“Bert” and “Ernie”
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).
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 football stadium. The timescale is also stretched out: the duration of these events was only about two millionths of a second.