neutrino that had ever been observed at the time.
The size of the blobs symbolize the amount of light that hit each light detector in the IceCube array, and their color indicates when the light hit each detector (red is early, yellow to green is late).
More details on Bert and Ernie at http://arxiv.org/abs/1304.5356